critical literature review advantages and disadvantages

Advantages and disadvantages of literature review

This comprehensive article explores some of the advantages and disadvantages of literature review in research. Reviewing relevant literature is a key area in research, and indeed, it is a research activity in itself. It helps researchers investigate a particular topic in detail. However, it has some limitations as well.

What is literature review?

In order to understand the advantages and disadvantages of literature review, it is important to understand what a literature review is and how it differs from other methods of research. According to Jones and Gratton (2009) a literature review essentially consists of critically reading, evaluating, and organising existing literature on a topic to assess the state of knowledge in the area. It is sometimes called critical review.

A literature review is a select analysis of existing research which is relevant to a researcher’s selected topic, showing how it relates to their investigation. It explains and justifies how their investigation may help answer some of the questions or gaps in the chosen area of study (University of Reading, 2022).

A literature review is a term used in the field of research to describe a systematic and methodical investigation of the relevant literature on a particular topic. In other words, it is an analysis of existing research on a topic in order to identify any relevant studies and draw conclusions about the topic.

A literature review is not the same as a bibliography or a database search. Rather than simply listing references to sources of information, a literature review involves critically evaluating and summarizing existing research on a topic. As such, it is a much more detailed and complex process than simply searching databases and websites, and it requires a lot of effort and skills.

Advantages of literature review

Information synthesis

A literature review is a very thorough and methodical exercise. It can be used to synthesize information and draw conclusions about a particular topic. Through a careful evaluation and critical summarization, researchers can draw a clear and comprehensive picture of the chosen topic.

Familiarity with the current knowledge

According to the University of Illinois (2022), literature reviews allow researchers to gain familiarity with the existing knowledge in their selected field, as well as the boundaries and limitations of that field.

Creation of new body of knowledge

One of the key advantages of literature review is that it creates new body of knowledge. Through careful evaluation and critical summarisation, researchers can create a new body of knowledge and enrich the field of study.

Answers to a range of questions

Literature reviews help researchers analyse the existing body of knowledge to determine the answers to a range of questions concerning a particular subject.

Disadvantages of literature review

Time consuming

As a literature review involves collecting and evaluating research and summarizing the findings, it requires a significant amount of time. To conduct a comprehensive review, researchers need to read many different articles and analyse a lot of data. This means that their review will take a long time to complete.

Lack of quality sources  

Researchers are expected to use a wide variety of sources of information to present a comprehensive review. However, it may sometimes be challenging for them to identify the quality sources because of the availability of huge numbers in their chosen field. It may also happen because of the lack of past empirical work, particularly if the selected topic is an unpopular one.

Descriptive writing

One of the major disadvantages of literature review is that instead of critical appreciation, some researchers end up developing reviews that are mostly descriptive. Their reviews are often more like summaries of the work of other writers and lack in criticality. It is worth noting that they must go beyond describing the literature.

Key features of literature review

Clear organisation

A literature review is typically a very critical and thorough process. Universities usually recommend students a particular structure to develop their reviews. Like all other academic writings, a review starts with an introduction and ends with a conclusion. Between the beginning and the end, researchers present the main body of the review containing the critical discussion of sources.

No obvious bias

A key feature of a literature review is that it should be very unbiased and objective. However, it should be mentioned that researchers may sometimes be influenced by their own opinions of the world.

Proper citation

One of the key features of literature review is that it must be properly cited. Researchers should include all the sources that they have used for information. They must do citations and provide a reference list by the end in line with a recognized referencing system such as Harvard.

To conclude this article, it can be said that a literature review is a type of research that seeks to examine and summarise existing research on a particular topic. It is an essential part of a dissertation/thesis. However, it is not an easy thing to handle by an inexperienced person. It also requires a lot of time and patience.

Hope you like this ‘Advantages and disadvantages of literature review’. Please share this with others to support our research work.

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Last update: 08 May 2022

References:

Jones, I., & Gratton, C. (2009) Research Methods for Sports Shttps://www.howandwhat.net/new/evaluate-website-content/tudies, 2 nd edition, London: Routledge

University of Illinois (2022) Literature review, available at: https://www.uis.edu/learning-hub/writing-resources/handouts/learning-hub/literature-review (accessed 08 May 2022)

University of Reading (2022) Literature reviews, available at: https://libguides.reading.ac.uk/literaturereview/starting (accessed 07 May 2022)

Author: M Rahman

M Rahman writes extensively online and offline with an emphasis on business management, marketing, and tourism. He is a lecturer in Management and Marketing. He holds an MSc in Tourism & Hospitality from the University of Sunderland. Also, graduated from Leeds Metropolitan University with a BA in Business & Management Studies and completed a DTLLS (Diploma in Teaching in the Life-Long Learning Sector) from London South Bank University.

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What is it?

Literature reviews involve collecting information from literature that is already available, similar to a long essay. It is a written argument that builds a case from previous research (Machi and McEvoy, 2012). Every dissertation should include a literature review, but a dissertation as a whole can be a literature review. In this section we discuss literature reviews for the whole dissertation.

What are the benefits of a literature review?

There are advantages and disadvantages to any approach. The advantages of conducting a literature review include accessibility, deeper understanding of your chosen topic, identifying experts and current research within that area, and answering key questions about current research. The disadvantages might include not providing new information on the subject and, depending on the subject area, you may have to include information that is out of date.

How do I write it?

A literature review is often split into chapters, you can choose if these chapters have titles that represent the information within them, or call them chapter 1, chapter 2, ect. A regular format for a literature review is:

Introduction (including methodology)

This particular example is split into 6 sections, however it may be more or less depending on your topic.

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Conducting a Literature Review

Benefits of conducting a literature review.

• Steps in Conducting a Literature Review
• Summary of the Process
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• Literature Review Tutorial by American University Library
• The Literature Review: A Few Tips On Conducting It by University of Toronto
• Write a Literature Review by UC Santa Cruz University Library

While there might be many reasons for conducting a literature review, following are four key outcomes of doing the review.

Assessment of the current state of research on a topic . This is probably the most obvious value of the literature review. Once a researcher has determined an area to work with for a research project, a search of relevant information sources will help determine what is already known about the topic and how extensively the topic has already been researched.

Identification of the experts on a particular topic . One of the additional benefits derived from doing the literature review is that it will quickly reveal which researchers have written the most on a particular topic and are, therefore, probably the experts on the topic. Someone who has written twenty articles on a topic or on related topics is more than likely more knowledgeable than someone who has written a single article. This same writer will likely turn up as a reference in most of the other articles written on the same topic. From the number of articles written by the author and the number of times the writer has been cited by other authors, a researcher will be able to assume that the particular author is an expert in the area and, thus, a key resource for consultation in the current research to be undertaken.

Identification of key questions about a topic that need further research . In many cases a researcher may discover new angles that need further exploration by reviewing what has already been written on a topic. For example, research may suggest that listening to music while studying might lead to better retention of ideas, but the research might not have assessed whether a particular style of music is more beneficial than another. A researcher who is interested in pursuing this topic would then do well to follow up existing studies with a new study, based on previous research, that tries to identify which styles of music are most beneficial to retention.

Determination of methodologies used in past studies of the same or similar topics.  It is often useful to review the types of studies that previous researchers have launched as a means of determining what approaches might be of most benefit in further developing a topic. By the same token, a review of previously conducted studies might lend itself to researchers determining a new angle for approaching research.

Upon completion of the literature review, a researcher should have a solid foundation of knowledge in the area and a good feel for the direction any new research should take. Should any additional questions arise during the course of the research, the researcher will know which experts to consult in order to quickly clear up those questions.

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Literature Review & Research Skills Guide: What is a Literature Review?

• Introduction
• What is a Literature Review?
• Your research topic
• Topic Analysis
• Developing a Search Strategy
• Preliminary Reading
• Use Primo Search
• Use Google Scholar
• Use Journal Databases
• Sage Research Methods
• Managing your literature review
• Evaluation & Critical Appraisal
• Referencing

What is a literature review

Once you have defined your topic, the next step is to start a literature review. A literature review summarises, interprets and critically evaluates material that has already been published on a topic. The purpose is to establish current knowledge of a subject, identify gaps, inconsistencies and relations in the literature as well as outline areas for additional research and/or define a topic of inquiry.

Adopted from Charles Sturt University Library. (2017). Literature review.  Retrieved from http://libguides.csu.edu.au/review

Types of literature reviews

The type of literature review you write will depend on your discipline and whether you are a researcher writing your PhD, publishing a study in a journal or completing an assessment task in your undergraduate study.

A literature review for a subject in an undergraduate degree will not be as comprehensive as the literature review required for a PhD thesis.

An undergraduate literature review may be in the form of an annotated bibliography or a narrative review of a small selection of literature, for example ten relevant articles. If you are asked to write a literature review, and you are an undergraduate student, be guided by your subject coordinator or lecturer.

Often the term "review" and "literature" can be confusing and used in the wrong context. Grant and Booth (2009) attempt to clear up this confusion by discussing 14 review types and the associated methodology, and advantages and disadvantages associated with each review.   For research students, especially those in EEB501, ERP502 or doctoral students, they will be undertaking a critical literature review.

Grant, M. J., & Booth, A. (2009).  A typology of reviews: an analysis of 14 review types and associated methodologies . Health Information & Libraries Journal, 26 , 91–108. doi:10.1111/j.1471-1842.2009.00848.x

What is the purpose or aim of the literature review?

A literature review should demonstrate your knowledge of the research that has been conducted in the past and should place your research in the context of this work. A literature review can have a number of purposes within a research project. These include:

• demonstrating and clarify your understanding of your field of research;
• identifying patterns and trends in the literature;
• identifying gaps in the literature and seek new lines of inquiry;
• identifying similarities and differences in previous research and place your work in perspective;
• justifying your own research;
• increasing your breadth of knowledge of your subject area;
• identifying seminal and influential published works in your field;
• identifying relevant journals, publishers and conferences to search;
• providing the intellectual context for your own work, enabling you to position your project relative to other work;
• identifying experts working in your field (a researcher network is a valuable resource);
• carrying on from where others have already reached.

Onwuegbuzie, A. J., & Frels, R. (2016). 7 steps to a comprehensive literature review : a multimodal & cultural approach . London : Thousand Oaks, California: SAGE Publications.

Randolph, J. J. (2009).  A guide to writing the dissertation literature review . Practical Assessment Research & Evaluation. 14 (Article 13), 1-13.

An Introduction to Literature Reviews

Please watch the following video:

where to start a literature review

There are many different types of resources which might offer information on the topic you are researching, but you need to consider whether the source is scholarly or authoritative enough for a literature review. Typically literature reviews are conducted by using journal articles, conference papers, book chapters, websites or standards.  

In addition, there is a range of new information sources that you may not have come across before, such as: 

• Internet resources
• Tracking citation
• Using Social Media
• Interlibrary loans

To keep your information organised, you might like to consider using a reference manager.  There are a number of different reference managers available to use, and they all have their own advantages and disadvantages. See the EndNote tab   to find further information on Charles Sturt University's bibliographic management software EndNote.

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The Literature Review: A Foundation for High-Quality Medical Education Research

a  These are subscription resources. Researchers should check with their librarian to determine their access rights.

Despite a surge in published scholarship in medical education 1 and rapid growth in journals that publish educational research, manuscript acceptance rates continue to fall. 2 Failure to conduct a thorough, accurate, and up-to-date literature review identifying an important problem and placing the study in context is consistently identified as one of the top reasons for rejection. 3 , 4 The purpose of this editorial is to provide a road map and practical recommendations for planning a literature review. By understanding the goals of a literature review and following a few basic processes, authors can enhance both the quality of their educational research and the likelihood of publication in the Journal of Graduate Medical Education ( JGME ) and in other journals.

The Literature Review Defined

In medical education, no organization has articulated a formal definition of a literature review for a research paper; thus, a literature review can take a number of forms. Depending on the type of article, target journal, and specific topic, these forms will vary in methodology, rigor, and depth. Several organizations have published guidelines for conducting an intensive literature search intended for formal systematic reviews, both broadly (eg, PRISMA) 5 and within medical education, 6 and there are excellent commentaries to guide authors of systematic reviews. 7 , 8

• A literature review forms the basis for high-quality medical education research and helps maximize relevance, originality, generalizability, and impact.
• A literature review provides context, informs methodology, maximizes innovation, avoids duplicative research, and ensures that professional standards are met.
• Literature reviews take time, are iterative, and should continue throughout the research process.
• Researchers should maximize the use of human resources (librarians, colleagues), search tools (databases/search engines), and existing literature (related articles).
• Keeping organized is critical.

Such work is outside the scope of this article, which focuses on literature reviews to inform reports of original medical education research. We define such a literature review as a synthetic review and summary of what is known and unknown regarding the topic of a scholarly body of work, including the current work's place within the existing knowledge . While this type of literature review may not require the intensive search processes mandated by systematic reviews, it merits a thoughtful and rigorous approach.

Purpose and Importance of the Literature Review

An understanding of the current literature is critical for all phases of a research study. Lingard 9 recently invoked the “journal-as-conversation” metaphor as a way of understanding how one's research fits into the larger medical education conversation. As she described it: “Imagine yourself joining a conversation at a social event. After you hang about eavesdropping to get the drift of what's being said (the conversational equivalent of the literature review), you join the conversation with a contribution that signals your shared interest in the topic, your knowledge of what's already been said, and your intention.” 9

The literature review helps any researcher “join the conversation” by providing context, informing methodology, identifying innovation, minimizing duplicative research, and ensuring that professional standards are met. Understanding the current literature also promotes scholarship, as proposed by Boyer, 10 by contributing to 5 of the 6 standards by which scholarly work should be evaluated. 11 Specifically, the review helps the researcher (1) articulate clear goals, (2) show evidence of adequate preparation, (3) select appropriate methods, (4) communicate relevant results, and (5) engage in reflective critique.

Failure to conduct a high-quality literature review is associated with several problems identified in the medical education literature, including studies that are repetitive, not grounded in theory, methodologically weak, and fail to expand knowledge beyond a single setting. 12 Indeed, medical education scholars complain that many studies repeat work already published and contribute little new knowledge—a likely cause of which is failure to conduct a proper literature review. 3 , 4

Likewise, studies that lack theoretical grounding or a conceptual framework make study design and interpretation difficult. 13 When theory is used in medical education studies, it is often invoked at a superficial level. As Norman 14 noted, when theory is used appropriately, it helps articulate variables that might be linked together and why, and it allows the researcher to make hypotheses and define a study's context and scope. Ultimately, a proper literature review is a first critical step toward identifying relevant conceptual frameworks.

Another problem is that many medical education studies are methodologically weak. 12 Good research requires trained investigators who can articulate relevant research questions, operationally define variables of interest, and choose the best method for specific research questions. Conducting a proper literature review helps both novice and experienced researchers select rigorous research methodologies.

Finally, many studies in medical education are “one-offs,” that is, single studies undertaken because the opportunity presented itself locally. Such studies frequently are not oriented toward progressive knowledge building and generalization to other settings. A firm grasp of the literature can encourage a programmatic approach to research.

Approaching the Literature Review

Considering these issues, journals have a responsibility to demand from authors a thoughtful synthesis of their study's position within the field, and it is the authors' responsibility to provide such a synthesis, based on a literature review. The aforementioned purposes of the literature review mandate that the review occurs throughout all phases of a study, from conception and design, to implementation and analysis, to manuscript preparation and submission.

Planning the literature review requires understanding of journal requirements, which vary greatly by journal ( table 1 ). Authors are advised to take note of common problems with reporting results of the literature review. Table 2 lists the most common problems that we have encountered as authors, reviewers, and editors.

Sample of Journals' Author Instructions for Literature Reviews Conducted as Part of Original Research Article a

Common Problem Areas for Reporting Literature Reviews in the Context of Scholarly Articles

Locating and Organizing the Literature

Three resources may facilitate identifying relevant literature: human resources, search tools, and related literature. As the process requires time, it is important to begin searching for literature early in the process (ie, the study design phase). Identifying and understanding relevant studies will increase the likelihood of designing a relevant, adaptable, generalizable, and novel study that is based on educational or learning theory and can maximize impact.

Human Resources

A medical librarian can help translate research interests into an effective search strategy, familiarize researchers with available information resources, provide information on organizing information, and introduce strategies for keeping current with emerging research. Often, librarians are also aware of research across their institutions and may be able to connect researchers with similar interests. Reaching out to colleagues for suggestions may help researchers quickly locate resources that would not otherwise be on their radar.

During this process, researchers will likely identify other researchers writing on aspects of their topic. Researchers should consider searching for the publications of these relevant researchers (see table 3 for search strategies). Additionally, institutional websites may include curriculum vitae of such relevant faculty with access to their entire publication record, including difficult to locate publications, such as book chapters, dissertations, and technical reports.

Strategies for Finding Related Researcher Publications in Databases and Search Engines

Search Tools and Related Literature

Researchers will locate the majority of needed information using databases and search engines. Excellent resources are available to guide researchers in the mechanics of literature searches. 15 , 16

Because medical education research draws on a variety of disciplines, researchers should include search tools with coverage beyond medicine (eg, psychology, nursing, education, and anthropology) and that cover several publication types, such as reports, standards, conference abstracts, and book chapters (see the box for several information resources). Many search tools include options for viewing citations of selected articles. Examining cited references provides additional articles for review and a sense of the influence of the selected article on its field.

Box Information Resources

• Web of Science a
• Education Resource Information Center (ERIC)
• Cumulative Index of Nursing & Allied Health (CINAHL) a
• Google Scholar

Once relevant articles are located, it is useful to mine those articles for additional citations. One strategy is to examine references of key articles, especially review articles, for relevant citations.

Getting Organized

As the aforementioned resources will likely provide a tremendous amount of information, organization is crucial. Researchers should determine which details are most important to their study (eg, participants, setting, methods, and outcomes) and generate a strategy for keeping those details organized and accessible. Increasingly, researchers utilize digital tools, such as Evernote, to capture such information, which enables accessibility across digital workspaces and search capabilities. Use of citation managers can also be helpful as they store citations and, in some cases, can generate bibliographies ( table 4 ).

Citation Managers

Knowing When to Say When

Researchers often ask how to know when they have located enough citations. Unfortunately, there is no magic or ideal number of citations to collect. One strategy for checking coverage of the literature is to inspect references of relevant articles. As researchers review references they will start noticing a repetition of the same articles with few new articles appearing. This can indicate that the researcher has covered the literature base on a particular topic.

Putting It All Together

In preparing to write a research paper, it is important to consider which citations to include and how they will inform the introduction and discussion sections. The “Instructions to Authors” for the targeted journal will often provide guidance on structuring the literature review (or introduction) and the number of total citations permitted for each article category. Reviewing articles of similar type published in the targeted journal can also provide guidance regarding structure and average lengths of the introduction and discussion sections.

When selecting references for the introduction consider those that illustrate core background theoretical and methodological concepts, as well as recent relevant studies. The introduction should be brief and present references not as a laundry list or narrative of available literature, but rather as a synthesized summary to provide context for the current study and to identify the gap in the literature that the study intends to fill. For the discussion, citations should be thoughtfully selected to compare and contrast the present study's findings with the current literature and to indicate how the present study moves the field forward.

To facilitate writing a literature review, journals are increasingly providing helpful features to guide authors. For example, the resources available through JGME include several articles on writing. 17 The journal Perspectives on Medical Education recently launched “The Writer's Craft,” which is intended to help medical educators improve their writing. Additionally, many institutions have writing centers that provide web-based materials on writing a literature review, and some even have writing coaches.

The literature review is a vital part of medical education research and should occur throughout the research process to help researchers design a strong study and effectively communicate study results and importance. To achieve these goals, researchers are advised to plan and execute the literature review carefully. The guidance in this editorial provides considerations and recommendations that may improve the quality of literature reviews.

Strengths and Weaknesses of Systematic Reviews

Automate every stage of your literature review to produce evidence-based research faster and more accurately.

Systematic reviews are considered credible sources since they are comprehensive, reproducible, and precise in stating the outcomes. The type of review system used and the approach taken depend on the goals and objectives of the research. To choose the best-suited review system, researchers must be aware of the strengths and weaknesses of each one.

Let us now look at the strengths and limitations of systematic reviews.

Strengths Of Systematic Reviews

Systematic reviews have become increasingly popular owing to their transparency, accuracy, replicability, and reduced risk of bias. Some of the main benefits of systematic reviews are;

Specificity

Researchers can answer specific research questions of high importance. For example, the efficacy of a particular drug in the treatment of an illness.

Explicit Methodology

A systematic review requires rigorous planning. Each stage of the review is predefined to the last detail. The research question is formulated using the PICO (population, intervention, comparison, and outcome) approach. A strict eligibility criteria is then established for inclusion and exclusion criteria for selecting the primary studies for the review. Every stage of the systematic review methodology is pre-specified to the last detail and made publicly available, even before starting the review process. This makes all the stages in the methodology transparent and reproducible.

Reliable And Accurate Results

The results of a systematic review are either analyzed qualitatively and presented as a textual narrative or quantitatively using statistical methods such as meta-analyses and numeric effect estimates. The quality of evidence or the confidence in effect estimates is calculated using the standardized GRADE approach.

Comprehensive And Exhaustive

A systematic review involves a thorough search of all the available data on a certain topic. It is exhaustive and considers every bit of evidence in synthesizing the outcome. Primary sources for the review are collected from databases and multiple sources, such as blogs from pharmaceutical companies, unpublished research directly from researchers, government reports, and conference proceedings. These are referred to as grey literature. The search criteria and keywords used in sourcing are specific and predefined.

Reproducible

Learn more about distillersr.

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Weaknesses Of Systematic Reviews

Although systematic reviews are robust tools in scientific research they are not immune to errors. They can be misleading, or even harmful if the data is inappropriately handled or if they are biased. Some of the limitations of systematic reviews include:

Mass Production

Due to the popularity systematic reviews have gained, they tend to be used more than required. The growth rate of systematic reviews has outpaced the growth rate of studies overall. This results in redundancy. For example, a survey published in the BMJ[1], included 73 randomly selected meta-analyses published in 2010 found that for two-thirds of these studies, there was at least one, and sometimes as many as 13, additional meta-analyses published on the same topic by early 2013.

Risk of Bias

Although systematic reviews have many advantages, they are also more susceptible to certain types of biases. A bias is a systematic or methodological error that causes misrepresentation of the study outcomes. As bias can appear at any stage, authors should be aware of the specific risks at each stage of the review process. Most of the known errors in systematic reviews arise in the selection and publication stages. The eligibility criterion in a systematic review helps to avoid selection bias. Poor study design and execution can also result in a biased outcome. It’s important to learn about the types of bias in systematic reviews .

Expressing Strong Opinions by Stealth

Selective outcome reporting is a major threat to a systematic review. The author or reviewer may decide to only report a selection of the statistically significant outcomes that suit his interest. The possibility of unfair or misleading interpretation of evidence outcomes in a systematic review can have serious implications.

Like any review system, systematic reviews have their advantages and disadvantages. Understanding them is essential to making a choice of which review system to use.

Overlapping meta-analyses on the same topic: survey of published studies. BMJ 2013; 347:f4501

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Critical Appraisal of Electronic Surveys: An Integrated Literature Review

Affiliations.

• 1 College of Nursing, Kennesaw State University, Kennesaw, GA, USA [email protected].
• 2 College of Nursing, University of Central Florida, Orlando, FL, USA.
• PMID: 37558257
• DOI: 10.1891/JNM-2021-0066

Background and Purpose: Electronic surveys are an essential data collection method in survey research but there are pros and cons. The purpose of this literature review was to understand the advantages and disadvantages of electronic surveys in research. Methods: An integrated literature review was performed. Results: Twenty publications met the criteria and were analyzed. The advantages of electronic surveys include speed, cost, convenience, flexibility, ease of analyses, global reach, reduced errors, and question diversity. The disadvantages of electronic surveys are response outcomes (nonresponse, item-nonresponse/poor completion rates, and careless responding errors) and digital literacy requirements. Conclusions: The advantages of electronic surveys outweigh their disadvantages, but researchers must understand the problems associated with electronic surveys and avoid them.

Keywords: electronic surveys; internet surveys; online surveys; survey research.

© 2023 Springer Publishing Company, LLC.

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The construction sector has experienced remarkable advancements in recent years, driven by the demand for sustainable and efficient building practices. Among these advancements, 3D concrete printing has emerged as a highly promising technology that holds the potential to revolutionize the construction industry. This review paper aims to provide a comprehensive analysis of the latest developments in three vital areas related to 3D concrete printing: sustainable materials, structural optimization, and toolpath design. A systematic literature review approach is employed based on established practices in additive manufacturing for construction to explore the intersections between these areas. The review reveals that material recycling plays a crucial role in achieving sustainable construction practices. Extensive research has been conducted on structural optimization methodologies to enhance the performance and efficiency of 3D printed concrete structures. In the printing process, toolpath design plays a significant role in ensuring the precise and efficient deposition of concrete. This paper discusses various toolpath generation strategies that take factors such as geometric complexity, printing constraints, and material flow control into account. In summary, the insights presented in this paper may serve as guidelines for researchers, engineers, and industry professionals towards sustainable and efficient construction practices using 3D concrete printing technology.

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Introduction.

Climate change has emerged as a global challenge due to the substantial carbon emissions and energy consumption. In 2022, the global carbon emissions and energy consumption reached 36.8 gigatons and 14,585 million tonnes of oil equivalent 1 , 2 , respectively. The construction sector is a major contributor to global carbon emission and energy consumption, accounting for 40% and 36% in 2022 3 , respectively. With the urban population estimated to increase to 68% by 2050, the environmental impacts of the construction sector will continuously increase 4 , underscoring the urgent need for developing sustainable construction technologies.

3D concrete printing (3DCP), also known as additive manufacturing (AM) in the construction sector 5 , offers a promising solution for achieving sustainable construction. 3DCP constructs structures by depositing printable concrete materials layer-atop-layer based on a pre-designed building model. The unique construction process possesses the advantages of enhanced sustainability and design flexibility. For example, a prefabricated bathroom unit (PBU) constructed by 3DCP achieved a reduction of 85.9% and 87.1% in carbon emissions and energy consumption, respectively, compared to that of a mold-cast counterpart 6 .

3DCP has gained much attention from both academia and engineering. Figure 1a shows the rapid growth in the publications and citations related to the keywords of “3DCP” based on data obtained from Web of Science. The number of publications reached 444 and 420 in 2022 and 2023, respectively. In these publications, several review works have been conducted in the fields of 3DCP and its potential applications 7 , 8 , 9 , 10 . Wangler et al. 8 present a technical review of 3DCP from fresh materials to hardened materials and further practical applications. Lu et al. 9 provide a comprehensive review of the material behaviors of 3DCP. However, the review articles primarily focus on the technical or material advancements of 3DCP, with less attention given to its sustainability aspects. Figure 1b illustrates the growth of publications related to the keywords of “3DCP and Sustainability”. Despite the growing interest in 3DCP, only 46 publications in 2023, approximately 10% of total 3DCP-related publications, focused on sustainability (Fig. 1a ). Among these publications, Dey et al. 11 provide a comprehensive review of the utilization of industrial wastes in printable materials to improve the sustainability of 3DCP. However, there is a lack of in-depth understanding of how to improve sustainability in 3DCP across its various construction processes.

a Keywords of “3DCP”; b keywords of “3DCP and Sustainability”.

The typical construction processes of 3DCP include the development of printable materials, structural optimization, toolpath design, and printing 12 , as shown in Fig. 2 . Each of these processes offers opportunities for enhancing sustainability. At the material level, sustainability can be improved by developing printable materials incorporated with waste materials. The waste materials are used as the substitutions of aggregate and binder contents, thereby reducing the carbon emission associated with the material extraction. At the structural level, the design of hollow structures via topology optimization (TO) 13 , 14 reduces the material usage and thus enhances sustainability. TO involves the optimization of material distribution to achieve the desired performance. In addition, the design flexibility of 3DCP is compatible with the structural TO. Finally, to implement the optimized structure into 3DCP, toolpath design methods 15 , 16 are adopted to determine the efficient path for sustainable concrete printing. The integration of sustainable printable materials, TO, and toolpath design techniques with 3DCP represents a promising synergy for future research and sustainability development in the construction sector. However, comprehensive reviews covering these three aspects are currently lacking in the existing literature.

The typical processes include the development of printable materials, structural optimization, toolpath generation, and printing.

This paper aims to fill the abovementioned research gap by providing a comprehensive review of sustainable materials, structural topology optimization, and toolpath planning for the enhancement of sustainability in 3DCP. Based on the findings of these reviewed articles, the perspectives and methods to enhance sustainability with respect to the abovementioned three aspects of 3DCP are highlighted. Finally, Section 5 conclusions are summarized and future research directions are identified.

Sustainable materials in 3D concrete printing

Integrating sustainable materials into 3DCP is a potential strategy for enhancing the sustainability of 3DCP 17 since the construction sector increasingly focuses on the recycling of natural resources, reduction in material waste and carbon emissions. The commonly developed 3D printable cementitious materials consist of binder materials (primarily cement), natural fine aggregates, additives, admixtures, and water 18 . However, two main challenges impede the development of sustainable 3D printable cementitious materials. Firstly, the high usage of ordinary Portland cement (OPC, 700–800 kg/m 3 ) 18 impacts sustainability due to the associated carbon footprint 8 . Secondly, during the printing process, most developed material mixtures only use fine aggregates for 3DCP due to the limitation of the pumping process and nozzle opening 19 , 20 .

Employing sustainable binder and aggregate alternatives is a potential solution to address these challenges 6 , 21 . This section reviews relevant advancements in adopting recycled aggregates and supplementary cementitious materials (SCMs) into 3D printable materials. Figure 3 shows the number of publications associated with the keywords “3D printed concrete”, “Recycled glass”, “Recycled sand”, “Recycled concrete aggregate”, “Recycled plastics”, “Recycled rubber”, “3D printed concrete”, “Silica fume”, “Rice husk”, “Fly ash”, “Limestone”, “Calcined clay”, “Granulated blast-furnace slag” and “Sustainable” from the Web of Science database. As shown in Fig. 3 , a growing academic interest is observed related to recycled aggregates and SCMs. The following sections discuss the performance characteristics and implications of these sustainable materials in 3DCP applications.

The literature study includes research on two main types of sustainable materials, recycled aggregates and SCM, from 2018 to 2023.

The impact of recycled aggregates, such as recycled glass 22 , concrete 23 , plastics 24 , and rubber 25 , alongside SCMs, such as silica fume 26 , rice husk ash 27 , fly ash 28 , limestone 29 , calcined clay 30 , and granulated blast-furnace slag (GGBS) 31 , on the fresh and hardened properties of 3D printable materials are analyzed. The analysis underscores the importance of these materials in advancing 3DCP sustainability but also reveals the future potential research direction to mitigate environmental impacts and foster sustainable development in 3D printable cementitious materials 19 , 32 , 33 .

3D printable material performance with recycled aggregates

The primary recycled materials in 3D printed concrete for sustainability enhancement include sand 34 , glass 22 , concrete 35 , plastics 24 , and rubber 25 . According to the data from the Hong Kong Environmental Protection Department in 2022 36 , daily waste generation in Hong Kong includes 222.6 tons of glass and 2336.9 tons of plastics. In addition, concrete and sand, derived mainly from construction and demolition debris and construction waste, account for a considerable portion of the waste, with daily production of construction waste reaching 49,865 tons 36 . In the blueprint for Hong Kong 2035 37 , the government proposes a new target concerning “Waste Reduction, Resources Circulation, Zero Landfill”, which presents a significant challenge for the recycling of waste materials in sustainable construction.

In 3DCP, it is essential to achieve a balance of fresh properties and hardened properties for printable materials. Fresh properties such as printability and pumpability, hardened properties such as strength and durability, and sustainability are critical factors for material tailoring 19 , 38 . Recycled aggregates are sustainable alternatives to natural aggregates, helping to conserve natural resources and reduce land waste from landfills 24 , 39 , 40 , 41 . This section discusses the various recycled aggregates in 3DCP (see Table 1 for details) to illustrate their impact on material fresh and hardened performance as well as sustainability.

Impacts of recycled aggregates on fresh properties

Summarizing the findings from Table 1 , the usage of recycled aggregates impacts the fresh properties of cementitious materials. The fresh properties are critical factors, which determine the printability of materials during the printing process. The printability can be characterized by workability, pumpability, extrudability, and buildability 34 . In the 3D printing process, the most essential steps are conveying mixed materials to the nozzle via a delivery system and depositing materials to build the solid object in a layer-by-layer manner 42 . In the conveying step, the materials are required to have good workability and pumpability, which indicates how easily the material can be conveyed. In addition, extrudability indicates the ability of a material to be extruded with minimal energy consumption during the delivery 43 . In the deposition step, the materials are required to have good buildability, which indicates how well the materials can be stacked stably.

With respect to workability, research has indicated that the presence of recycled sand, characterized by its high water absorption rate and irregular shape, tends to reduce the workability of concrete 44 . Similarly, incorporating recycled rubber particles with poor shape and rough surfaces has diminished the workability of 3D printed concrete, resulting in the slow relative motion of rubber particles within the concrete mixture, causing reduced processability 25 . In terms of pumpability, studies conducted by Ting et al. 45 have shown that adding recycled glass to concrete reduces its pumpability. This phenomenon can be attributed to recycled glass particles’ angular and sharp-edged nature, which obstruct flow and decrease pumpability.

Analyzing the extrudability in recycled aggregate concrete, it has been observed that the high water absorption of recycled sand necessitates the addition of extra water and superplasticizers to enhance the extrudability of 3D printed concrete 34 . In addition, the water-absorbing nature of surface cracks in recycled rubber can result in reduced extrudability. However, subjecting recycled rubber to heat treatment can partially close these surface cracks, reducing water absorption and significantly improving extrudability 46 .

Finally, with respect to buildability, increasing the substitution rate of recycled concrete aggregates has been found to improve the buildability of 3D printed concrete. Liu et al.’s 35 research suggests that the buildability increases with the rising substitution rate of recycled concrete aggregates due to the reduction in concrete density. Conversely, studies involving recycled plastics have revealed that while plastic’s hydrophobic nature enhances material flow, it also delays the hydration reaction of calcium silicate, slowing the thixotropic behavior of concrete and ultimately reducing its buildability 24 , 41 .

In summary, recycled aggregates’ influence on cementation materials’ fresh properties is multifaceted and crucial for 3D printing applications. Workability can be compromised by recycled sand and rubber, while pumpability may be hindered when using recycled glass due to its angular characteristics. Extrudability can be improved with additional water and heat treatment for specific recycled materials. In addition, buildability is positively correlated with higher substitution rates of recycled concrete aggregates, while challenges arise from the delayed hydration reaction of calcium silicate when recycled plastics are involved. These insights underscore the need for careful material selection and processing adjustments to optimize the performance of 3D printable materials.

Impacts of recycled aggregates on mechanical properties and sustainability

The mechanical performance of printed structures is paramount for ensuring their structural integrity and safety. Table 1 summarizes the mechanical properties of various types of recycled aggregates, revealing their impact on the mechanical properties of 3D printed concrete. Specifically, incorporating recycled materials such as recycled sand, coarse aggregates, glass, and plastics as sustainable alternatives in concrete leads to decreased compressive strength with increasing substitution rates 22 , 24 , 34 , 35 . This reduction in compressive strength can be attributed to the increased porosity within the concrete resulting from the addition of recycled materials, with higher porosity leading to reduced compressive strength 24 , 39 .

Beyond the problem of increased porosity, the bond between recycled aggregates and the cement matrix plays a significant role in the mechanical performance of 3D printed concrete. The smoother surface and sharper edges of recycled glass particles compared to that of natural sand particles may result in weaker bonding between the particles and the cement matrix at the interface transition zone, decreasing mechanical strength 45 . The inherent properties of recycled aggregates also impact the strength of 3D printed concrete. Recycled concrete aggregates containing old mortar and aggregates with adhering old mortar, which have lower mechanical properties, can serve as weak areas of a structure, decreasing mechanical performance 35 . On the contrary, adding cement-coated modified recycled rubber in 3D printed concrete enhances its compressive strength. This enhancement is primarily attributed to the transformation of the rubber from a hydrophobic material to a hydrophilic material after modification, promoting its interaction with the fresh mortar during mixing and resulting in a more compact interface transition zone within the structure 33 .

These findings emphasize the necessity of incorporating recycled aggregates in 3D printed concrete in appropriate amounts after considering the structural integrity and safety to achieve the desired overall properties of 3D printed concrete. As a type of sustainable material, utilizing recycled aggregates in 3DCP can reduce material costs and mitigate environmental impacts 47 . Han et al. indicate that as the proportion of recycled aggregates increases from 0% to 100%, the CO 2 emissions of 3D printed concrete decrease from 5637.647 kg to 5499.505 kg 48 . Cost analyses demonstrate a downward trend in the total cost of 3D printed concrete with the increasing proportion of recycled aggregates. For instance, the costs of 3D printed concrete with recycling proportions of 0%, 50%, and 100% are 12,913.54 CNY, 12,555.77 CNY, and 12,194.97 CNY, respectively 48 . This underscores that increasing the proportion of recycled aggregates can effectively reduce greenhouse gas emissions during concrete production and enhance building materials’ sustainability in the practical application.

3D printable material performance with supplementary cementitious materials

This section explores the impact of supplementary cementitious materials (SCMs) on the performance of 3D printable cementitious materials. In the area of 3DCP, a significant aspect is its heavy reliance on OPC compared to traditional concrete 18 . Specifically, 3D printable cementitious materials contain more than 20% of OPC, expressed by mass weight due to the requirements of printability 19 . Including SCMs in material mixtures is an alternative solution to address his problem. Various types of SCMs have been adopted for the mixture design of 3D printable concrete in the existing literature, such as fly ash, ground granulated blast furnace slag, and calcined clay from various industrial processes 49 . Fly ash, a residue from coal combustion in power plants 50 , and calcined clay, derived from high-temperature treatment of clay materials 29 , are among these industrially sourced SCM. In addition, GGBS originates from the milling process of waste slag from steel production 51 , while silica fume comes from silicon ferroalloy smelting 52 , and rice husk ash is a by-product of rice milling 27 . Incorporating these SCMs reduces the environmental burden associated with concrete production and addresses the high carbon dioxide emissions from cement production 29 , 53 .

In the selection of SCMs for 3D printable concrete, optimizing characteristics such as fresh properties, mechanical properties, durability, and sustainability is crucial 29 , 30 , 54 . These attributes directly impact the efficiency of the printing process and the performance of the final structure. Table 2 summarizes the material characteristics of individual SCM used in 3DCP and their impacts on the performance of 3D printable concrete by a systematic literature review.

Impacts of SCMs on fresh properties

Based on Table 2 , the utilization of SCMs affects the printability of 3D printed concrete. These parameters serve as crucial indicators of the stability and performance of materials during processes such as pumping, extrusion, and bearing continuous printing layer loads. In terms of workability, adding silica fume reduces the workability of 3D printed concrete. This is primarily attributed to the high surface area of silica fume, which easily aggregates with cement particles to form flocculent structures, partially hindering the free flow of water, and therefore, affecting the workability 26 , 53 .

In terms of pumpability and extrudability, the appropriate addition of fly ash and GGBS can enhance the pumpability and extrudability of cementitious materials. This is primarily attributed to the spherical and smooth surface characteristics of fly ash 55 and GGBS 56 , as shown in Table 2 , and therefore, contribute to improving the extrudability of concrete. However, excessive fly ash and GGBS may diminish extrudability due to increased water absorption. As the dosage increases, the water absorption rate rises, resulting in increased viscosity, thereby impeding the extrusion process during 3D printing 57 . The replacement of cement with silica fume 26 , rice husk ash 27 , limestone, and calcined clay 29 can enhance buildability. For example, torque viscosity rises while flow resistance and thixotropy are decreased with the rise of fly ash-to-cement ratio, negatively impacting the buildability 55 . Conversely, the influence of the silica fume-to-cement ratio shows an opposite trend on rheological properties as compared to that of the fly ash-to-cement ratio. Adding silica fume increases the filler content in concrete, strengthening the interaction between particles and thereby improving the 3D printing performance of the material 50 . Rice husk ash exhibits strong water absorption capability, reducing voids between concrete particles and promoting flocculation and hydration product formation, thereby enhancing the buildability of 3D printed concrete 27 . The addition of limestone and calcined clay can enhance the buildability due to the reduced water film thickness 30 .

In summary, incorporating SCMs significantly impacts the workability, pumpability, extrudability, and buildability of 3D printed concrete. While silica fume reduces workability due to its high surface area 26 , fly ash and GGBS can enhance pumpability and extrudability when added appropriately. However, excessive amounts may hinder extrudability due to increased water absorption 57 . Substituting cement with fly ash, silica fume, rice husk ash, limestone, and calcined clay enhances buildability 26 , 27 , 58 .

Impacts of SCMs on mechanical properties and sustainability

The mechanical performance of 3D printed concrete is crucial for construction practices. Incorporating SCMs can reduce the environmental impact and directly influence the mechanical properties of 3D printed concrete. Studies have shown that materials such as silica fume 26 , limestone, and calcined clay 29 can positively impact the mechanical properties of concrete. Silica fume acts as an inert filler in 3D printed concrete, filling voids, improving pore structure, and therefore, enhancing mechanical performance 50 . Liu et al. 26 attributed the improvement in the mechanical properties of silica fume to the fact that silica fume increases the density of the concrete, which increases the pore densities and reduces the number of connecting and oversized pores.

Moreover, the quantity of SCMs added also affects the mechanical properties of 3D printed concrete. Increasing the content of limestone and calcined clay can increase the amount of fine particles in concrete, promoting microstructure development 54 . However, small additions of fly ash and GGBS can enhance mechanical properties but excessive amounts may compromise concrete strength. This is mainly due to that the high amount of replacement of cement with fly ash or GGBS reduces the initial cement hydration at the early stage 57 . As a result, the mechanical performance of 3D printable concrete decreases. Therefore, when designing formulations for 3D printed concrete, it is essential to consider the type, quantity, and interactions of SCMs to achieve optimal mechanical performance and ensure the sustainability and durability of structures.

In 3DCP, the CO 2 emission in the material production stage is 583.1 kg CO 2 -eq/m 3 , 75% of which is contributed by the production of cement and other binder materials 18 . Therefore, using SCMs as the substitution of binder materials showed possible advantages in enhancing the environmental sustainability of 3D printable concrete 26 , 28 , 54 . Most of the reviewed studies focus on the fresh and hardened properties of 3D printable concrete with SCMs, with limited attention to the quantitative carbon emission assessment of the materials. Long et al. 59 reported that the 3D printable Limestone & Calcined clay cement composites (LC3) reduced carbon emission by 45% and energy consumption by 40%. Conversely, Yao et al. 60 reported that the carbon emission of printable materials was when geopolymer was used as the binder material. The increased carbon emission of geopolymer was due to the use of silicate (alkaline activator). Liu et al. 61 reported that the printable materials with fly ash showed less carbon emission compared to that of the printable geopolymer concrete. Different conclusions were drawn from the existing articles in terms of the carbon emission of 3D printable materials with SCM. Therefore, to comprehensively assess the sustainability effectiveness of SCMs in 3DCP, additional research is necessary in future works by conducting the quantitative carbon emission assessment.

Conventional structural topology optimization methods

Traditional design principles and considerations are being re-evaluated to leverage the unique capabilities provided by 3D printing 62 . This section aims to review the specific structural optimization methods and considerations tailored for 3DCP technology, with a particular focus on the potential to create functional, efficient, and sustainable designs using topology optimization approaches.

Structural topology optimization is the process of arranging the distribution of materials within a specified design domain to maximize specific mechanical or physical properties, while adhering to prescribed constraints. This concept arose in 1904 when Michell proposed a theoretical analysis to obtain the lightest truss 63 . The advent of finite element analysis (FEA) and the development of the widely used homogenization method 64 , 65 in the late 1980s significantly progressed this concept. Since then, the field has seen substantial advancements, thanks to methods such as Solid Isotropic Microstructure with Penalization (SIMP) 66 , Evolutionary Structural Optimization (ESO) 67 , Bi-directional Evolutionary Structural Optimization (BESO) 68 , 69 , and level set method 70 , 71 . These developments have allowed for more sophisticated and efficient designs and further expanded the possibilities of structural topology optimization. As shown in Table 3 , the various topology optimization approaches have continuously evolved to improve their effectiveness and efficiency, which are introduced individually in this section.

After the introduction of the homogenization-based topology optimization method by Bendsoe and Kikuchi 64 and later developments by Bendsoe 72 , the SIMP method was proposed 73 , 74 . Sigmund 75 provided a clear explanation of the numerical implementation of the SIMP method in 2001 using a concise 99-line Matlab code. The SIMP method assumes constant material properties for the solid material within the design domain. The design variables in the optimization process are the relative densities of each element, which range between zero and one. The material properties are modeled as the relative material density raised to a power multiplied by the properties of the solid material. During the early 1990s, Xie and Steven initially put forth the Evolutionary Structural Optimization (ESO) method to attain optimal topologies for continuum structures 67 , 76 , 77 . Subsequently, Querin et al. 68 and Yang et al. 78 advanced the ESO method to develop the Bi-directional Evolutionary Structural Optimization (BESO) method. The level set-based topology optimization method utilizes a higher-dimensional embedded function to implicitly represent solid-void interfaces 79 , 80 . In the traditional level set method, the Hamilton-Jacobi equation (PDE) is solved using the velocity normal to the interface 71 , 81 , 82 . The zero-level contour of the embedded function in the conventional level set method defines the material boundary, serving as the partition between the solid and void domains.

Advanced structural topology optimization methods

In recent years, a variety of innovative optimization algorithms have emerged to tackle the practical challenges associated with flexible design domains, smooth material boundaries, and complex fabrication constraints. One such method is the Reaction diffusion-based level set (RDLS) approach, which was initially introduced in 2014 83 . The RDLS method enables the specification of geometrical complexities within the optimal configuration, thereby facilitating the identification of the desired structure shape through the evolution of the level set function. Another notable advancement is the Floating projection topology optimization (FPTO) method, which was unveiled in 2021 84 . FPTO ensures that design variables take discrete values, resulting in more robust and practical optimization outcomes. Lastly, the Node moving-based topology optimization (NMTO) method, introduced in 2023 85 utilizes a narrowband offset from the structural profile to establish a signed-distance function, which determines the direction of node movement. NMTO aims to optimize the structural topology and enhance its overall performance by manipulating node positions. These cutting-edge methods show great promise for advancing the capabilities of 3DCP and optimizing the production of high-performance structures.

Nowadays, structural topology optimization has become increasingly popular in various fields, including additive manufacturing 69 , 86 , architectural design 87 , 88 , biochemical 89 , 90 , and aerospace engineering 91 , 92 . Among them, the high design flexibility of 3DCP makes it compatible with topology optimization to decrease material usage and improve sustainability. With the integration of these approaches and 3DCP, it becomes possible to create intricate designs that are both structurally sound and resource-efficient.

To find an appropriate method for 3DCP, the benefits and limitations of each topology optimization method should be fully understood, which are introduced and summarized in this subsection. The key scientific differences between the various topology optimization methods include mathematical formulation, optimization algorithms, material models, sensitivity analysis, and post-processing techniques.

The advantages and disadvantages of these topology optimization methods can be concluded to judge whether they can be integrated with 3DCP to fabricate efficient and environmentally friendly structures. For instance, the homogenization method allows for accurate computation of material properties using a systematic approach to obtain optimal topology. However, it may not be suitable for structures with complex material distributions and may struggle with handling geometric complexities. The SIMP method is advantageous as it provides a simple and effective way to model material properties and incorporate manufacturing constraints. Nevertheless, it produces designs with intermediate densities and may suffer from numerical instabilities. Next, the ESO method offers improved utilization of material resources by gradually removing ineffective material but may require a large number of iterations and struggle with complex geometries. Similarly, the BESO method efficiently optimizes structures by employing fundamental strategies but may produce designs with checkerboard patterns and require careful parameter tuning. On the other hand, the conventional level set method utilizes higher-dimensional embedded functions to implicitly represent solid-void interfaces accurately, which can handle topological changes during the optimization process. Nonetheless, it requires careful handling of interface tracking to avoid spurious geometries and may suffer from numerical diffusion and grid-related issues.

On the other hand, the RDLS method allows for specifying geometrical complexity but requires significant computational resources. Besides, this method is sensitive to parameter settings. The FPTO method incorporates floating projection constraints and heuristically simulates 0/1 constraints of design variables, leading to discrete and practical solutions, that provide robust optimization results by considering upper and lower bounds. However, the method’s heuristic nature may not guarantee global optimality, and it may require careful tuning of parameters to balance feasibility and optimality. The NMTO method establishes a signed-distance function to determine node-moving directions, allowing for efficient topology optimization, complex structure design, and flexibility in node manipulation. The disadvantage of the NMTO method is that it may struggle with handling complex boundary conditions and geometric constraints. These are just some general advantages and disadvantages of the topology optimization methods mentioned.

In summary, the suitability of each method regarding 3DCP depends on specific applications and requirements. Different topology optimization methods employ various mathematical formulations to represent and solve the optimization problem. Each formulation has its advantages and limitations in terms of modeling flexibility, convergence behavior, and computational efficiency. Besides, topology optimization methods may differ in the sensitivity analysis approach employed to evaluate the influence of design changes on the objective function and constraints. After obtaining an optimized design, different methods employ various post-processing techniques to interpret and convert the obtained results into manufacturable forms. These techniques can include filtering, mesh smoothing, or shape reconstruction algorithms. The selection of post-processing techniques impacts the final quality, manufacturability, and practicality of the optimized design.

Structural topology optimization in 3D concrete printing

Structural topology optimization has been widely applied in the field of 3DCP, due to the benefits to create efficient and optimized structures. By combining these two techniques, engineers can maximize the use of material, reduce weight, and enhance load-bearing capabilities, resulting in more sustainable and cost-effective structures.

The emergence of 3DCP technology has revolutionized the field of structural design by providing unprecedented freedom in creating intricate geometries and customized structures 93 . This capability opens up new opportunities for designers to push the boundaries of traditional design principles 94 , 95 . By harnessing the inherent freedom of design, 3DCP can create structures that are aesthetically appealing and optimized for performance and functionality 87 . For instance, the optimization of material distribution in 3DCP is a vital research direction to minimize material waste and optimize structural efficiency 14 , 96 . Since the last decade, structural topology optimization has been increasingly applied in 3DCP 97 , 98 . Figure 4 shows the research article number in the last decade integrating different topology optimization approaches and 3DCP using the keywords “3D printed concrete”, “Homogenization method”, “SIMP method”, “ESO method”, “BESO method”, “Level set method”, and “Phase field method” based on data obtained from the Web of Science database. This section focuses on the approaches that have been explored to achieve structural topology optimization in 3DCP. These include using additive manufacturing techniques to build complex geometries and incorporating reinforcement elements during the printing process 14 , 86 , 99 . Existing works 96 , 97 have demonstrated the ability to optimize the internal structure of concrete components, resulting in improved mechanical properties and enhanced performance.

The literature study includes research on the application of six typical optimization methods from 2014 to 2024.

The integration of topology optimization and 3DCP has the potential to enhance the performance and resource efficiency of buildings. With the increasing emphasis on sustainable and eco-friendly practices, optimized structural design has emerged as a critical strategy to reduce material usage while maintaining structural strength 99 , 100 . For instance, the varying physical properties present in functionally graded materials can be customized to meet specific requirements, all while making efficient use of material resources 101 . Building on the multi-material BESO method, a novel approach to 3DCP structural design was introduced 102 . In this approach, 3DPC components primarily experience compression without the need for extra reinforcement. Instead, they synergistically collaborate with tensioned steel cables to create an effective composite structural system. The previous study 96 examined the production process of a topology-optimized 3D printed concrete bridge structure, highlighting its significant deviation from the manufacturing procedures of conventional concrete structures. Yang et al. 103 presented an integrated design method for 3DCP by incorporating extrusion-based manufacturing characteristics into the topology optimization algorithm. Lightweight structures tend to have better seismic performance, increased durability, and reduced energy consumption compared to their heavier counterparts 61 . In addition, lighter structures require less foundation support, resulting in cost savings during construction 104 . Since construction activities are responsible for a significant amount of carbon emissions, reducing the amount of material used can significantly decrease the carbon footprint of a building.

Several examples of a combination of topology optimization and waste materials have been achieved using additive manufacturing 105 , 106 . These technologies provide benefits including minimized waste materials, accelerated construction timelines, and the capacity to create distinctive designs with intricate details. In addition, they classify large-scale 3DCP technologies, emphasizing the importance of optimizing printing ink to enhance economic and environmental results by utilizing waste materials in 3DCP applications. The combination of topology optimization and waste materials offers numerous benefits. Firstly, it promotes sustainable design practices by utilizing recycled or waste materials, contributing to the circular economy and reducing waste. Secondly, it helps reduce costs as waste materials are often less expensive or even available for free compared to conventional materials. In addition, incorporating waste materials into the design improves resource efficiency by minimizing the need for extracting and processing new materials. Moreover, the unique properties of waste materials can enhance the performance of the optimized design, such as strength, durability, or lightweight. This combination also encourages innovation and creativity by exploring unconventional design solutions.

In summary, the integration of topology optimization and 3DCP can enhance the performance and resource efficiency of buildings. The impact of structural lightweighting on seismic performance, durability, and energy consumption makes it a compulsory consideration in achieving resource efficiency. In terms of future research directions, further advancements in structural topology optimization for 3DCP are anticipated. This includes developing advanced algorithms that can handle anisotropic, large-scale optimization problems and integrating multi-material printing capabilities. In addition, research efforts could focus on exploring the potential of bio-inspired design principles and incorporating functional requirements such as interlocking, thermal insulation, and acoustic performance into the optimization process.

Toolpath design and optimization in 3D concrete printing

Toolpath design is a critical aspect of 3DCP as it directly impacts the quality, efficiency, and structural integrity of the printed components. Firstly, toolpath design takes into account material-related problems, such as the flowability and workability of the concrete mixture. By carefully planning the toolpath, engineers can ensure that the material is properly deposited, minimizing problems, such as clogging or inconsistent layering. Toolpath design also addresses process-related concerns, such as the prevention of sagging or deformation during printing. Optimizing the toolpath by the integration of factors such as load-bearing capabilities, stress distribution, and reinforcement placement, can enhance the structural integrity of the printed components.

Toolpath planning determines the success of the 3DCP process. Toolpath design involves mapping out the trajectory and deposition strategy of the printing toolhead to ensure accurate material placement and optimal structural integrity 101 , 107 , 108 . By carefully coordinating the movement of the toolhead, designers can achieve precise layering, intricate geometries, improved sustainability, and desired material properties in the printed structure. Xia et al. 109 proposed an integrated design method to improve the mechanical performance and manufacturability of material extrusion structures according to the technical characteristics of material extrusion. The technical aspects of toolpath planning encompass various considerations, such as path optimization 110 , 111 , 112 , layer sequencing 113 , 114 , manufacturing constraints 14 , 115 , 116 , and support structure generation 86 , 117 , 118 .

Figure 5 illustrates the number of publications during the past decade related to the keywords “3D printed concrete”, “Extrusion-based toolpath design”, “Geometric toolpath design”, “Toolpath visualization”, “Manufacturing constraints”, “Topology optimization-based toolpath design”, “Sliced toolpath design”, and “Toolpath design efficiency/performance” based on data obtained from the Web of Science database. Path optimization algorithms aim to minimize print time, reduce material waste, and enhance printing efficiency by optimizing the toolhead’s movement trajectory. Layer sequencing determines the order in which layers are printed to ensure stability and prevent collapse during the printing process. Material flow control involves adjusting the printing parameters, such as nozzle speed and extrusion rate, to achieve consistent material deposition and avoid defects. Lastly, support structure generation ensures the stability of overhanging or complex geometries during printing.

The literature study includes research on different toolpath design approaches from 2016 to 2024.

In recent years, there have been key research developments 14 , 15 , 96 , 119 in toolpath design and optimization. One of the key areas of focus has been on optimizing toolpaths for material efficiency and print time reduction. Researchers have explored various toolpath design methods with the instruction of topology optimization to achieve efficient and environmentally friendly structures. In addition, advancements in path optimization algorithms 110 , 111 , 112 , layer sequencing 113 , 114 , and support structure generation 86 , 117 , 118 have helped to enhance the printing efficiency and accuracy of 3DCP. Two novel printing techniques, “knitting” and “tilting” filaments, were proposed to address the anisotropy inherent in 3D printed ECC, emulating the natural crossed-lamellar structure of conch shells 120 . Three-dimensional spatial paths were devised to distribute tensile and flexural resistance in multiple directions and establish an interwoven interface system to enhance the strength of the structure.

The integration of toolpath design, 3D concrete printing, and topology optimization

Toolpath planning includes the strategic arrangement of the printing toolhead’s movement paths and deposition patterns to achieve the desired structural form 121 , 122 , 123 , 124 . This section aims to highlight the significance of toolpath planning in 3DCP and topology optimization. Existing methods for toolpath design in 3DCP involve a combination of computational algorithms, simulation techniques, and empirical knowledge. These methods consider various constraints and challenges, including printer limitations 14 , geometric complexity 16 , surface finish requirements 125 , overhang (self-support) problem 86 , interlocking 126 , and stability 127 during the printing process. They aim to generate toolpaths that maximize printing efficiency while ensuring the structural integrity and quality of the final product.

The toolpath design methods displayed in Fig. 5 can be integrated with 3DCP to fabricate efficient and high-performance structures depending on the fabrication requirements. Extrusion-based toolpath design in 3D concrete printing refers to the process of planning and creating the specific paths along which the extrusion nozzle will move to deposit layers of concrete material in a three-dimensional printed structure. Extrusion-based toolpath design 128 , 129 offers several advantages. It allows for the generation of toolpaths tailored to the specific material deposition process, resulting in efficient and optimized printing trajectories. By considering the extrusion process, this method can minimize print time, reduce material waste, and enhance printing efficiency. However, it may be limited in its ability to handle complex geometries and struggle with intricate support structure generation. Geometric toolpath design 16 , 130 focuses on creating toolpaths based on the geometric characteristics of the part being printed. This approach can lead to precise toolpaths that align with the part’s geometry, potentially reducing material waste. However, it may be less effective in optimizing toolpaths for overall printing efficiency and may struggle with handling complex layer sequencing. Toolpath visualization 131 , 132 provides a visual representation of the toolpaths, aiding in the identification of potential issues such as collisions, inefficient trajectories, or inadequate support structures. While it can help in identifying and addressing these issues, it may not actively optimize the toolpaths for print time, material waste, or printing efficiency. This method allows for precise control over layer sequencing and material flow control, ensuring stable and accurate printing. However, it may require additional computational resources and not fully optimize toolpaths for overall printing efficiency.

Toolpath design can be integrated with topology optimization to generate better performance 103 , 133 . Topology optimization-based toolpath design integrates the principles of topology optimization into the generation of toolpaths. By considering material deposition constraints and printing process dynamics, this method aims to create toolpaths that are not only geometrically optimized but also aligned with manufacturing constraints and support structure requirements. This approach can lead to highly efficient toolpaths that minimize print time, material waste, and enhance overall printing efficiency.

In summary, each of these toolpath design methods offers unique advantages and considerations. The selection of the most suitable method depends on the specific printing requirements, material characteristics, geometric complexity, and manufacturing constraints of the part being printed.

Benefits and challenges for future applications

The impact of toolpath optimization on the quality and efficiency of 3DCP has garnered significant attention. This section aims to analyze how optimized toolpaths positively influence printing quality and efficiency, emphasizing the reduction of waste and energy consumption. Advanced algorithms and computational models 119 , 127 , 134 are being developed to strategically plan the movement paths and deposition patterns of the printing toolhead, enabling precise material placement and optimized structural performance. A well-planned toolpath can result in structurally sound and aesthetically pleasing printed structures, while inadequate planning can lead to issues like material sagging, poor bonding between layers, or excessive material use 15 , 135 , 136 . Therefore, understanding and optimizing the toolpath planning process is vital for successful and reliable 3DCP 137 , 138 . Furthermore, toolpath planning also provides opportunities for customization and innovation in construction 16 , 125 . With the ability to precisely control the deposition pattern and material properties, designers can explore novel architectural forms, integrate functional features, and optimize performance characteristics.

Through systematic toolpath planning, it becomes possible to mitigate issues such as over-extrusion, uneven material distribution, and inaccuracies in layer deposition, ultimately leading to superior printing quality 112 , 139 . Moreover, the relationship between toolpath planning and material efficiency is paramount in the context of sustainable manufacturing practices. Optimized toolpaths contribute to the reduction of material waste and energy consumption by streamlining the printing process. Efficient toolpaths enable precise material deposition, minimize unnecessary movements, and optimize the use of support structures, thereby reducing material consumption and enhancing overall sustainability in 3DCP 132 , 140 , 141 .

The technical considerations involved in toolpath optimization for 3DCP encompass path optimization algorithms, print speed adjustments, and support structure generation. Path optimization algorithms aim to minimize print time and reduce material waste by optimizing the toolhead’s movement trajectory, while print speed adjustments ensure consistent material flow and deposition 132 . In addition, support structure generation and layer sequencing contribute to the stability and efficiency of the printing process 86 . Real-world case studies provide valuable insights into the benefits and challenges associated with toolpath optimization in construction projects 142 , 143 .

In terms of future research directions, there is a requirement to address additional constraints for the practical usage of 3DCP. For instance, the development of artificial intelligence empowered toolpath design methods for structures with complex geometric features. The integration of real-time monitoring and feedback systems into the toolpath design process can help improve accuracy and adaptability during printing. In addition, considering sustainability aspects, such as the use of recycled materials or minimizing waste, presents another avenue for future research in toolpath design for 3DCP.

Conclusions

This study presents a comprehensive overview of three vital aspects integrated with 3D concrete printing (3DCP) that contribute to enhancing sustainability in the construction sector. The first area of focus is sustainable material, which involves optimizing the constituents of printable materials through the recycling of waste materials into aggregates and supplementary cementitious materials. This approach reduces the environmental impact of the materials but also enhances the economic viability of 3DCP. The second vital area discussed is structural optimization, which plays a crucial role in maximizing structural performance and efficiency by rearranging material distribution. This optimization leads to improved structural integrity, reduced material usage, and minimized construction time and cost. Lastly, advances in toolpath planning have significantly improved the quality and efficiency of 3DCP. By strategically planning the movement paths and deposition patterns of the printing toolhead, toolpath optimization enhances printing accuracy, minimizes defects, and improves overall structural integrity. Furthermore, the review article also explores the influence of printing parameters on the quality and integrity of printed structures, providing valuable insights for future research and development in the field. By investigating the synergies between these three elements, this research aims to provide valuable insights for advancing sustainable and efficient building practices through the implementation of 3DCP technology.

The future of 3DCP in the construction sector is promising, while more systematic works are required to facilitate the practical application and sustainability of 3DCP:

Integration of Advanced Technologies: Future research should focus on integrating advanced technologies such as artificial intelligence and robotic control into toolpath optimization. These technologies can be adopted in the material design, system integration, and real-time optimization of printing processes.

Development of New Algorithms: There is a need for the development of new algorithms for toolpath optimization that can address specific challenges in 3DCP, such as handling complex geometries, optimizing material flow, and managing overhangs. These algorithms should also aim to optimize multiple objectives simultaneously.

Exploration of Novel Applications: Future research should explore novel applications of toolpath optimization in construction, such as printing complex architectural forms, integrating functional features, and creating customized structures. The potential of toolpath optimization in challenging environments, such as underwater or in space, should also be investigated.

Systematic literature review

This review article employs a systematic literature review approach based on established practices in additive manufacturing for construction to explore the intersections between 3DCP, material sustainability, structural topology optimization, and toolpath design. The Web of Science Core Collection, including indices such as SCI, SSCI, SCI-Expanded, and ESCI, is utilized to gather diverse publications until December 2023, encompassing journal articles, conference proceedings, books, and reports. A three-stage review method is meticulously designed to ensure objectivity and reproducibility.

Initially, relevant keywords, including “3D concrete printing,” “sustainable material,” “structural topology optimization,” and “toolpath design,” are defined to ensure a focused review. The literature reviews for sustainable material, TO, and toolpath design sections are conducted independently by different researchers. In the first stage, 1033 papers related to 3DCP are identified, with further breakdowns of 400 papers for sustainable material, 472 for structural topology optimization, and 161 for toolpath design. In the second stage, manual screening is conducted based on predefined criteria, including methodology robustness, published year, bibliographic information, and sustainability considerations. Comparative analysis results in the identification of 476 papers, comprising 245 for sustainable material, 136 for structural topology optimization, and 95 for toolpath design, as displayed in Figs. 3 , 4 , and 5 . In the third stage, the literature was further narrowed down to 160 references for inclusion in this review according to the specific criteria, including published journals, impact in the field, and number of citations. This three-step screening procedure guarantees that the literature review remains focused and relevant.

An analytical synthesis is then performed to summarize the primary studies of additive manufacturing in construction. The 160 studies obtained by the screening procedure are integrated systematically and classified into three sections according to their context, study design, and outcomes. The references cited in the sections on sustainable material, structural topology optimization, and toolpath design are 61, 76, and 23, respectively. In conclusion, the systematic literature review methodology minimizes reliance on subjective judgments, mitigates personal biases and errors, and upholds the integrity of scholarly research 144 .

Data availability

No datasets were generated or analyzed during the current study.

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Acknowledgements

This project was funded by National Science and Foundation of China (52308284), Department of Science and Technology of Guangdong Province (306071352047), and Hong Kong Polytechnic University (P0038598, P0038966, P0044299, P0045796). The funder played no role in study design, data collection, analysis and interpretation of data, or the writing of this manuscript.

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These authors contributed equally: Zicheng Zhuang, Fengming Xu, Junhong Ye.

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Department of Building and Real Estate, The Hong Kong Polytechnic University, Hong Kong, China

Zicheng Zhuang, Fengming Xu, Junhong Ye & Yiwei Weng

Department of Civil Engineering and Transportation, South China University of Technology, Hong Kong, China

Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Hong Kong, China

Liming Jiang

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Z.Z., M.X., and J.Y. conducted the review and wrote the manuscript. H.N., L.J., and Y.W. made suggestions and revised the manuscript. Y.W. provided the resources and supervision. All authors read and approved the final manuscript.

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Correspondence to Yiwei Weng .

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Zhuang, Z., Xu, F., Ye, J. et al. A comprehensive review of sustainable materials and toolpath optimization in 3D concrete printing. npj Mater. Sustain. 2 , 12 (2024). https://doi.org/10.1038/s44296-024-00017-9

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DOI : https://doi.org/10.1038/s44296-024-00017-9

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Unleashing the Power of Cloud Seeding: Navigating Potentials and Pitfalls

Since its inception in the 1940s, cloud seeding has evolved into a potential solution to droughts, a tool for firefighting, and a catalyst for weather modification. As we navigate through the promises and perils, this journey unfolds the different dimensions of cloud seeding, where advocates champion its efficacy, skeptics raise cautionary flags, and the environment holds its secrets.

Cloud Seeding Debate: Advocates, Skeptics, and the Chemical Mix

As we peer through our windows, contemplating the day’s weather forecast, the idea of influencing the skies becomes more tangible. The mysterious interaction between cloud droplets and the profound science behind weather modification have propelled cloud seeding into the spotlight – a realm both captivating and contentious. At its essence, cloud seeding ambitiously attempts to assist Mother Nature by introducing into the clouds additional “nuclei” around which water condenses, stimulating precipitation. However, this technological tool prompts intriguing questions. Could cloud seeding be a solution to drought or aid in fighting forest fires? Could increased precipitation in one area inadvertently trigger a drought elsewhere? Might cloud seeding cause excessive rain, leading to flooding? The answers aren’t straightforward, as conjuring clouds remains beyond its current scope.

The cloud seeding industry has always been a topic of debate. Advocates highlight its efficacy, with studies indicating a 10-15% increase in rainfall . Conversely, skeptics raise cautionary flags, emphasising potential hazards to public safety and the environment. Decades of research have yielded static and dynamic seeding techniques, showing indications of effectiveness by the late 1990s. 

Delving into the scientific complexities reveals two techniques: hygroscopic for warm clouds and glaciogenic for supercooled. 

Whether dispersing salt particles, such as sodium chloride (NaCl) and calcium chloride (CaCl2), in liquid clouds or triggering ice production in supercooled clouds with silver iodide (AgI), each method has a unique approach. Other chemicals used are potassium iodide (KI), sulfur dioxide (SO2), frozen carbon dioxide – dry ice (CO2), bismuth tri-iodide (BiI3), propane (C3H8), and others. 

Despite debates, silver iodide persists as the most common material, known for its efficient ice nucleating properties. However, its use raises ecological concerns because it might be toxic to terrestrial and aquatic life, prompting exploration of less harmful alternatives. Due to this, ongoing studies explore using negatively charged ions like calcium chloride instead of ice-like crystals as less harmful, but uncertainties persist. Cloud seeding can be conducted using ground-based generators, rockets, and aircraft .

How Countries Use It

As governments and private companies weigh benefits against risks, cloud seeding remains a polarising subject. While some countries embrace it for agricultural and environmental purposes, others proceed cautiously, aware of the potential consequences. 

The historical dimension of this debate resonates with events like Operation Popeye during the Vietnam War, where weather modification was a military tool. The extended monsoon season and resulting floods led to an international treaty in 1977 prohibiting the military use of weather modification. Countries like the Russian Federation and Thailand are successfully using it for suppressing heatwaves and wildfires , while the USA, China, and Australia are applying its potential for maximizing water utilization during rainfall for drought mitigation . In the United Arab Emirates, the technique is actively used to expand its agricultural capabilities and battle extreme heat . 

Private companies actively employ it, especially in hail-prone areas where insurance companies fund projects to minimise property damage. The applications span various domains, from generating rainfall for drought mitigation and enhancing snowfall at ski resorts to managing hail in agriculture. Ski resorts leverage it for intensified snowfall, hydroelectric companies use it to boost spring runoff, and it even aids in fog clearance, enhancing airport visibility. In regions like Canada’s Alberta, cloud seeding adjusts the composition of hail-producing clouds to minimise damage.

A Closer Look into Environmental Implications

Despite scientific literature seemingly giving cloud seeding a clean bill of health, there’s an undeniable air of uncertainty that beckons a closer examination. 

Consider the alluring promise of amplified precipitation through cloud seeding – an idea that, while tantalising, raises eyebrows about its lasting effects on our climate. It is important to understand that cloud seeding can only change certain clouds and does not affect the complex patterns of big-scale weather and climate events. Certainly, it helps right away with water and soil, but looking deeper suggests a complicated relationship with possible effects on local ecosystems. The prospect of increased precipitation is not without its shadows, casting doubt on unintended outcomes like the heightened risks of flooding and erosion. 

Before we wholeheartedly embrace widespread cloud seeding, a meticulous dive into scientific investigation and comprehensive research seems like a non-negotiable prerequisite. We need to ensure that the envisioned benefits of water resources do not inadvertently upset our ecology and climate stability.

Also, let us not forget air pollution – a chilling revelation that surfaces from empirical investigations into cloud seeding. 

Picture this: silver iodide particles are injected into the atmosphere, not just amping up the concentration of particulate matter but also playing the role of a trigger for other pollutants. It is a potential health mess, all while trying to control the weather. 

As we contemplate the next steps in the application of cloud seeding, there is an undeniable call for a thorough understanding of its long-term consequences for air pollution. A thoughtful and cautious approach becomes paramount, acknowledging the need for extensive research to ensure that the promised benefits don’t turn into a Faustian bargain, compromising air quality and public health.

Then, there is the scary possibility of contamination, a significant unknown in the cloud seeding process. Mishandling silver iodide and other chemicals could set off a chain reaction of environmental pollution, with consequences echoing across natural ecosystems and posing tangible risks to human health. The serious task at hand is to navigate and mitigate these contamination risks, standing as a linchpin in our overarching goal of reaping the benefits of cloud seeding without an untenable cost. This underscores the critical importance of implementing stringent protocols and precautionary measures in the handling and deployment of chemicals – our insurance policy against potential adverse effects.

Finally, let us shed light on the often-overlooked aspect of human exposure in the cloud seeding process. The environment becomes tainted, and we are abruptly confronted with the threat of iodism – a rather unpleasant combination of skin rashes and digestive issues. 

Final Thoughts

All this strongly underscores the need to strike a careful equilibrium between the alluring benefits promised by cloud seeding and the lingering health risks. As we navigate this terrain, there is an ethical imperative to conduct research that is not just exhaustive but discerning, weighing the potential benefits against the associated health risks. Before we sign off on the expansion of cloud seeding techniques, let us make sure we have done our due diligence in understanding and mitigating the repercussions of prolonged human exposure.

In the end, as governments and private companies weigh the pros and cons, the debate around cloud seeding remains as dynamic and unpredictable as the weather it aims to influence. It is not just about playing with clouds – it is about finding a delicate balance between progress and the potential pitfalls that come with tampering with nature.

Featured image: A Cessna 441 Conquest II (VH-LEM) fitted with cloud seeding equipment parked at Hobart International Airport. Credits: Wikimedia Commons

You might also like: Another Year For the Record Books: A Recap of the Main Extreme Weather Events in Summer 2023

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A Literature Review and Taxonomy of In-VR Questionnaire User Interfaces

• Safikhani, Saeed
• Nacke, Lennart
• Pirker, Johanna

Previous research demonstrates that the interruption of immersive experiences may lead to a bias in the results of questionnaires. Thus, the traditional way of presenting questionnaires, paper-based or web-based, may not be compatible with evaluating VR experiences. Recent research has shown the positive impact of embedding questionnaires contextually into the virtual environment. However, a comprehensive overview of the available VR questionnaire solutions is currently missing. Furthermore, no clear taxonomy exists for these different solutions in the literature. To address this, we present a literature review of VR questionnaire user interfaces (UI) following PRISMA guidelines. Our search returned 1.109 initial results, which were screened for eligibility, resulting in a corpus of 25 papers. This paper contributes to HCI and games research with a literature review of embedded questionnaires in VR, discussing the advantages and disadvantages and introducing a taxonomy of in-VR questionnaire UIs.

• Computer Science - Human-Computer Interaction

• DOI: 10.3390/separations11060171
• Corpus ID: 270250287

Extraction and Purification of Catechins from Tea Leaves: An Overview of Methods, Advantages, and Disadvantages

• O. Cioancă , Ionut-Iulian Lungu , +4 authors F. Crivoi
• Published in Separations 1 June 2024
• Chemistry, Medicine, Environmental Science

119 References

Insights to therapeutic potentials, pharmaceutical formulations, chemistry and analytical methods of catechin, epigallocatechin gallate for the treatment of benign and malignant gynecological diseases—focus on epigenetic mechanisms, alterations in nonvolatile components of tea (camellia sinensis) induced by insect feeding under field conditions, catechin-zinc-complex: synthesis, characterization and biological activity assessment, quantitative analysis of bioactive compounds in commercial teas: profiling catechin alkaloids, phenolic acids, and flavonols using targeted statistical approaches, wine polyphenol content during the fermentation of vitis vinifera cs grapes and its relationship with the presence of minerals in the resulting wine, green tea catechins as therapeutic antioxidants for glaucoma treatment, gut microbiota-mediated associations of green tea and catechin intakes with glucose metabolism in individuals without type 2 diabetes mellitus: a four-season observational study with mediation analysis, identification and quantification of anthocyanin and catechin compounds in purple tea leaves and flakes, a green and facile approach for fabrication of biocompatible anti-parkinson chitosan-gelatin-green tea extract composite particles with neuroprotective and neurotherapeutic effects: in vitro evaluation., related papers.

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An overview of electric vehicle load modeling strategies for grid integration studies.

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Huaman-Rivera, A.; Calloquispe-Huallpa, R.; Luna Hernandez, A.C.; Irizarry-Rivera, A. An Overview of Electric Vehicle Load Modeling Strategies for Grid Integration Studies. Electronics 2024 , 13 , 2259. https://doi.org/10.3390/electronics13122259

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Huaman-Rivera, Anny, Ricardo Calloquispe-Huallpa, Adriana C. Luna Hernandez, and Agustin Irizarry-Rivera. 2024. "An Overview of Electric Vehicle Load Modeling Strategies for Grid Integration Studies" Electronics 13, no. 12: 2259. https://doi.org/10.3390/electronics13122259

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