Search results

Liquid crystal display (LCD)-based stereolithography (SLA) technique has been used in drug delivery and fabrication of microfluidic devices and piezoelectric materials. It is an additive manufacturing technique where an LCD source has been used as a mask to project the image onto the tank filled with photo curable resin. This resin, when interacted with light, becomes solid. However, critical information regarding the energy absorption during the compression analysis of different components three-dimensional (3D) printed by SLA process is still limited. Therefore, this study aims to investigate the effect of different process parameters on the compressive properties.

In the present study, the influence of layer thickness, infill density and build orientation on the compression properties is investigated. Four infill densities, that is, 20%, 40%, 60% and 80%; five-layer thicknesses, that is, 50 µm, 75 µm, 100 µm, 150 µm and 200 µm; and two different orientations, that is, YXZ and ZXY, have been selected for this study.

It is observed that the samples printed with acrylonitrile butadiene styrene (ABS) absorbed higher energy than the flexible polyurethane (FPU). Higher infill density and sample oriented on ZXY absorbed higher energy than sample printed on YXZ orientation, in both the ABS and FPU materials. Parts printed with 80% infill density and 200 µm layer thickness resulted into maximum energy for both the materials.

In this study, two different types of materials are used for the compression analysis using LCD-SLA-based 3D printer. Specific energy absorbed by the samples during compression testing is measured to compare the influence of parameters. The investigation of infill parameters particularly the infill density is very limited for the SLA-based 3D printing process. Also, the results of this study provide a database to select the print parameters to obtain the required properties. The results also compare the specific energy for hard and flexible material for the same combination of the process parameters.

Although many researchers have widely studied additive manufacturing (AM) as one of the most important industrial revolutions, few have presented a bibliometric analysis of the published studies in this area. This paper aims to evaluate AM research trends based on 4607 publications most cited from year 2010 to 2020.

The research methodology is bibliometric indicators and network analysis, including analysis based on keywords, citation analysis, productive journal, related published papers and authors indicators. Two free available software were employed VOSviewer and Bibexcel.

Keywords analysis results indicate that among the AM processes, Selective Laser Melting and Fused Deposition Modeling techniques, are the two processes ranked on top of the techniques employed and studied with 35.76% and 20.09% respectively. The citation analysis by VOSviewer software, reveals that the medical applications field and the fabrication of metal parts are the areas that interest researchers greatly. Different new research niches, as pharmaceutical industry, digital construction and food fabrication are growing topics in AM scientific works. This study reveals that journals “Materials & design”, “Advanced materials”, “Acs applied materials & interfaces”, “Additive manufacturing”, “Advanced functional materials” and “Biofabrication” are the most productive and influential in AM scientific research.

The results and conclusions of this work can be used as indicators of trends in AM research and/or as prospects for future studies in this area.

Because of the significant differences in the features and requirements of specific products and the capabilities of various additive manufacturing (AM) solutions, selecting the most appropriate AM technology can be challenging. This study aims to propose a method to solve the complex process selection in 3D printing applications, especially by creating a new multicriteria decision-making tool that takes the direct certainty of each comparison to reflect the decision-maker’s desire effectively.

The methodology proposed includes five steps: defining the AM technology selection decision criteria and constraints, extracting available AM parameters from the database, evaluating the selected AM technology parameters based on the proposed decision-making methodology, improving the accuracy of the decision by adopting newly proposed weighting scheme and selecting optimal AM technologies by integrating information gathered from the whole decision-making process.

To demonstrate the feasibility and reliability of the proposed methodology, this case study describes a detailed industrial application in rapid investment casting that applies the weightings to a tailored AM technologies and materials database to determine the most suitable AM process. The results showed that the proposed methodology could solve complicated AM process selection problems at both the design and manufacturing stages.

This research proposes a unique multicriteria decision-making solution, which employs an exclusive weightings calculation algorithm that converts the decision-maker's subjective priority of the involved criteria into comparable values. The proposed framework can reduce decision-maker's comparison duty and potentially reduce errors in the pairwise comparisons used in other decision-making methodologies.

This paper aims to present a multi-material additive manufacturing (AM) process with a newly developed curing-on-demand method to fabricate a three-dimensional (3D) object with multiple material compositions.

Unlike the deposition-on-demand printing method, the proposed curing-on-demand printheads use a digital light processing (DLP) projector to selectively cure a thin layer of liquid photocurable resin and then clean the residual uncured material effectively using a vacuuming and post-curing device. Each printhead can individually fabricate one type of material using digitally controlled mask image patterns. The proposed AM process can accurately deposit multiple materials in each layer by combining multiple curing-on-demand printheads together. Consequently, a three-dimensional object can be fabricated layer-by-layer using the developed curing-on-demand printing method.

Effective cleaning of uncured resin is realized with reduced coated resin whose height is in the sub-millimeter level and improved vacuum cleaning performance with the uncleaned resin less than 10 µm thick. Also, fast material swapping is achieved using the compact design of multiple printheads.

The proposed multi-material stereolithography (SL) process enables 3D printing components using more viscous materials and can achieve desired manufacturing characteristics, including high feature resolution, fast fabrication speed and low machine cost.

Three-dimensional printing of acrylic-based medical devices is projected to grow exponentially despite the limitations of photopolymerization and the lack of information on the clinical performance of the materials. The purpose of this paper is to address an issue of critical importance in the translation of the three-dimensionally printed structures to the clinic, which is assessing the toxicity of the polymers and their precursors.

This review highlights the different manufacturing processes, challenges and novel experimental work including the zebrafish embryo model, which offers a potential method for toxicity profiling of biomedical photopolymers and their precursors due to its high genetic similarity to humans.

Materials information and experimental data available so far suggest that there is a need for regular and rigorous evaluation of new materials to establish their safety and protect users engaging in biomedically-related printing activities.

The review identifies stringent, contemporary and cost-effective analytical methods for assessing the safety of biomedical photopolymers and their precursors.

Additive manufacturing (AM) technology has a huge influence on the real world because of its ability to manufacture massively complicated geometrics. The purpose of this study is to use CiteSpace (CS) visual analysis to identify fused deposition modeling (FDM) research and development patterns to guide researchers to decide future research and provide a framework for corporations and organizations to prepare for the development in the rapid prototyping industry. Three-dimensional printing (3DP) is defined to budget minimize manufactured input and output for aviation and the medical product industrial sectors. 3DP has implemented its potential in the Coronavirus Disease of 2019 (COVID-19) reaction.

First, 396 original publications were extracted from the web of science (WOS) with the comprehensive list and did scientometrics analysis in CS software. The parameters are specified in CS including the span (from 2011 to 2019, one year slice for the co-authorship and the co-accordance analysis), visualization (show the merged networks), specific criteria for selection (top 20%), node form (author, organization, region, reference cited; cited author, journal and keywords) and pruning (pathfinder and slicing network). Finally, correlating data was studied and showed the results of the visualization study of FDM research were shown.

The framework of FDM information is beginning to take shape. About hot research topics, there are “Morphology,” “Tensile Property by making Blends,” “Use of Carbon nanotube in 3DP” and “Topology optimization.” Regarding the latest research frontiers of FDM printing, there are “Fused Filament Fabrication,” “AM,” in FDM printing. Where “Post-processing” and “environmental impact” are the research hotspots in FDM printing. These research results can provide insight into FDM printing and useful information to consider the existing studies and developments in FDM researchers’ analysis.

Despite some important obtained results through FDM-related publications’ visualization, some deficiencies remain in this research. With >99% of articles written in English, the input data for CS was all downloaded from WOS databases, resulting in a language bias of papers in other languages and neglecting other data sources. Although, there are several challenges being faced by the FDM that limit its wide variety of applications. However, the significance of the current work concerning the technical and engineering prospects is discussed herein.

First, the novelty of this work lies in describing the FDM approach in a Scientometric way. In Scientometric investigation, leading writers, organizations, keywords, hot research and emerging knowledge points were explained. Second, this research has thoroughly and comprehensively examined the useful sustainability effects, i.e. economic sustainability, energy-based sustainability, environmental sustainability, of 3DP in industrial development in qualitative and quantitative aspects by 2025 from a global viewpoint. Third, this work also described the practical significance of FDM based on 3DP since COVID-19. 3DP has stepped up as a vital technology to support improved healthcare and other general response to emergency situations.

The purpose of this paper is to propose and demonstrate a new additive manufacturing approach that breaks the layer-based point scanning limitations to increase fabrication speed, obtain better surface finish, achieve material flexibility and reduce equipment costs.

The freeform additive manufacturing approach conceptually views a 3D article as an assembly of freeform elements distributed spatially following a flexible 3D assembly structure, which conforms to the surface of the article and physically builds the article by sequentially forming the freeform elements by a vari-directional vari-dimensional capable material deposition mechanism. Vari-directional building along tangential directions of part surface gives surface smoothness. Vari-dimensional deposition maximizes material output to increase build rate wherever allowed and minimizes deposition sizes for resolution whenever needed.

Process steps based on geometric and data processing considerations were described. Dispensing and forming of basic vari-directional and vari-dimensional freeform elements and basic operations of joining them were developed using thermoplastics. Forming of 3D articles at build rates of 2-5 times the fused deposition modeling (FDM) rate was demonstrated and improvement over ten times was shown to be feasible. FDM compatible operations using 0.7 mm wire depositions from a variable exit-dispensing unit were demonstrated. Preliminary tests of a surface finishing process showed a result of 0.8-1.9 um Ra. Initial results of dispensing wax, tin alloy and steel were also shown.

This is the first time that both vari-directional and vari-dimensional material depositions are combined in a new freeform building method, which has potential impact on the FDM and other additive manufacturing methods.

Retailing thought and practice is premised on the assumption that consumers visit retailers to search for and acquire objects produced by manufacturers. In essence, we assume that the acts of consuming and producing are conducted by separate entities. This unspoken yet familiar premise shapes the questions retail scholars ask and the way retail practitioners think about their industry. Although this assumption accurately depicted retailing since the Industrial Revolution, its relevance is being challenged by a growing set of individuals who are equipped with new digital tools to engage in self-manufacturing. In this chapter, we examine self-manufacturing with a particular focus on the recent rise of desktop 3D printing. After discussing this new technology and reviewing the literature, we offer a conceptual classification of four distinct types of 3D printed objects and use this classification to inform a content analysis of over 400 of these objects. Based on this review and analysis, we discuss the implications of self-manufacturing for retailing thought and practice.

In the past decade, three-dimensional (3D) printing has gained attention in areas such as medicine, engineering, manufacturing art and most recently in education. In biomedical, the development of a wide range of biomaterials has catalysed the considerable role of 3D printing (3DP), where it functions as synthetic frameworks in the form of scaffolds, constructs or matrices. The purpose of this paper is to present the state-of-the-art literature coverage of 3DP applications in tissue engineering (such as customized scaffoldings and organs, and regenerative medicine).

This review focusses on various 3DP techniques and biomaterials for tissue engineering (TE) applications. The literature reviewed in the manuscript has been collected from various journal search engines including Google Scholar, Research Gate, Academia, PubMed, Scopus, EMBASE, Cochrane Library and Web of Science. The keywords that have been selected for the searches were 3 D printing, tissue engineering, scaffoldings, organs, regenerative medicine, biomaterials, standards, applications and future directions. Further, the sub-classifications of the keyword, wherever possible, have been used as sectioned/sub-sectioned in the manuscript.

3DP techniques have many applications in biomedical and TE (B-TE), as covered in the literature. Customized structures for B-TE applications are easy and cost-effective to manufacture through 3DP, whereas on many occasions, conventional technologies generally become incompatible. For this, this new class of manufacturing must be explored to further capabilities for many potential applications.

This review paper presents a comprehensive study of the various types of 3DP technologies in the light of their possible B-TE application as well as provides a future roadmap.