Continuous liquid interface production of 3D objects Tumbleston, John R.; Shirvanyants, David; Ermoshkin, Nikita ...
Science (American Association for the Advancement of Science),
03/2015, Volume:
347, Issue:
6228
Journal Article
Peer reviewed
Open access
Additive manufacturing processes such as 3D printing use time-consuming, stepwise layer-by-layer approaches to object fabrication. We demonstrate the continuous generation of monolithic polymeric ...parts up to tens of centimeters in size with feature resolution below 100 micrometers. Continuous liquid interface production is achieved with an oxygen-permeable window below the ultraviolet image projection plane, which creates a "dead zone" (persistent liquid interface) where photopolymerization is inhibited between the window and the polymerizing part. We delineate critical control parameters and show that complex solid parts can be drawn out of the resin at rates of hundreds of millimeters per hour. These print speeds allow parts to be produced in minutes instead of hours.
Three dimensional (3D) textiles are finding their way into fibre reinforced composite applications, and for good reasons; they can eliminate the hazard of delamination and enable complex ...reinforcement shapes. There is therefore a need for engineering methods to simulate these advanced textile structures during the product development phase. This is many times challenging since the textile architecture is truly 3D and not built by layers as in conventional laminated composites.
The overall approach is similar as in a method previously presented by the authors, but some steps are changed that enable modelling of textiles containing strongly curved yarns, yet with very good geometric representation. That is essential for reliable simulations of all parts of the 3D reinforced composite materials, which could then be performed at close to authentic meso level resolution.
The resulting textile geometries are very similar to the real materials they represent, both in terms of variation of yarn cross section area and shape along the length of the yarns. This is demonstrated by comparison of details between the real materials and the numerical implementations of their geometry.
A tecnologia de impressão 3D vem revolucionando muitas práticas de projeto com a possibilidade de geração de protótipos ou peças perfeitamente funcionais nas mais diversas áreas do conhecimento, tal ...como a Cartografia. Diferentes tipos de produtos cartográficos confeccionados por esses métodos produtivos podem ser encontrados na literatura. Todavia, ainda pouco é explorada a questão científica de como é este processo de produção cartográfica 3D, tampouco discutida sobre esta nova forma de abordagem de produtos cartográficos tangíveis. Neste sentido, o presente artigo apresenta os conceitos de impressão 3D aplicados à Cartografia e exemplos teórico-conceituais sobre o emprego da modelagem tridimensional aliada à manufatura aditiva na geração de produtos cartográficos. São apresentadas as vantagens da impressão 3D, tais como a visualização, o tempo de produção, uso de diferentes materiais para variados produtos, que antes eram de difícil produção, além da possibilidade de geração de novas formas de representação. São destacados elementos que ainda necessitam de maiores pesquisas, tais como a simbolização, a generalização aplicada aos modelos geométricos tridimensionais, o uso de cores na impressão 3D e de textos e toponímias.
Additive manufacturing, or 3D printing, has become significantly more commonplace in tissue engineering over the past decade, as a variety of new printing materials have been developed. In ...extrusion-based printing, materials are used for applications that range from cell free printing to cell-laden bioinks that mimic natural tissues. Beyond single tissue applications, multi-material extrusion based printing has recently been developed to manufacture scaffolds that mimic tissue interfaces. Despite these advances, some material limitations prevent wider adoption of the extrusion-based 3D printers currently available. This progress report provides an overview of this commonly used printing strategy, as well as insight into how this technique can be improved. As such, it is hoped that the prospective report guides the inclusion of more rigorous material characterization prior to printing, thereby facilitating cross-platform utilization and reproducibility.
•Explained the basic principles of structured light technologies.•Reviewed the various aspects of fringe projection techniques for 3D imaging.•Showed successes of applying fringe projection-based 3D ...imaging for scientific, industrial, and societal applications.•Presented challenging aspects through some concrete examples.•Casted our own view on the future of this field.
As one of the most popular techniques for non-contact three-dimensional (3D) sensing/imaging, fringe projection profilometry (FPP) has been growing rapidly over the past decades partially because of the improved speed of computing devices and reduced cost of hardware. 3D optical sensing has started being an integral part of our daily lives such as Face ID enabled by 3D sensors on smart phones. The impact of such techniques can be even greater with the ever-growing artificial intelligent (AI), machine learning, smart manufacturing, robotics as well as other fields. However, there are still fundamental challenges to be tackled to make such advanced optical sensing techniques ubiquitous. This paper presents the current status of FPP techniques, the major challenges still facing in the field, and our perspectives on the future of FPP techniques.
Resection and reconstruction of the chest wall can pose unique challenges given its vital role in the protection of the thoracic viscera and the dynamic part it plays in respiration. A number of new ...three‐dimensional (3D) technologies may be invaluable in tackling these challenges. Herein we review the use of 3D technologies in preoperative imaging with virtual 3D models, printing of 3D models for preoperative planning, and printing of 3D prostheses when approaching complex chest wall reconstruction.
An ideal artificial bone implant should have similar mechanical properties and biocompatibility to natural bone, as well as an internal structure that facilitates stomatal penetration. In this work, ...3D printing was used to fabricate and investigate artificial bone composites based on HA-ZrOsub.2-PVA. The composites were proportionally configured using zirconia (ZrOsub.2), hydroxyapatite (HA) and polyvinyl alcohol (PVA), where the ZrOsub.2 played a toughening role and PVA solution served as a binder. In order to obtain the optimal 3D printing process parameters for the composites, a theoretical model of the extrusion process of the composites was first established, followed by the optimization of various parameters including the spray head internal diameter, extrusion pressure, extrusion speed, and extrusion line width. The results showed that, at the optimum parameters of a spray head diameter of 0.2 mm, extrusion pressure values ranging from 1-3 bar, a line spacing of 0.8-1.5 mm, and a spray head displacement range of 8-10 mm/s, a better structure of biological bone scaffolds could be obtained. The mechanical tests performed on the scaffolds showed that the elastic modulus of the artificial bone scaffolds reached about 174 MPa, which fulfilled the biomechanical requirements of human bone. According to scanning electron microscope observation of the scaffold sample, the porosity of the scaffold sample was close to 65%, which can well promote the growth of chondrocytes and angiogenesis. In addition, c5.18 chondrocytes were used to verify the biocompatibility of the composite materials, and the cell proliferation was increased by 100% when compared with that of the control group. The results showed that the composite has good biocompatibility.
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The commercialization of sustainable 3D printing technology changed the face of manufacturing with its precise and uniform sustainable fabrication. Therefore, like other fields of ...science, research related to water treatment membranes has adopted this technology successfully, preventing the waste of huge amounts of solvents and thus reducing the high carbon emissions caused by fabrication. Currently, critical research is being conducted in relation to the membrane modules and the fabrication of the membranes themselves. The module studies focus primarily on spacer production and the membrane studies are mostly concerned with the membrane surface. The membrane surface research has successfully adapted inkjet printing for enhanced surface properties for high selectivity and fouling resistance through the printing of nano-materials on the membranes’ surfaces. Recently, 3D printing of the polymer membrane support or 3D printing-based interfacial polymerization has also been introduced into water treatment technologies. Since fouling resistance, selectivity and water permeability are the critical factors, many of the parameters can be controlled by the assistance of bespoke and precise 3D printing fabrication. In this study, we examine key aspects of technology which may shed light on future studies regarding 3D printed water treatment membranes and we review the critical developments to date.
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