Photopolymerization in 3D Printing
20 Feb 2019-Vol. 1, Iss: 4, pp 593-611
TL;DR: The field of 3D printing is continuing its rapid development in both academic and industrial research environments as mentioned in this paper, which offers flexibility over the final properties of the 3D printed materials (such as optical, chemical and mechanical properties) using versatile polymer chemistry.
Abstract: The field of 3D printing is continuing its rapid development in both academic and industrial research environments. The development of 3D printing technologies has opened new implementations in rapid prototyping, tooling, dentistry, microfluidics, biomedical devices, tissue engineering, drug delivery, etc. Among different 3D printing techniques, photopolymerization-based process (such as stereolithography and digital light processing) offers flexibility over the final properties of the 3D printed materials (such as optical, chemical, and mechanical properties) using versatile polymer chemistry. The strategy behind the 3D photopolymerization is based on using monomers/oligomers in liquid state (in the presence of photoinitiators) that can be photopolymerized (via radical or cationic mechanism) upon exposure to light source of different wavelengths (depending on the photoinitiator system). An overview of recent evolutions in the field of photopolymerization-based 3D printing and highlights of novel 3D print...
Citations
More filters
12 Aug 2021
TL;DR: In this article, the use of additive manufacturing, together with mathematical optimization techniques and innovative designs, allows the production of compact, lightweight components with greatly enhanced performance, enabling substantial weight reduction and stability enhancement, while also illustrating the transferability of the approach to experiments and devices across the quantum technology sector and beyond.
Abstract: Novel quantum technologies and devices place unprecedented demands on the performance of experimental components, while their widespread deployment beyond the laboratory necessitates increased robustness and fast, affordable production. We show how the use of additive manufacturing , together with mathematical optimization techniques and innovative designs, allows the production of compact, lightweight components with greatly enhanced performance. We use such components to produce a magneto-optical trap that captures ∼ 2 × 10 8 rubidium atoms, employing for this purpose a compact and highly stable device for spectroscopy and optical power distribution, optimized neodymium magnet arrays for magnetic field generation and a lightweight, additively manufactured ultra-high vacuum chamber. We show how the use of additive manufacturing enables substantial weight reduction and stability enhancement, while also illustrating the transferability of our approach to experiments and devices across the quantum technology sector and beyond.
8 citations
TL;DR: This review intends to provide an overview of the relevant studies on micro/nanostructured scaffolds created for soft and hard tissue regeneration and highlights their biological effects, with a particular focus on striated muscle, cartilage, and bone tissue engineering applications.
Abstract: Failure of tissues and organs resulting from degenerative diseases or trauma has caused huge economic and health concerns around the world. Tissue engineering represents the only possibility to revert this scenario owing to its potential to regenerate or replace damaged tissues and organs. In a regeneration strategy, biomaterials play a key role promoting new tissue formation by providing adequate space for cell accommodation and appropriate biochemical and biophysical cues to support cell proliferation and differentiation. Among other physical cues, the architectural features of the biomaterial as a kind of instructive stimuli can influence cellular behaviors and guide cells towards a specific tissue organization. Thus, the optimization of biomaterial micro/nano architecture, through different manufacturing techniques, is a crucial strategy for a successful regenerative therapy. Over the last decades, many micro/nanostructured biomaterials have been developed to mimic the defined structure of ECM of various soft and hard tissues. This review intends to provide an overview of the relevant studies on micro/nanostructured scaffolds created for soft and hard tissue regeneration and highlights their biological effects, with a particular focus on striated muscle, cartilage, and bone tissue engineering applications.
8 citations
TL;DR: This review focuses on the usefulness of coordination bonds to create 3D printable inks and shows how the union of chemistry and 3D technology contributes to new scientific advances, by allowing amorphous or polycrystalline solids to be transformed into objects with the desired shape for successful applications.
Abstract: This review focuses on the usefulness of coordination bonds to create 3D printable inks and shows how the union of chemistry and 3D technology contributes to new scientific advances, by allowing amorphous or polycrystalline solids to be transformed into objects with the desired shape for successful applications. The review clearly shows how there has been considerable increase in the manufacture of objects based on the combination of organic matrices and coordination compounds. These coordination compounds are usually homogeneously dispersed within the matrix, anchored onto a proper support or coating the printed object, without destroying their unique properties. Advances are so rapid that today it is already possible to 3D print objects made exclusively from coordination compounds without additives. The new printable inks are made mainly with nanoscale nonporous coordination polymers, metal-organic gels, or metal-organic frameworks. The highly dynamic coordination bond allows the creation of objects, which respond to stimuli, that can act as sensors and be used for drug delivery. In addition, the combination of metal-organic frameworks with 3D printing allows the adsorption or selective capacity of the object to be increased, relative to that of the original compound, which is useful in energy storage, gas separation, or water pollutant elimination. Furthermore, the presence of the metal ion can give them new properties, such as luminescence, that are useful for application in sensors or anticounterfeiting. Technological advances, the combination of various printing techniques, and the properties of coordination bonds lead to the creation of surprising, new, printable inks and objects with highly complex shapes that will close the gap between academia and industry for research into coordination compounds.
8 citations
TL;DR: In this paper , a 3D-printing of protein-based composite composite hydrogels and bioplastics with a range of mechanical properties is presented, which can be used for biomedical devices that degrade in situ.
Abstract: Nature uses proteins as building blocks to create three-dimensional (3D) structural components (like spiderwebs and tissue) that are recycled within a closed loop. Furthermore, it is difficult to replicate the mechanical properties of these 3D architectures within synthetic systems. In the absence of biological machinery, protein-based materials can be difficult to process and can have a limited range of mechanical properties. Herein, we present an additive manufacturing workflow to fabricate tough, protein-based composite hydrogels and bioplastics with a range of mechanical properties. Briefly, methacrylated bovine-serum-albumin-based aqueous resins were 3D-printed using a commercial vat photopolymerization system. The printed structures were then treated with tannic acid to introduce additional non-covalent interactions and form tough hydrogels. The hydrogel material could be sutured and withstand mechanical load, even after immersion in water for 24 h. Additionally, a denaturing thermal cure could be used to virtually eliminate rehydration of the material and form a bioplastic. To highlight the functionality of this material, a bioplastic screw was 3D-printed and driven into wood without damage to the screw. Moreover, the 3D-printed constructs enzymatically degraded up to 85% after 30 days in pepsin solution. Thus, these protein-based 3D-printed constructs show great potential for biomedical devices that degrade in situ.
8 citations
TL;DR: In this paper, three reentrant plate lattice structures (LSs) have been designed by transforming conventional truss-based lattices into hybrid-plate based lattices, namely, flat-plate modified auxetic (FPMA), vintile (FPV), and tesseract (FPT).
Abstract: In this work, three novel re-entrant plate lattice structures (LSs) have been designed by transforming conventional truss-based lattices into hybrid-plate based lattices, namely, flat-plate modified auxetic (FPMA), vintile (FPV), and tesseract (FPT). Additive manufacturing based on stereolithography (SLA) technology was utilized to fabricate the tensile, compressive, and LS specimens with different relative densities (ρ). The base material’s mechanical properties obtained through mechanical testing were used in a finite element-based numerical homogenization analysis to study the elastic anisotropy of the LSs. Both the FPV and FPMA showed anisotropic behavior; however, the FPT showed cubic symmetry. The universal anisotropic index was found highest for FPV and lowest for FPMA, and it followed the power-law dependence of ρ. The quasi-static compressive response of the LSs was investigated. The Gibson–Ashby power law (≈ρn) analysis revealed that the FPMA’s Young’s modulus was the highest with a mixed bending–stretching behavior (≈ρ1.30), the FPV showed a bending-dominated behavior (≈ρ3.59), and the FPT showed a stretching-dominated behavior (≈ρ1.15). Excellent mechanical properties along with superior energy absorption capabilities were observed, with the FPT showing a specific energy absorption of 4.5 J/g, surpassing most reported lattices while having a far lower density.
8 citations
References
More filters
TL;DR: The radical-mediated thiol-ene reaction has all the desirable features of a click reaction, being highly efficient, simple to execute with no side products and proceeding rapidly to high yield.
Abstract: Following Sharpless' visionary characterization of several idealized reactions as click reactions, the materials science and synthetic chemistry communities have pursued numerous routes toward the identification and implementation of these click reactions. Herein, we review the radical-mediated thiol-ene reaction as one such click reaction. This reaction has all the desirable features of a click reaction, being highly efficient, simple to execute with no side products and proceeding rapidly to high yield. Further, the thiol-ene reaction is most frequently photoinitiated, particularly for photopolymerizations resulting in highly uniform polymer networks, promoting unique capabilities related to spatial and temporal control of the click reaction. The reaction mechanism and its implementation in various synthetic methodologies, biofunctionalization, surface and polymer modification, and polymerization are all reviewed.
3,229 citations
TL;DR: The use of both synthetic and natural hydrogels as scaffolds for three-dimensional cell culture as well as synthetic hydrogel hybrids that incorporate sophisticated biochemical and mechanical cues as mimics of the native extracellular matrix are discussed.
Abstract: Methods for culturing mammalian cells ex vivo are increasingly needed to study cell and tissue physiology and to grow replacement tissue for regenerative medicine. Two-dimensional culture has been the paradigm for typical in vitro cell culture; however, it has been demonstrated that cells behave more natively when cultured in three-dimensional environments. Permissive, synthetic hydrogels and promoting, natural hydrogels have become popular as three-dimensional cell culture platforms; yet, both of these systems possess limitations. In this perspective, we discuss the use of both synthetic and natural hydrogels as scaffolds for three-dimensional cell culture as well as synthetic hydrogels that incorporate sophisticated biochemical and mechanical cues as mimics of the native extracellular matrix. Ultimately, advances in synthetic-biologic hydrogel hybrids are needed to provide robust platforms for investigating cell physiology and fabricating tissue outside of the organism.
2,298 citations
2,276 citations
TL;DR: Polymers are by far the most utilized class of materials for AM and their design, additives, and processing parameters as they relate to enhancing build speed and improving accuracy, functionality, surface finish, stability, mechanical properties, and porosity are addressed.
Abstract: Additive manufacturing (AM) alias 3D printing translates computer-aided design (CAD) virtual 3D models into physical objects. By digital slicing of CAD, 3D scan, or tomography data, AM builds objects layer by layer without the need for molds or machining. AM enables decentralized fabrication of customized objects on demand by exploiting digital information storage and retrieval via the Internet. The ongoing transition from rapid prototyping to rapid manufacturing prompts new challenges for mechanical engineers and materials scientists alike. Because polymers are by far the most utilized class of materials for AM, this Review focuses on polymer processing and the development of polymers and advanced polymer systems specifically for AM. AM techniques covered include vat photopolymerization (stereolithography), powder bed fusion (SLS), material and binder jetting (inkjet and aerosol 3D printing), sheet lamination (LOM), extrusion (FDM, 3D dispensing, 3D fiber deposition, and 3D plotting), and 3D bioprinting....
2,136 citations
TL;DR: In this paper, the authors give an overview on 3D printing techniques of polymer composite materials and the properties and performance of 3D printed composite parts as well as their potential applications in the fields of biomedical, electronics and aerospace engineering.
Abstract: The use of 3D printing for rapid tooling and manufacturing has promised to produce components with complex geometries according to computer designs. Due to the intrinsically limited mechanical properties and functionalities of printed pure polymer parts, there is a critical need to develop printable polymer composites with high performance. 3D printing offers many advantages in the fabrication of composites, including high precision, cost effective and customized geometry. This article gives an overview on 3D printing techniques of polymer composite materials and the properties and performance of 3D printed composite parts as well as their potential applications in the fields of biomedical, electronics and aerospace engineering. Common 3D printing techniques such as fused deposition modeling, selective laser sintering, inkjet 3D printing, stereolithography, and 3D plotting are introduced. The formation methodology and the performance of particle-, fiber- and nanomaterial-reinforced polymer composites are emphasized. Finally, important limitations are identified to motivate the future research of 3D printing.
2,132 citations