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oe1(光电查) - 科学论文

22 条数据
?? 中文(中国)
  • Rheological and Curing Behavior of Acrylate-Based Suspensions for the DLP 3D Printing of Complex Zirconia Parts

    摘要: The present study demonstrates the possibility of fabricating zirconia parts with a complex shape and internal architecture using a low-cost stereolithography-based technique. One of the critical steps in ceramics stereolithography is the preparation of a photo-curable slurry with properties that fulfil specific requirements, such as having a low viscosity, high solids loading and appropriate curing characteristics. Slurries with different acrylic monomers and ceramic fillers were studied concerning their rheological and curing behavior. New formulations based on mono- and tri-functional acrylic monomers revealed the following excellent rheological properties: The viscosity of the mono-/tri-acrylate-based slurry with 75 wt.% of zirconia was 1.6 Pa·s at 30 s?1. Zirconia stabilized with 3 mol.% yttria was found to be more favorable than zirconia with 8 mol.% yttria for slurry preparation, because of its lower surface area and higher tapped density. It was shown that the cure depth of the suspensions was suitable for printing objects with a 50 μm layer thickness, good interlayers connection and surface finishing.

    关键词: ceramic,digital light processing,additive manufacturing,zirconia,stereolithography

    更新于2025-09-23 15:22:29

  • From Aggregates to Porous Three-Dimensional Scaffolds through a Mechanochemical Approach to Design Photosensitive Chitosan Derivatives

    摘要: The crustacean processing industry produces large quantities of waste by-products (up to 70%). Such wastes could be used as raw materials for producing chitosan, a polysaccharide with a unique set of biochemical properties. However, the preparation methods and the long-term stability of chitosan-based products limit their application in biomedicine. In this study, different scale structures, such as aggregates, photo-crosslinked films, and 3D scaffolds based on mechanochemically-modified chitosan derivatives, were successfully formed. Dynamic light scattering revealed that aggregation of chitosan derivatives becomes more pronounced with an increase in the number of hydrophobic substituents. Although the results of the mechanical testing revealed that the plasticity of photo-crosslinked films was 5–8% higher than that for the initial chitosan films, their tensile strength remained unchanged. Different types of polymer scaffolds, such as flexible and porous ones, were developed by laser stereolithography. In vivo studies of the formed structures showed no dystrophic and necrobiotic changes, which proves their biocompatibility. Moreover, the wavelet analysis was used to show that the areas of chitosan film degradation were periodic. Comparing the results of the wavelet analysis and X-ray diffraction data, we have concluded that degradation occurs within less ordered amorphous regions in the polymer bulk.

    关键词: laser stereolithography,mechanochemical synthesis,long-term stability,tissue reaction,chitosan,scaffold

    更新于2025-09-23 15:22:29

  • Biomimetic Photocurable 3D Printed Nerve Guidance Channels with Aligned Cryomatrix Lumen for Peripheral Nerve Regeneration

    摘要: Repair and regeneration of the critically injured peripheral nerves is one of the most challenging reconstructive surgeries. Currently available and FDA approved nerve guidance channels (NGCs) are suitable for small gap injuries, and their biological performance is inferior to that of autografts. Development of biomimetic NGCs with clinically relevant geometrical and biological characteristics such as topographical, biochemical and haptotactic cues could offer better regeneration of the long gap complex nerve injuries. Here, in this study, we present the development and preclinical analysis of a 3D printed aligned cryomatrix filled NGCs along with nerve growth factor (NGF) (aCG+NGF) for peripheral nerve regeneration. We demonstrated the application of these aCG+NGF NGCs in the enhanced and successful regeneration of a critically injured rat sciatic nerve in comparison to random cryogel filled NGCs, multichannel, and clinically preferred hollow conduits as well as gold standard autografts. Our results indicated viz-a-viz similar effect of aCG+NGF NGCs to that of autografts, and not only enhanced the overall regenerated nerve physiology, but could also mimic the cellular aspects of regeneration. This study emphasizes the paradigm that these biomimetic 3D printed NGCs will lead to a better functional regenerative outcome under clinical settings.

    关键词: guidance channel,3D printing,nerve regeneration,aligned cryogel,stereolithography

    更新于2025-09-23 15:21:21

  • [IEEE 2017 21st National Biomedical Engineering Meeting (BIYOMUT) - Istanbul (2017.11.24-2017.12.26)] 2017 21st National Biomedical Engineering Meeting (BIYOMUT) - Three Dimensional Bioprinting of Tissue Engineered Artificial Heart Valves by Stereolithography

    摘要: Over the past several decades, there has been an ever-increasing demand for organ transplants. There are no significant increase observed in organ donations while the need for organ transplantation is keep increasing. Organ donation emerges as the most feasible solution especially in heart valve diseases. There are two types of artificial heart valves are utilized for heart valve replacement operations. These are mechanical heart valves and bioprosthetic heart valves. However, there are severe intrinsic problems exist for both type of artificial heart valves that are hard to be solved. Due to these reasons, growing or fabricating tissue engineered heart valves using biomaterial scaffolds with a person’s own cells with high biocompatability. The purpose of this study is; fabricating 3D artificial heart valves by stereolithography that has potential to be obtained for heart valve replacements. Stereolithography has proven potential for fabricating 3D models with high structural integrity and strong mechanical properties, yet it has not been evaluated as a bioprinter. In this study, this purpose is aimed to be succeeded.

    关键词: 3D bioprinting,artificial heart valves,stereolithography,tissue engineering

    更新于2025-09-23 15:21:21

  • [IEEE 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Design of Substrate Integrated Waveguide Based Filtering Antennas

    摘要: This paper reports the design, fabrication, and characterization of arrays of miniaturized, internally fed, polymer electrospray emitters fabricated with stereolithography. The freeform additive manufacturing process used to make the devices has associated two orders of magnitude reduction in the fabrication cost per device and fabrication time (from thousands of dollars to tens of dollars, and from months to hours, respectively) and a two orders of magnitude reduction in the cost of the manufacturing infrastructure (from millions of dollars to tens of thousands of dollars) compared with a silicon MEMS multiplexed electrospray source. The 3-D printed devices include features not easily attainable with other microfabrication methods, e.g., tapered channels and threaded holes. Through the optimization of the fabrication process 10-mm tall, isolated, straight, solid columns with diameter as small as 300 μm, and 12-mm long, straight tubes with inner diameter as small as 400 μm and wall thickness as small as 150 μm were demonstrated. Arrays with as many as 236 internally fed electrospray emitters (236 emitters in 1 cm2) were made, i.e., a twofold increase in emitter density and a sixfold increase in array size compared with the best reported values from multiplexed, internally fed, electrospray sources made of polymer. The characterization of devices with a different array size suggests a uniform emitter operation.

    关键词: electrospray,Additive manufacturing of MEMS,stereolithography,multiplexed liquid ionizers

    更新于2025-09-23 15:21:01

  • [ASME ASME 2018 13th International Manufacturing Science and Engineering Conference - College Station, Texas, USA (Monday 18 June 2018)] Volume 1: Additive Manufacturing; Bio and Sustainable Manufacturing - High-Throughput 3D Printing of Customized Imaging Lenses

    摘要: The emerging 3D printing technology has the potential to transform manufacturing customized optical elements, which currently heavily relies on the time-consuming and costly polishing and grinding processes. However, the inherent speed-accuracy trade-off seriously constraints the practical applications of 3D printing technology in optical realm. In addressing this issue, here, we report a new method featuring a significantly faster fabrication speed, at 24.54 mm3/h, without compromising the fabrication accuracy or surface finish required to 3D-print customized optical components. We demonstrated a high-speed 3D printing process with deep subwavelength (sub-10 nm) surface roughness by employing the projection micro-stereolithography process and the synergistic effects from the grayscale photopolymerization and the meniscus equilibrium post-curing methods. Fabricating a customized aspheric lens with 5 mm in height and 3 mm in diameter could be accomplished in less than four hours. The 3D-printed singlet aspheric lens demonstrated a maximal imaging resolution of 2.19 μm with low field distortion less than 0.13% across a 2-mm field of view. This work demonstrates the potential of 3D printing for rapid manufacturing of optical components.

    关键词: optical lenses,meniscus equilibrium post-curing,projection micro-stereolithography,3D printing,grayscale photopolymerization

    更新于2025-09-23 15:21:01

  • Drug-releasing Biopolymeric Structures Manufactured via Stereolithography

    摘要: Additive manufacturing (AM) techniques, such as stereolithography (SLA), enable the preparation of designed complex structures. AM has gained interest especially in the tissue engineering field due to the possibility to manufacture patient specific implants. However, AM could be useful also in controlled drug release applications, since the size and shape of the device, pore architecture and surface to volume ratio can be accurately designed. In this study, SLA was used to prepare polycaprolactone scaffold structures containing the model drug lidocaine. The release of lidocaine was studied and the influence of porosity and surface to volume ratio of structures to the drug release was analyzed. Porous samples released lidocaine faster compared to solid ones, whereas the degree of porosity and surface to volume ratio did not have a clear effect on the drug release profile.

    关键词: drug delivery,stereolithography,additive manufacturing,drug release,lidocaine,scaffold,controlled release,polycaprolactone

    更新于2025-09-23 15:21:01

  • Versatile applications of three-dimensional objects fabricated by two-photon-initiated polymerization

    摘要: In this topical review of two-photon stereolithography (TPS), we discuss novel materials and demonstrate applications of this technology. Two-photon-initiated chemical processes are used to fabricate arbitrary three-dimensional structures in TPS. In the first part of this article, the development of novel photoactive materials to fabricate pure inorganic or organic–inorganic hybrid microstructures is discussed. The second part discusses the fabrication of functional microstructures for highly specific applications to demonstrate the importance of TPS in different fields of science.

    关键词: two-photon stereolithography,photoactive materials,functional microstructures,three-dimensional structures,TPS

    更新于2025-09-23 15:21:01

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Ultralight Luminescent Solar Concentrators for Space Solar Power Systems

    摘要: This paper reports the design, fabrication, and characterization of arrays of miniaturized, internally fed, polymer electrospray emitters fabricated with stereolithography. The freeform additive manufacturing process used to make the devices has associated two orders of magnitude reduction in the fabrication cost per device and fabrication time (from thousands of dollars to tens of dollars, and from months to hours, respectively) and a two orders of magnitude reduction in the cost of the manufacturing infrastructure (from millions of dollars to tens of thousands of dollars) compared with a silicon MEMS multiplexed electrospray source. The 3-D printed devices include features not easily attainable with other microfabrication methods, e.g., tapered channels and threaded holes. Through the optimization of the fabrication process 10-mm tall, isolated, straight, solid columns with diameter as small as 300 μm, and 12-mm long, straight tubes with inner diameter as small as 400 μm and wall thickness as small as 150 μm were demonstrated. Arrays with as many as 236 internally fed electrospray emitters (236 emitters in 1 cm2) were made, i.e., a twofold increase in emitter density and a sixfold increase in array size compared with the best reported values from multiplexed, internally fed, electrospray sources made of polymer. The characterization of devices with a different array size suggests a uniform emitter operation.

    关键词: Additive manufacturing of MEMS,multiplexed liquid ionizers,electrospray,stereolithography

    更新于2025-09-23 15:19:57

  • [IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - Reducing the RF linewidth and timing jitter of a mode-locked semiconductor laser using optical feedback scheme

    摘要: This paper reports the design, fabrication, and characterization of arrays of miniaturized, internally fed, polymer electrospray emitters fabricated with stereolithography. The freeform additive manufacturing process used to make the devices has associated two orders of magnitude reduction in the fabrication cost per device and fabrication time (from thousands of dollars to tens of dollars, and from months to hours, respectively) and a two orders of magnitude reduction in the cost of the manufacturing infrastructure (from millions of dollars to tens of thousands of dollars) compared with a silicon MEMS multiplexed electrospray source. The 3-D printed devices include features not easily attainable with other microfabrication methods, e.g., tapered channels and threaded holes. Through the optimization of the fabrication process 10-mm tall, isolated, straight, solid columns with diameter as small as 300 μm, and 12-mm long, straight tubes with inner diameter as small as 400 μm and wall thickness as small as 150 μm were demonstrated. Arrays with as many as 236 internally fed electrospray emitters (236 emitters in 1 cm2) were made, i.e., a twofold increase in emitter density and a sixfold increase in array size compared with the best reported values from multiplexed, internally fed, electrospray sources made of polymer. The characterization of devices with a different array size suggests a uniform emitter operation.

    关键词: stereolithography,Additive manufacturing of MEMS,electrospray,multiplexed liquid ionizers

    更新于2025-09-23 15:19:57