Microstructures are critical elements for mechanical metamaterials design and fabrication. Tailoring the internal microscale structural pattern can achieve a much broader range of bulk properties than the constituent materials, thus enabling the metamaterial design with extraordinary properties. Studying the mechanical properties and fabricability of microstructures is critical for understanding metamaterials’ structural design and macroscale performances. This paper categorizes the commonly designed microstructures into two main classes: deterministic implicit function-based and stochastic nature-based designing strategies. The mechanical properties and 3D printability of typical instances within the two classes are studied and experimentally analyzed. Specifically, we investigate the macroscale mechanical properties (e.g., Young’s modulus, shear modulus, bulk modulus, percentage of anisotropy) of microstructures defined with triply periodic minimal surfaces (TPMS), Fourier series-based functions (FSFs), Gaussian random filed-based (GRF), and Voronoi-based microstructures. Asymptotic homogenization is exploited herein to study the macroscale properties of different microstructures, and the manufacturability of the structures is experimentally analyzed and validated on an FDM printer. We summarize the mechanical profiles and manufacturability of these microstructures defined by various principles. The resulting mechanical profiles and manufacturability of microstructures provide a reasonable basis for establishing a microstructure database and shed light on the on-demand structural units generation for metamaterial design and fabrication.
{"title":"Mechanical Profile and 3D Printability of Cellular Structures","authors":"Sina Rastegarzadeh, Samuel Muthusamy, Jida Huang","doi":"10.1115/msec2022-85541","DOIUrl":"https://doi.org/10.1115/msec2022-85541","url":null,"abstract":"\u0000 Microstructures are critical elements for mechanical metamaterials design and fabrication. Tailoring the internal microscale structural pattern can achieve a much broader range of bulk properties than the constituent materials, thus enabling the metamaterial design with extraordinary properties. Studying the mechanical properties and fabricability of microstructures is critical for understanding metamaterials’ structural design and macroscale performances. This paper categorizes the commonly designed microstructures into two main classes: deterministic implicit function-based and stochastic nature-based designing strategies. The mechanical properties and 3D printability of typical instances within the two classes are studied and experimentally analyzed. Specifically, we investigate the macroscale mechanical properties (e.g., Young’s modulus, shear modulus, bulk modulus, percentage of anisotropy) of microstructures defined with triply periodic minimal surfaces (TPMS), Fourier series-based functions (FSFs), Gaussian random filed-based (GRF), and Voronoi-based microstructures. Asymptotic homogenization is exploited herein to study the macroscale properties of different microstructures, and the manufacturability of the structures is experimentally analyzed and validated on an FDM printer. We summarize the mechanical profiles and manufacturability of these microstructures defined by various principles. The resulting mechanical profiles and manufacturability of microstructures provide a reasonable basis for establishing a microstructure database and shed light on the on-demand structural units generation for metamaterial design and fabrication.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78739276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Parts made using powder bed fusion (PBF) additive manufacturing often suffer from deformation, residual stresses, cracks, and other defects stemming from non-uniform thermal distribution during the printing process. Scan pattern (i.e., the geometric pattern of an infill) and scan sequence (i.e., the order in which features of a geometric pattern are scanned) are among the approaches that have been explored to achieve more uniform thermal distribution and reduce thermally-induced defects. The authors have recently proposed an intelligent approach (called SmartScan) for generating scan sequences. SmartScan is model-based and optimization-driven. However, it has only been applied to the most rudimentary scan patterns. This paper compares the separate and combined effects of an advanced scan pattern (the varying-helix pattern) and SmartScan on thermal distribution, part deformation, and printing time in PBF additive manufacturing. Simulations and experiments involving laser marking of AISI 316L stainless steel plates are employed for the comparison. Using SmartScan applied to a rudimentary pattern as a benchmark, the experimental results demonstrate that the application of the advanced pattern without SmartScan improved both temperature uniformity and reduced deformations by 20%, at the cost of 7% increase in printing time. The combination of the advanced pattern and SmartScan yielded 28% and 33% improvement in thermal uniformity and reduction in deformation, respectively, at the cost of 18% increase in scanning time.
{"title":"A Comparative Study on the Effects of an Advanced Scan Pattern and Intelligent Scan Sequence on Thermal Distribution, Part Deformation, and Printing Time in PBF Additive Manufacturing","authors":"Chuan He, Yueh-Lin Tsai, C. Okwudire","doi":"10.1115/msec2022-85301","DOIUrl":"https://doi.org/10.1115/msec2022-85301","url":null,"abstract":"\u0000 Parts made using powder bed fusion (PBF) additive manufacturing often suffer from deformation, residual stresses, cracks, and other defects stemming from non-uniform thermal distribution during the printing process. Scan pattern (i.e., the geometric pattern of an infill) and scan sequence (i.e., the order in which features of a geometric pattern are scanned) are among the approaches that have been explored to achieve more uniform thermal distribution and reduce thermally-induced defects. The authors have recently proposed an intelligent approach (called SmartScan) for generating scan sequences. SmartScan is model-based and optimization-driven. However, it has only been applied to the most rudimentary scan patterns. This paper compares the separate and combined effects of an advanced scan pattern (the varying-helix pattern) and SmartScan on thermal distribution, part deformation, and printing time in PBF additive manufacturing. Simulations and experiments involving laser marking of AISI 316L stainless steel plates are employed for the comparison. Using SmartScan applied to a rudimentary pattern as a benchmark, the experimental results demonstrate that the application of the advanced pattern without SmartScan improved both temperature uniformity and reduced deformations by 20%, at the cost of 7% increase in printing time. The combination of the advanced pattern and SmartScan yielded 28% and 33% improvement in thermal uniformity and reduction in deformation, respectively, at the cost of 18% increase in scanning time.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75825813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper introduces the fabrication of wafer-long nanowires using glancing angle deposition (GLAD). GLAD is an advanced physical vapor deposition technique, and it has the unique advantage of creating three-dimensional nanofeature arrays, compared to conventional top-down nanofabrication techniques. Various nanofeatures created by GLAD have been reported, including pillars, springs, chevrons, ribbons, and those structures as templates for creating nanoporous membranes; this paper fills the gap by presenting the creation of nanowires by GLAD. This paper describes the fabrication process by introducing the seeding scheme of corrals. The seed design for GLAD adopts the design rules of corrals of line seeds, and the GLAD parameters are determined by the design of the corrals of line seeds. In the experiment, conventional photolithography is used for creating micro-level widths and heights and wafer-length of line seed corrals. Two GLAD sessions with the target material for the nanowires and the mask material are deposited on the substrate in sequence with different azimuth angles; the nanowires are obtainable by anisotropic etching and removal of the sacrificial layer of corrals of line seeds. The design of the corrals of line seeds and the control of the size of the nanowires are discussed. The nanowires created are potentially applied in sensing applications, for example, the palladium or platinum nanowires can be used for hydrogen sensing.
{"title":"Fabrication of Nanowires Using Glancing Angle Deposition","authors":"C. Qu, S. Mcnamara, K. Walsh","doi":"10.1115/msec2022-83719","DOIUrl":"https://doi.org/10.1115/msec2022-83719","url":null,"abstract":"\u0000 This paper introduces the fabrication of wafer-long nanowires using glancing angle deposition (GLAD). GLAD is an advanced physical vapor deposition technique, and it has the unique advantage of creating three-dimensional nanofeature arrays, compared to conventional top-down nanofabrication techniques. Various nanofeatures created by GLAD have been reported, including pillars, springs, chevrons, ribbons, and those structures as templates for creating nanoporous membranes; this paper fills the gap by presenting the creation of nanowires by GLAD. This paper describes the fabrication process by introducing the seeding scheme of corrals. The seed design for GLAD adopts the design rules of corrals of line seeds, and the GLAD parameters are determined by the design of the corrals of line seeds. In the experiment, conventional photolithography is used for creating micro-level widths and heights and wafer-length of line seed corrals. Two GLAD sessions with the target material for the nanowires and the mask material are deposited on the substrate in sequence with different azimuth angles; the nanowires are obtainable by anisotropic etching and removal of the sacrificial layer of corrals of line seeds. The design of the corrals of line seeds and the control of the size of the nanowires are discussed. The nanowires created are potentially applied in sensing applications, for example, the palladium or platinum nanowires can be used for hydrogen sensing.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73427599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Colton Inkley, David G. Martin, Brennen Clark, N. Crane
Binder Jetting (BJ) has increased in popularity and capability since its development at MIT as it offers advantages such as fast build rates, integrated overhang support, low-power requirements, and versatility in materials. However, defects arise during layer spreading and printing that are difficult to remove during post-processing. Many of these defects are caused by particle rearrangement/ejection during binder deposition. This study explores methods of reducing particle rearrangement and ejection by applying small amounts of moisture to increase the cohesive forces between powder particles. A moisture application system was built using a piezo-electric disk to atomize water to apply a desired liquid to the BJ powder bed without disruption. The moisture is applied after spreading a new layer. Lines of binder were printed using varying droplet spacings and moisture levels. Results show that the moisture delivery system applied moisture levels across the entire application area with a standard deviation under 23%. The moisture levels delivered also had a single position test-to-test uniformity standard deviation under 21%. All tested levels of moisture addition showed mitigation of the balling defects observed in lines printed using dry powder under the same parameters. Moisture addition decreased effective saturation and increased line dimensions (height and width), but lines printed using the smallest amount of moisture tested, showed similar saturation levels and line widths to lines printed in dry powder while still partially mitigating balling.
{"title":"Controlled Wetting of Spread Powder and its Impact on Line Formation in Binder Jetting","authors":"Colton Inkley, David G. Martin, Brennen Clark, N. Crane","doi":"10.1115/msec2022-85603","DOIUrl":"https://doi.org/10.1115/msec2022-85603","url":null,"abstract":"\u0000 Binder Jetting (BJ) has increased in popularity and capability since its development at MIT as it offers advantages such as fast build rates, integrated overhang support, low-power requirements, and versatility in materials. However, defects arise during layer spreading and printing that are difficult to remove during post-processing. Many of these defects are caused by particle rearrangement/ejection during binder deposition. This study explores methods of reducing particle rearrangement and ejection by applying small amounts of moisture to increase the cohesive forces between powder particles. A moisture application system was built using a piezo-electric disk to atomize water to apply a desired liquid to the BJ powder bed without disruption. The moisture is applied after spreading a new layer. Lines of binder were printed using varying droplet spacings and moisture levels. Results show that the moisture delivery system applied moisture levels across the entire application area with a standard deviation under 23%. The moisture levels delivered also had a single position test-to-test uniformity standard deviation under 21%. All tested levels of moisture addition showed mitigation of the balling defects observed in lines printed using dry powder under the same parameters. Moisture addition decreased effective saturation and increased line dimensions (height and width), but lines printed using the smallest amount of moisture tested, showed similar saturation levels and line widths to lines printed in dry powder while still partially mitigating balling.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80153534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the physical phenomenon of the polydisperse micro-particle entrainment process from density mismatch mixture is investigated with the variation of substrate withdrawal speed. A liquid carrier system (LCS) is prepared by a polymer-based binder and an evaporating solvent. Nickel-based inorganic and spherical particles with a. moderate vol%. of 35% are added to the LCS solution. The cylindrical AISI 1006 mild steel wire substrate is dipped at different withdrawal speed ranging from 0.01 mms-1 to 20 mms-1. The binder vol%. is varied between 6.5% and 10.5%. Once the cylindrical substrate is extracted from the mixture, the surface coverage and the particle size are measured following the image analysis technique. The average particle size, coating thickness and the surface packing coverage by the particles are increasing with the higher withdrawal speed of the substrate. We observed relatively low size of particles (< 10 micrometers) as well as low surface coverage (∼33%) when the withdrawal speed remains at 0.01 mm/s. However, with high withdrawal speed (20 mm/s), we found all sizes of particles present on the substrate with a surface coverage of over 90%. The finding of this research will help to understand the high-volume solid transfer technique and develop a novel manufacturing process.
本文研究了密度错配混合物中多分散微粒夹带过程随基体提取速度变化的物理现象。用聚合物基粘结剂和蒸发溶剂制备了液体载体体系。镍基无机球形颗粒，体积%适中。的35%加入LCS溶液中以0.01 mm -1 ~ 20 mm -1的不同提取速度浸出圆柱形AISI 1006低碳钢基体。粘合剂体积%。在6.5%到10.5%之间。一旦圆柱形衬底从混合物中提取出来，根据图像分析技术测量表面覆盖率和颗粒大小。随着基体回撤速度的提高，颗粒的平均粒径、镀层厚度和表面包覆覆盖率均增大。当提取速度保持在0.01 mm/s时，我们观察到相对较小的颗粒尺寸(< 10微米)和较低的表面覆盖率(约33%)。然而，在高提取速度(20毫米/秒)下，我们发现基材上存在各种尺寸的颗粒，表面覆盖率超过90%。本研究的发现将有助于理解大体积固体转移技术，并开发一种新的制造工艺。
{"title":"Effect of Withdrawal Velocity on Particle Entrainment From Density Mismatched Mixture","authors":"S. Shovon, I. Khalil, Adeeb I. Alam, Bashir Khoda","doi":"10.1115/msec2022-85745","DOIUrl":"https://doi.org/10.1115/msec2022-85745","url":null,"abstract":"\u0000 In this work, the physical phenomenon of the polydisperse micro-particle entrainment process from density mismatch mixture is investigated with the variation of substrate withdrawal speed. A liquid carrier system (LCS) is prepared by a polymer-based binder and an evaporating solvent. Nickel-based inorganic and spherical particles with a. moderate vol%. of 35% are added to the LCS solution. The cylindrical AISI 1006 mild steel wire substrate is dipped at different withdrawal speed ranging from 0.01 mms-1 to 20 mms-1. The binder vol%. is varied between 6.5% and 10.5%. Once the cylindrical substrate is extracted from the mixture, the surface coverage and the particle size are measured following the image analysis technique. The average particle size, coating thickness and the surface packing coverage by the particles are increasing with the higher withdrawal speed of the substrate. We observed relatively low size of particles (< 10 micrometers) as well as low surface coverage (∼33%) when the withdrawal speed remains at 0.01 mm/s. However, with high withdrawal speed (20 mm/s), we found all sizes of particles present on the substrate with a surface coverage of over 90%. The finding of this research will help to understand the high-volume solid transfer technique and develop a novel manufacturing process.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91227179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Three-dimensional (3D) bioprinting is a technology that has the power to positively change the medical and pharmaceutical fields in a new and more intuitive way. The goal of this rapidly growing field is to recreate functional tissues, but the process requires the ability to achieve large full-scale scaffolds that replicate human organs. There are many challenges when attempting to print large scaffolds ensuring proper internal and external geometric fidelity that is also suitable for the living cells that undergo the printing process. In order to fabricate a larger and more structurally sound scaffold, higher material viscosities are necessary. This increase in viscosity comes with an increase in printing pressure, which can create unbearable shear stress and eventually damage cells, diminishing viability and proliferation. A set of biomaterial compositions with high structural integrity and shape fidelity that did not require harmful amounts of pressure for extrusion was identified by analyzing rheological, mechanical, and microstructural properties. Many different large-scale scaffolds maintaining geometric fidelity were fabricated with heights up to 3.0 cm and 74 layers using these hybrid hydrogels. This advancement can ensure precise internal and external geometries of full-scale functional tissue replicating scaffolds using 3D bio-printing processes that utilize pressures and materials safe for live cell viability and proliferation.
{"title":"Developing Hybrid Hydrogels for Full-Scale Scaffold Fabrication Using Extrusion-Based Bioprinting Process","authors":"Cartwright Nelson, Slesha Tuladhar, Md. Ahasan Habib","doi":"10.1115/msec2022-85372","DOIUrl":"https://doi.org/10.1115/msec2022-85372","url":null,"abstract":"\u0000 Three-dimensional (3D) bioprinting is a technology that has the power to positively change the medical and pharmaceutical fields in a new and more intuitive way. The goal of this rapidly growing field is to recreate functional tissues, but the process requires the ability to achieve large full-scale scaffolds that replicate human organs. There are many challenges when attempting to print large scaffolds ensuring proper internal and external geometric fidelity that is also suitable for the living cells that undergo the printing process. In order to fabricate a larger and more structurally sound scaffold, higher material viscosities are necessary. This increase in viscosity comes with an increase in printing pressure, which can create unbearable shear stress and eventually damage cells, diminishing viability and proliferation. A set of biomaterial compositions with high structural integrity and shape fidelity that did not require harmful amounts of pressure for extrusion was identified by analyzing rheological, mechanical, and microstructural properties. Many different large-scale scaffolds maintaining geometric fidelity were fabricated with heights up to 3.0 cm and 74 layers using these hybrid hydrogels. This advancement can ensure precise internal and external geometries of full-scale functional tissue replicating scaffolds using 3D bio-printing processes that utilize pressures and materials safe for live cell viability and proliferation.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90587467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In laser-based manufacturing, processing setup customization is one of the popular approaches used to enhance diversity in material processing using a single laser. In this study, we propose setup design modification of an ultrafast laser system to demonstrate both Tin Oxide (SnO2) nanoparticle synthesis from bulk metal, and post printing of said nanoparticles using Laser Induced Forward Transfer (LIFT) method. Using the Pulse Laser Ablation in Liquid (PLA-L) method, nanoparticles were synthesized from a bulk tin metal cube submerged in distilled water. Such nanoparticles dispersed in water can form colloidal ink that can be used for different printed electronics applications. Pulse energy was varied to investigate the influence on morphological properties of the nanoparticles. It was observed that a decrease in average particle size, and an increase in the number of particles synthesized occurred as the pulse energy was increased. In our study, we adapted the same laser system to enable LIFT operation for printing of the SnO2 nanoparticles. The colloidal ink prepared was then used in LIFT method to study feasibility of printing the synthesized nanoparticles. By varying not only the laser parameters but process parameters such as coating thickness and drying time, printed results can be improved. Experimental results show great potential for both synthesizing and printing of the nanoparticles using a single laser system. This study serves as a proof of concept that a single laser system can turn bulk metal into nanoparticles-based applications without the need for extra processing from other machines/systems, opening the door to highly customizable prints with reduced lead times.
{"title":"Synthesizing and Printing of Tin Oxide Nanoparticles Using a Single Ultrafast Laser System: A Feasibility Study","authors":"Enrique Contreras Lopez, F. Ahmed, Jianzhi Li","doi":"10.1115/msec2022-85601","DOIUrl":"https://doi.org/10.1115/msec2022-85601","url":null,"abstract":"\u0000 In laser-based manufacturing, processing setup customization is one of the popular approaches used to enhance diversity in material processing using a single laser. In this study, we propose setup design modification of an ultrafast laser system to demonstrate both Tin Oxide (SnO2) nanoparticle synthesis from bulk metal, and post printing of said nanoparticles using Laser Induced Forward Transfer (LIFT) method. Using the Pulse Laser Ablation in Liquid (PLA-L) method, nanoparticles were synthesized from a bulk tin metal cube submerged in distilled water. Such nanoparticles dispersed in water can form colloidal ink that can be used for different printed electronics applications. Pulse energy was varied to investigate the influence on morphological properties of the nanoparticles. It was observed that a decrease in average particle size, and an increase in the number of particles synthesized occurred as the pulse energy was increased. In our study, we adapted the same laser system to enable LIFT operation for printing of the SnO2 nanoparticles. The colloidal ink prepared was then used in LIFT method to study feasibility of printing the synthesized nanoparticles. By varying not only the laser parameters but process parameters such as coating thickness and drying time, printed results can be improved. Experimental results show great potential for both synthesizing and printing of the nanoparticles using a single laser system. This study serves as a proof of concept that a single laser system can turn bulk metal into nanoparticles-based applications without the need for extra processing from other machines/systems, opening the door to highly customizable prints with reduced lead times.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82793462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The overarching goal of this research work is to fabricate mechanically-robust and dimensionally-accurate dental implants for the treatment of dental fractures, anomalies, and structural deformities with a focus on oral and maxillofacial surgery applications. In pursuit of this goal, the objective of the work is to investigate the mechanical properties of several triply periodic minimal surface (TPMS) scaffolds, composed of a medical-grade photopolymer resin, fabricated using digital light processing (DLP) process. DLP is a vat-photopolymerization additive manufacturing process; it has emerged as a high-resolution method for the fabrication of a broad spectrum of biological tissues and constructs for tissue engineering applications. However, the DLP process is intrinsically complex; the complexity of the process stems from complex physiochemical phenomena (such as UV light photopolymerization) as well as resin (photopolymer)-process interactions, which may adversely influence the mechanical properties, the surface morphology, and ultimately the functional characteristics of fabricated dental scaffolds. Consequently, physics-based process and material characterization would be an inevitable need. In this study, several TPMS scaffolds (having complex internal geometries) were fabricated, based on a medical-grade photopolymer resin. The compression properties of the fabricated dental scaffolds were measured using a compression testing machine. In addition, the bioactivity of the scaffolds was assessed in a simulated body fluid (SBF). The outcomes of this study pave the way for the fabrication of complex dental implants with tunable medical and functional properties.
{"title":"Experimental Characterization of the Mechanical Properties of Medical-Grade Dental Implants, Fabricated Using Vat-Photopolymerization Additive Manufacturing Process","authors":"Regan Raines, James B. Day, Roozbeh Salary","doi":"10.1115/msec2022-85436","DOIUrl":"https://doi.org/10.1115/msec2022-85436","url":null,"abstract":"\u0000 The overarching goal of this research work is to fabricate mechanically-robust and dimensionally-accurate dental implants for the treatment of dental fractures, anomalies, and structural deformities with a focus on oral and maxillofacial surgery applications. In pursuit of this goal, the objective of the work is to investigate the mechanical properties of several triply periodic minimal surface (TPMS) scaffolds, composed of a medical-grade photopolymer resin, fabricated using digital light processing (DLP) process. DLP is a vat-photopolymerization additive manufacturing process; it has emerged as a high-resolution method for the fabrication of a broad spectrum of biological tissues and constructs for tissue engineering applications. However, the DLP process is intrinsically complex; the complexity of the process stems from complex physiochemical phenomena (such as UV light photopolymerization) as well as resin (photopolymer)-process interactions, which may adversely influence the mechanical properties, the surface morphology, and ultimately the functional characteristics of fabricated dental scaffolds. Consequently, physics-based process and material characterization would be an inevitable need. In this study, several TPMS scaffolds (having complex internal geometries) were fabricated, based on a medical-grade photopolymer resin. The compression properties of the fabricated dental scaffolds were measured using a compression testing machine. In addition, the bioactivity of the scaffolds was assessed in a simulated body fluid (SBF). The outcomes of this study pave the way for the fabrication of complex dental implants with tunable medical and functional properties.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87735747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Permanent settlement on the surface of planets like the Moon and Mars is anticipated to be beneficial for long-duration exploration missions. The space agencies have developed several plans, along with other commercial partners, to build operational stations on such planetary bodies, which will be economical and resourceful to execute further missions into deep space. Therefore, the real integration of an advanced manufacturing technique is essentially a matter of further research to design and deliver critical subsystems utilising in-situ resources available on the surface of Mars. The Additive Manufacturing (AM) technique is becoming increasingly promising for developing complex structures by depositing multiple consecutive layers, unlike specific moulds required in the conventional manufacturing process. Therefore, to assess the feasibility of 3D printing with local resources technically, a recently developed artificial Mars soil simulant known as Jining Martian Soil Simulant (JMSS-1) has been processed to formulate clay useful for the extrusion 3D printing process. The developed Martian clay has been fabricated, characterised, and its dielectric properties measured at high frequencies for the first time. A stable aqueous clay has been developed containing less organics (< 10 wt% versus typically 30–40 wt%), which is amenable to resource-efficient 3D printing. A range of solid and porous structures of various shapes and sizes have been fabricated using a custom-developed material extrusion 3D printing system. The 3D printed artificial Martian clay sintered for 2 hours at 1100°C exhibited relative permittivity (εr) = 4.52, dielectric loss (tanδ) = 0.0015, quality factor (Q × f) = 7039 GHz. TCf = −19; and demonstrated similar properties at higher frequencies. This work demonstrates the progress in clay additive manufacturing and illustrates the potential to deliver components with functional properties through a “Powder to Product” holistic approach that can support long-term space exploration by utilising local resources available on Mars.
{"title":"3D Printing of Eco-Friendly Artificial Martian Clay (JMSS-1) for In-Situ Resource Utilization on Mars","authors":"Avishek Ghosh, J. Favier","doi":"10.1115/msec2022-85353","DOIUrl":"https://doi.org/10.1115/msec2022-85353","url":null,"abstract":"\u0000 Permanent settlement on the surface of planets like the Moon and Mars is anticipated to be beneficial for long-duration exploration missions. The space agencies have developed several plans, along with other commercial partners, to build operational stations on such planetary bodies, which will be economical and resourceful to execute further missions into deep space. Therefore, the real integration of an advanced manufacturing technique is essentially a matter of further research to design and deliver critical subsystems utilising in-situ resources available on the surface of Mars. The Additive Manufacturing (AM) technique is becoming increasingly promising for developing complex structures by depositing multiple consecutive layers, unlike specific moulds required in the conventional manufacturing process. Therefore, to assess the feasibility of 3D printing with local resources technically, a recently developed artificial Mars soil simulant known as Jining Martian Soil Simulant (JMSS-1) has been processed to formulate clay useful for the extrusion 3D printing process. The developed Martian clay has been fabricated, characterised, and its dielectric properties measured at high frequencies for the first time. A stable aqueous clay has been developed containing less organics (< 10 wt% versus typically 30–40 wt%), which is amenable to resource-efficient 3D printing. A range of solid and porous structures of various shapes and sizes have been fabricated using a custom-developed material extrusion 3D printing system. The 3D printed artificial Martian clay sintered for 2 hours at 1100°C exhibited relative permittivity (εr) = 4.52, dielectric loss (tanδ) = 0.0015, quality factor (Q × f) = 7039 GHz. TCf = −19; and demonstrated similar properties at higher frequencies. This work demonstrates the progress in clay additive manufacturing and illustrates the potential to deliver components with functional properties through a “Powder to Product” holistic approach that can support long-term space exploration by utilising local resources available on Mars.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90881680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Direct write Inkjet Printing is a versatile additive manufacturing technology that allows for the fabrication of multiscale structures with dimensions spanning from nano to cm scale. This is made possible due to the development of novel dispensing tools, enabling controlled and precise deposition of fluid with a wide range of viscosities (1 – 50 000 mPas) in nanoliter volumes. As a result, Inkjet printing has been recognized as a potential low-cost alternative for several established manufacturing methods, including cleanroom fabrication. In this paper, we present a characterization study of PEDOT: PSS polymer ink deposition printing process realized with the help of an automated, custom Direct Write Inkjet system. PEDOT: PSS is a highly conductive ink that possesses good film forming capabilities. Applications thus include printing thin films on flexible substrates for tactile (touch) sensors. We applied the Taguchi Design of Experiment (DOE) method to produce the optimal set of PEDOT:PSS ink dispensing parameters, to study their influence on the resulting ink droplet diameter. We experimentally determined that the desired outcome of a printed thin film with minimum thickness is directly related to 1) the minimum volume of dispensed fluid and 2) the presence of a preprocessing step, namely air plasma treatment of the Kapton substrate. Results show that an ink deposit with a minimum diameter of 482 μm, and a thin film with approximately 300 nm thickness were produced with good repeatability.
{"title":"Characterization of the Direct Write Inkjet Printing Process for Automated Fabrication of PEDOT: PSS Thin Films","authors":"Sara Morice, A. Sherehiy, Danming Wei, D. Popa","doi":"10.1115/msec2022-85409","DOIUrl":"https://doi.org/10.1115/msec2022-85409","url":null,"abstract":"\u0000 Direct write Inkjet Printing is a versatile additive manufacturing technology that allows for the fabrication of multiscale structures with dimensions spanning from nano to cm scale. This is made possible due to the development of novel dispensing tools, enabling controlled and precise deposition of fluid with a wide range of viscosities (1 – 50 000 mPas) in nanoliter volumes. As a result, Inkjet printing has been recognized as a potential low-cost alternative for several established manufacturing methods, including cleanroom fabrication. In this paper, we present a characterization study of PEDOT: PSS polymer ink deposition printing process realized with the help of an automated, custom Direct Write Inkjet system. PEDOT: PSS is a highly conductive ink that possesses good film forming capabilities. Applications thus include printing thin films on flexible substrates for tactile (touch) sensors. We applied the Taguchi Design of Experiment (DOE) method to produce the optimal set of PEDOT:PSS ink dispensing parameters, to study their influence on the resulting ink droplet diameter. We experimentally determined that the desired outcome of a printed thin film with minimum thickness is directly related to 1) the minimum volume of dispensed fluid and 2) the presence of a preprocessing step, namely air plasma treatment of the Kapton substrate. Results show that an ink deposit with a minimum diameter of 482 μm, and a thin film with approximately 300 nm thickness were produced with good repeatability.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81723610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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