Advancements of additive manufacturing enable fabrication of in vitro biomimetic grafts leveraging biological materials and cells for various biomedical applications. The realization of such biofabrication typically requires time from minutes to hours depending on the scale and complexity of the models. During direct biofabrication, cell sedimentation with the resultant aggregation is extensively deemed to be one of the acute problems for precise and reliable inkjet-based bioprinting. It often results in highly unstable droplet formation, nozzle clogging, and non-uniformity of post-printing cell distribution. Our previous study has implemented active bioink circulation to mitigate cell sedimentation and aggregation within the bioink reservoir. This study focuses on the comparison of post-printing cell distribution within formed microspheres and one-layer sheets with and without active circulation. The experimental results have demonstrated the significant improvement in post-printing cell distribution under implemented active circulation. Moreover, the printed sheet samples are subject to 3-day incubation to investigate the effect of cell distribution on cell viability and proliferation. It shows that compared to non-uniform cell distribution the uniform cell distribution significantly improves cell viability (92% vs 77% at Day 3) and cell proliferation (3.3 times vs 1.7 times at Day 3). The preliminary results in this letter have demonstrated not only the high effectiveness of the active bioink circulation to improve post-printing cell distribution within microspheres and one-layer sheets, but also the critical role of the uniform post-printing cell distribution in promoting cell viability and proliferation.
{"title":"Improving Uniformity of Cell Distribution in Post-Inkjet-Based Bioprinting","authors":"Jiachen Liu, Changxue Xu","doi":"10.1115/1.4063134","DOIUrl":"https://doi.org/10.1115/1.4063134","url":null,"abstract":"\u0000 Advancements of additive manufacturing enable fabrication of in vitro biomimetic grafts leveraging biological materials and cells for various biomedical applications. The realization of such biofabrication typically requires time from minutes to hours depending on the scale and complexity of the models. During direct biofabrication, cell sedimentation with the resultant aggregation is extensively deemed to be one of the acute problems for precise and reliable inkjet-based bioprinting. It often results in highly unstable droplet formation, nozzle clogging, and non-uniformity of post-printing cell distribution. Our previous study has implemented active bioink circulation to mitigate cell sedimentation and aggregation within the bioink reservoir. This study focuses on the comparison of post-printing cell distribution within formed microspheres and one-layer sheets with and without active circulation. The experimental results have demonstrated the significant improvement in post-printing cell distribution under implemented active circulation. Moreover, the printed sheet samples are subject to 3-day incubation to investigate the effect of cell distribution on cell viability and proliferation. It shows that compared to non-uniform cell distribution the uniform cell distribution significantly improves cell viability (92% vs 77% at Day 3) and cell proliferation (3.3 times vs 1.7 times at Day 3). The preliminary results in this letter have demonstrated not only the high effectiveness of the active bioink circulation to improve post-printing cell distribution within microspheres and one-layer sheets, but also the critical role of the uniform post-printing cell distribution in promoting cell viability and proliferation.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43160196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laurent Terrenoir, J. Lartigau, A. Arjunan, Laura Laguna Salvadó, Christophe Merlo
Wire Arc Additive Manufacturing (WAAM) enables 3D printing of large high-value metal components. However, integrating WAAM into production lines requires a critical understanding of the influence of process parameters on the resulting material characteristics. As such, this research investigates the relationship between WAAM wire feed speed (WFS) and torch speed (TS) on the resulting mechanical characteristics of 316LSi thick parts (2.5 cm - 0.98 in). The experimental procedure is informed by a training matrix that allows parametric analysis of WFS and TS on the ultimate tensile strength (σult), yield strength (σy), elastic modulus (E), failure strain (εf), hardness (HV0.5) and dimensional accuracy (Da) of the printed samples. The research found that WAAM-processed 316LSi parts feature isotropic material properties despite variations in WFS and TS. The developed surrogate model offers five significant polynomial models capable of accurately predicting the influence of WAAM process parameters on σult, σy, εf, E and Da. The research found TS to be the most significant WAAM process parameter in comparison to WFS for σult and εy. On the contrary σy, E and Da were found to be primarily driven by WFS as opposed to TS. Overall, the paper for the first time presents an accurate surrogate model to predict the mechanical characteristics of WAAM 316LSi thick parts informed by wire feed speed and torch speed. The study demonstrates that the mechanical properties of WAAM-processed steel are primarily influenced by the underlying process parameters offering significant potential for tunable performance.
{"title":"Influence of wire feed speed and torch speed on the mechanical properties of wire arc additively manufactured stainless steel","authors":"Laurent Terrenoir, J. Lartigau, A. Arjunan, Laura Laguna Salvadó, Christophe Merlo","doi":"10.1115/1.4063108","DOIUrl":"https://doi.org/10.1115/1.4063108","url":null,"abstract":"\u0000 Wire Arc Additive Manufacturing (WAAM) enables 3D printing of large high-value metal components. However, integrating WAAM into production lines requires a critical understanding of the influence of process parameters on the resulting material characteristics. As such, this research investigates the relationship between WAAM wire feed speed (WFS) and torch speed (TS) on the resulting mechanical characteristics of 316LSi thick parts (2.5 cm - 0.98 in). The experimental procedure is informed by a training matrix that allows parametric analysis of WFS and TS on the ultimate tensile strength (σult), yield strength (σy), elastic modulus (E), failure strain (εf), hardness (HV0.5) and dimensional accuracy (Da) of the printed samples. The research found that WAAM-processed 316LSi parts feature isotropic material properties despite variations in WFS and TS. The developed surrogate model offers five significant polynomial models capable of accurately predicting the influence of WAAM process parameters on σult, σy, εf, E and Da. The research found TS to be the most significant WAAM process parameter in comparison to WFS for σult and εy. On the contrary σy, E and Da were found to be primarily driven by WFS as opposed to TS. Overall, the paper for the first time presents an accurate surrogate model to predict the mechanical characteristics of WAAM 316LSi thick parts informed by wire feed speed and torch speed. The study demonstrates that the mechanical properties of WAAM-processed steel are primarily influenced by the underlying process parameters offering significant potential for tunable performance.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49612613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vision-based robots have been utilized for pick-and-place operations by their ability to find object poses. As they progress into handling a variety of objects with cluttered state, more flexible and lightweight operations have been presented. In this paper, an autonomous robotic bin-picking platform which combines human demonstration with a collaborative robot for the flexibility of the objects and YOLOv5 neural network model for the faster object localization without prior CAD models or dataset in the training. After simple human demonstration of which target object to pick and place, the raw color and depth images were refined, and the one on top of the bin was utilized to create synthetic images and annotations for the YOLOv5 model. To pick up the target object, the point cloud was lifted using the depth data corresponding to the result of the trained YOLOv5 model, and the object pose was estimated through matching them by Iterative Closest Points (ICP) algorithm. After picking up the target object, the robot placed it where the user defined in the previous human demonstration stage. From the result of experiments with four types of objects and four human demonstrations, it took a total of 0.5 seconds to recognize the target object and estimate the object pose. The success rate of object detection was 95.6%, and the pick-and-place motion of all the found objects were successful.
{"title":"Autonomous robotic bin picking platform generated from human demonstration and YOLOv5","authors":"Jinho Park, C. Han, M. Jun, Huitaek Yun","doi":"10.1115/1.4063107","DOIUrl":"https://doi.org/10.1115/1.4063107","url":null,"abstract":"\u0000 Vision-based robots have been utilized for pick-and-place operations by their ability to find object poses. As they progress into handling a variety of objects with cluttered state, more flexible and lightweight operations have been presented. In this paper, an autonomous robotic bin-picking platform which combines human demonstration with a collaborative robot for the flexibility of the objects and YOLOv5 neural network model for the faster object localization without prior CAD models or dataset in the training. After simple human demonstration of which target object to pick and place, the raw color and depth images were refined, and the one on top of the bin was utilized to create synthetic images and annotations for the YOLOv5 model. To pick up the target object, the point cloud was lifted using the depth data corresponding to the result of the trained YOLOv5 model, and the object pose was estimated through matching them by Iterative Closest Points (ICP) algorithm. After picking up the target object, the robot placed it where the user defined in the previous human demonstration stage. From the result of experiments with four types of objects and four human demonstrations, it took a total of 0.5 seconds to recognize the target object and estimate the object pose. The success rate of object detection was 95.6%, and the pick-and-place motion of all the found objects were successful.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43894778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years there has been increasing use of thin-walled structures with a plate thickness of 6mm-10mm in the construction of cruise ships. As one of the important processes of cruise ship construction, hybrid laser-arc welding, combing the advantages of laser welding and arc welding, is increasingly applied in thin-walled cruise ships with the objective of reducing panel deformation. However, due to the weak stiffness of the thin-walled structure with a continuous weld length of 4m-16m, complex welding deformation, e.g., buckling deformation will be prone to occur. This paper analyzed the deformation behavior of large-scale thin-walled cruise ship structures with the change of weld length, structural width, and plate thickness in hybrid laser-arc welding process. The buckling mode induced by the welding deformation is predicted based on the combination method of thermal elastic-plastic and inherent strain, as well as experimental verification. Comparing the deformation behavior of large thin-walled cruise ship structures, when the continuous weld length exceeds 7.5m during butt welding, the welding deformation mode transitions from bending deformation to buckling deformation. Comparing the buckling behavior of structures with different thicknesses at a length of 15m, a slight buckling occurs with a plate thickness of 10mm, but reducing the plate thickness to 6mm leads to severe buckling deformation with up to 7 half-wavelengths.
{"title":"Hybrid laser-arc welding-induced distortions analysis of large-scale thin-walled cruise ship structures","authors":"Liangfeng Li, Yansong Zhang","doi":"10.1115/1.4063109","DOIUrl":"https://doi.org/10.1115/1.4063109","url":null,"abstract":"\u0000 In recent years there has been increasing use of thin-walled structures with a plate thickness of 6mm-10mm in the construction of cruise ships. As one of the important processes of cruise ship construction, hybrid laser-arc welding, combing the advantages of laser welding and arc welding, is increasingly applied in thin-walled cruise ships with the objective of reducing panel deformation. However, due to the weak stiffness of the thin-walled structure with a continuous weld length of 4m-16m, complex welding deformation, e.g., buckling deformation will be prone to occur. This paper analyzed the deformation behavior of large-scale thin-walled cruise ship structures with the change of weld length, structural width, and plate thickness in hybrid laser-arc welding process. The buckling mode induced by the welding deformation is predicted based on the combination method of thermal elastic-plastic and inherent strain, as well as experimental verification. Comparing the deformation behavior of large thin-walled cruise ship structures, when the continuous weld length exceeds 7.5m during butt welding, the welding deformation mode transitions from bending deformation to buckling deformation. Comparing the buckling behavior of structures with different thicknesses at a length of 15m, a slight buckling occurs with a plate thickness of 10mm, but reducing the plate thickness to 6mm leads to severe buckling deformation with up to 7 half-wavelengths.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63503904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Richard Rothfelder, Florian Nahr, Dominic Bartels, Lova Chechik, Michael Schmidt
Abstract The progress of additive manufacturing (AM) within the last few decades has been phenomenal, progressing from a polymeric technique to a method for manufacturing metallic aerospace components. We take a look at various technological advances which have helped paved the way for this growth, focussing on European input, as currently, 54% of AM machines are sold by European manufacturers (Wohlers, Campbell, Diegel, Kowen, Mostow, and Fidan, 2022, “Wohlers Report 2022: 3D Printing and Additive Manufacturing Global State of the Industry,” Wohlers Associates, ASTM International, Fort Collins, Colo., Washington, DC). We take deep dives into several critical topics including sensing and monitoring, preheating, and multi-laser technology and illustrate how these develop from research ideas into industrial products. Finally, an outlook is provided, highlighting the topics currently gaining research traction, and which are expected to be the next key breakthroughs.
{"title":"A Brief History of the Progress of Laser Powder Bed Fusion of Metals in Europe","authors":"Richard Rothfelder, Florian Nahr, Dominic Bartels, Lova Chechik, Michael Schmidt","doi":"10.1115/1.4062788","DOIUrl":"https://doi.org/10.1115/1.4062788","url":null,"abstract":"Abstract The progress of additive manufacturing (AM) within the last few decades has been phenomenal, progressing from a polymeric technique to a method for manufacturing metallic aerospace components. We take a look at various technological advances which have helped paved the way for this growth, focussing on European input, as currently, 54% of AM machines are sold by European manufacturers (Wohlers, Campbell, Diegel, Kowen, Mostow, and Fidan, 2022, “Wohlers Report 2022: 3D Printing and Additive Manufacturing Global State of the Industry,” Wohlers Associates, ASTM International, Fort Collins, Colo., Washington, DC). We take deep dives into several critical topics including sensing and monitoring, preheating, and multi-laser technology and illustrate how these develop from research ideas into industrial products. Finally, an outlook is provided, highlighting the topics currently gaining research traction, and which are expected to be the next key breakthroughs.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136228735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"European Special Issue","authors":"Albert Shih, Vincent Wagner","doi":"10.1115/1.4063092","DOIUrl":"https://doi.org/10.1115/1.4063092","url":null,"abstract":"\u0000 Guest Editorial","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46360284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arjun Radhakrishnan, I. Georgilas, I. Hamerton, M. Shaffer, D. Ivanov
The formation of porosity is a major challenge in any composite manufacturing process particularly in the absence of vacuum assistance. Highly localised injection of polymer matrix into regions of interest in a dry preform is a route to manufacturing multi-matrix fibre-reinforced composites with high filler concentrations which are otherwise difficult to achieve. Such multi-matrix fibre-reinforced composite systems, which combine multiple resins in continuous form offer improved structural performance around stress concentrators and multi-functional capabilities, unlike traditional composite materials. As the process lacks vacuum assistance, porosity becomes a primary issue to be addressed. This paper presents a rheo-kinetic coupled rapid consolidation procedure for optimizing the quality of localised matrix patches. The procedure involves manufacturing trials and analytical consolidation models to determine the best processing program for minimal voidage in the patch. The results provide a step towards an efficient manufacturing process for designing multi-matrix composites without the need for complex vacuum bag arrangements. By optimizing the quality of the localised matrix patches, the procedure described in this paper can improve the overall performance of multi-matrix composite systems. The ability to create these composites without the need for complex vacuum bag arrangements can also reduce the manufacturing cost and time associated with the manufacturing of multi-matrix fibre-reinforced composites.
{"title":"MANUFACTURING MULTI-MATRIX COMPOSITES: OUT-OF-VACUUM BAG CONSOLIDATION","authors":"Arjun Radhakrishnan, I. Georgilas, I. Hamerton, M. Shaffer, D. Ivanov","doi":"10.1115/1.4063091","DOIUrl":"https://doi.org/10.1115/1.4063091","url":null,"abstract":"\u0000 The formation of porosity is a major challenge in any composite manufacturing process particularly in the absence of vacuum assistance. Highly localised injection of polymer matrix into regions of interest in a dry preform is a route to manufacturing multi-matrix fibre-reinforced composites with high filler concentrations which are otherwise difficult to achieve. Such multi-matrix fibre-reinforced composite systems, which combine multiple resins in continuous form offer improved structural performance around stress concentrators and multi-functional capabilities, unlike traditional composite materials. As the process lacks vacuum assistance, porosity becomes a primary issue to be addressed. This paper presents a rheo-kinetic coupled rapid consolidation procedure for optimizing the quality of localised matrix patches. The procedure involves manufacturing trials and analytical consolidation models to determine the best processing program for minimal voidage in the patch. The results provide a step towards an efficient manufacturing process for designing multi-matrix composites without the need for complex vacuum bag arrangements. By optimizing the quality of the localised matrix patches, the procedure described in this paper can improve the overall performance of multi-matrix composite systems. The ability to create these composites without the need for complex vacuum bag arrangements can also reduce the manufacturing cost and time associated with the manufacturing of multi-matrix fibre-reinforced composites.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45417113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amborish Banerjee, L. Da Silva, Hitesh Sharma, A. Platts, S. Rahimi
Inertia friction welding (IFW) is a solid-state welding process utilised for joining engineering materials. In this paper, a 2.5D finite element (FE) model was developed to simulate IFW of MLX®19 maraging steel. The predicted results showed a non-uniform temperature distribution, with a decrease in temperature from the periphery to the centre of weld interface. Higher temperature and lower stress distributions were predicted in the weld zone (WZ) and the adjacent regions in the vicinity of the WZ. The von-Mises effective stress, effective strain and strain-rate were investigated at different time steps of the FE simulation. The effective stress was minimum at the weld interface, and the effective strain and strain-rate attained a quasi-steady state status with the on-going IFW after a threshold time (~6.5 s). The simulated results were validated by comparing the predicted flash morphology with an actual IFW weld, and temperature profiles measured at specific locations using embedded thermo-couples. The difference between the experimental and the simulated results was ~4.7%, implying a good convergence of the model. Microstructural characterisations were performed across different regions and the observed features were found to be in agreement with the expected microstructure based on the simulated thermal profiles, which included almost complete (~90%) and partial transformation of martensite to austenite in the WZ and thermo-mechanically affected zone (TMAZ), respectively. Analyses of crystallographic texture, showed that the material (i.e., both transformed austenite and martensite) underwent pure shear deformation during IFW.
{"title":"Evolution of microstructure in MLX®19 maraging steel during rotary friction welding and finite element modelling of the process","authors":"Amborish Banerjee, L. Da Silva, Hitesh Sharma, A. Platts, S. Rahimi","doi":"10.1115/1.4063090","DOIUrl":"https://doi.org/10.1115/1.4063090","url":null,"abstract":"\u0000 Inertia friction welding (IFW) is a solid-state welding process utilised for joining engineering materials. In this paper, a 2.5D finite element (FE) model was developed to simulate IFW of MLX®19 maraging steel. The predicted results showed a non-uniform temperature distribution, with a decrease in temperature from the periphery to the centre of weld interface. Higher temperature and lower stress distributions were predicted in the weld zone (WZ) and the adjacent regions in the vicinity of the WZ. The von-Mises effective stress, effective strain and strain-rate were investigated at different time steps of the FE simulation. The effective stress was minimum at the weld interface, and the effective strain and strain-rate attained a quasi-steady state status with the on-going IFW after a threshold time (~6.5 s). The simulated results were validated by comparing the predicted flash morphology with an actual IFW weld, and temperature profiles measured at specific locations using embedded thermo-couples. The difference between the experimental and the simulated results was ~4.7%, implying a good convergence of the model. Microstructural characterisations were performed across different regions and the observed features were found to be in agreement with the expected microstructure based on the simulated thermal profiles, which included almost complete (~90%) and partial transformation of martensite to austenite in the WZ and thermo-mechanically affected zone (TMAZ), respectively. Analyses of crystallographic texture, showed that the material (i.e., both transformed austenite and martensite) underwent pure shear deformation during IFW.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46635748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although the production of polymer/carbon nanotube (CNT) nanocomposites has grown exponentially over the last years for a variety of applications, the availability of polymer/CNT filaments for the use in commercial 3D printing systems is very limited and, currently, little is known about the printability of recycled polymer/CNT nanocomposites. In this respect, the fused filament fabrication (FFF) of recycled thermoplastic polyurethane/carbon nanotube (TPU/CNT) nanocomposites was investigated with special focus on the piezoresistive behavior. Mechanically recycled and virgin TPU/CNT nanocomposites with different CNT contents (0.5, 1, 3, and 5 wt% by weight) were subjected to filament extrusion and FFF, and the changes induced by mechanical recycling, CNT contents and infill orientation were monitored by melt flow index, thermal, mechanical, electrical and piezoresistive properties. It was found that the recycled TPU nanocomposites exhibit very good printability with mechanical and electrical properties that are generally comparable with those for the virgin nanocomposites, the decrease of the elongation at break at 5 wt% CNTs being the primary challenge for the mechanical recycling of TPU/CNT nanocomposites. The 3D printed recycled TPU/CNT nanocomposites with 3 wt% and 5 wt% CNTs provide very good strain sensing behavior, with sensitivity and stretchability higher than those of the virgin nanocomposites. The findings of this work provide guidance for assessing the potential of using recycled TPU/CNT nanocomposites for 3D printing strain sensors with tuned sensitivity for a wide range of human motions.
{"title":"Investigation on the Printability of Recycled Thermoplastic Polyurethane/Carbon Nanotube Nanocomposites","authors":"F. Stan, I. Sandu, C. Fetecau","doi":"10.1115/1.4063036","DOIUrl":"https://doi.org/10.1115/1.4063036","url":null,"abstract":"\u0000 Although the production of polymer/carbon nanotube (CNT) nanocomposites has grown exponentially over the last years for a variety of applications, the availability of polymer/CNT filaments for the use in commercial 3D printing systems is very limited and, currently, little is known about the printability of recycled polymer/CNT nanocomposites. In this respect, the fused filament fabrication (FFF) of recycled thermoplastic polyurethane/carbon nanotube (TPU/CNT) nanocomposites was investigated with special focus on the piezoresistive behavior. Mechanically recycled and virgin TPU/CNT nanocomposites with different CNT contents (0.5, 1, 3, and 5 wt% by weight) were subjected to filament extrusion and FFF, and the changes induced by mechanical recycling, CNT contents and infill orientation were monitored by melt flow index, thermal, mechanical, electrical and piezoresistive properties. It was found that the recycled TPU nanocomposites exhibit very good printability with mechanical and electrical properties that are generally comparable with those for the virgin nanocomposites, the decrease of the elongation at break at 5 wt% CNTs being the primary challenge for the mechanical recycling of TPU/CNT nanocomposites. The 3D printed recycled TPU/CNT nanocomposites with 3 wt% and 5 wt% CNTs provide very good strain sensing behavior, with sensitivity and stretchability higher than those of the virgin nanocomposites. The findings of this work provide guidance for assessing the potential of using recycled TPU/CNT nanocomposites for 3D printing strain sensors with tuned sensitivity for a wide range of human motions.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48065122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tengteng Tang, Dylan Joralmon, Tochukwu Anyigbo, Xiangjia Li
The artificial cell is a biomimetic microcapsule system wherein biological materials are encapsulated by a thin membrane, which provides valuable information on the metabolism, morphology, development, and signal transduction pathways of the studied cell. However, it is extremely difficult to manufacture such systems. Mostly vesicles such as liposomes, polymersomes, and microcapsules are first produced by a high-pressure homogenizer and microfluidizer as an emulsion and then encapsulated microcapsules by the drop or emulsion method. Currently, acoustic levitation opens up entirely new possibilities for creating artificial cells because of its ability to suspend tiny droplets in an anti-gravity and non-contact manner. Herein, we propose a contactless printing of single-core or multi-core artificial cells based on acoustic levitation. First, the oscillation mode and microscopic morphology of the droplets under different ultrasonic vibration frequencies are shown by simulation, and the curing characteristics of the shell structure under different ultraviolet illumination conditions are quantitatively measured. The feasibility of manufacturing multi-core artificial cells and manufacturing sub-millimeter-scale particles based on oil trapping is extensively studied. To explore the morphological adaptability of artificial cells, ferromagnetic Fe3O4 nanoparticles are used to give cells magnetic responsive properties and the microscopic deformation and motion in microfluidic channels under the magnetic field are characterized. Finally, the proposed printing method proves the versatility of in-space contactless printing of complex 3D beam structures and provides a powerful platform for developing biomedical devices and microrobots and studying morphogenesis and synthetic biological systems
{"title":"Acoustic Levitation assisted Contactless Printing of Microdroplets for Biomedical Applications","authors":"Tengteng Tang, Dylan Joralmon, Tochukwu Anyigbo, Xiangjia Li","doi":"10.1115/1.4062971","DOIUrl":"https://doi.org/10.1115/1.4062971","url":null,"abstract":"\u0000 The artificial cell is a biomimetic microcapsule system wherein biological materials are encapsulated by a thin membrane, which provides valuable information on the metabolism, morphology, development, and signal transduction pathways of the studied cell. However, it is extremely difficult to manufacture such systems. Mostly vesicles such as liposomes, polymersomes, and microcapsules are first produced by a high-pressure homogenizer and microfluidizer as an emulsion and then encapsulated microcapsules by the drop or emulsion method. Currently, acoustic levitation opens up entirely new possibilities for creating artificial cells because of its ability to suspend tiny droplets in an anti-gravity and non-contact manner. Herein, we propose a contactless printing of single-core or multi-core artificial cells based on acoustic levitation. First, the oscillation mode and microscopic morphology of the droplets under different ultrasonic vibration frequencies are shown by simulation, and the curing characteristics of the shell structure under different ultraviolet illumination conditions are quantitatively measured. The feasibility of manufacturing multi-core artificial cells and manufacturing sub-millimeter-scale particles based on oil trapping is extensively studied. To explore the morphological adaptability of artificial cells, ferromagnetic Fe3O4 nanoparticles are used to give cells magnetic responsive properties and the microscopic deformation and motion in microfluidic channels under the magnetic field are characterized. Finally, the proposed printing method proves the versatility of in-space contactless printing of complex 3D beam structures and provides a powerful platform for developing biomedical devices and microrobots and studying morphogenesis and synthetic biological systems","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41538908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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