Pub Date : 2022-04-27DOI: 10.1088/2399-7532/ac4c95
S. Smoukov
It is hard to imagine with the progress in robotics that current approaches are lacking somewhere, yet they will not be applicable to the majority of robots in the near future. We are on the verge of two new transitions that will transform robotics. One is already under way -- the miniaturization of robots, to the point where invisible, microscopic robots could be around us and inside us, performing monitoring or even life-saving functions. We have seen systematic bio-inspired efforts to create microbe-like, microscopic robots. The trend has parallels with miniaturization in the electronics industry, where exponentially smaller and more energy efficient units have been produced each generation. To put this statement in context, examples already include magnetic microswimmer robots, employing bacterial modes of locomotion, which are biocompatible, potentially ready for integration within our bodies. They require lithography to create clever microscopic screw-type structures, enough to produce the cork-screw swimming movement. Such micro-robots have encapsulated, picked, and delivered cells, protecting them from shear forces in fluids, while others have captured non-motile sperm, propelled them, and ultimately fertilized an egg. We explore how such developments in micro-robots will change our world in the relatively near future. The second trend is bottom-up robotics, growing robots from a solution medium, as if they were bacteria. This field is emerging at the intersection of a number of disciplines, discussed below. An overarching common theme is the creation of artificial life from a non-biological starting point.
{"title":"Sustainably Grown: The Underdog Robots of the Future","authors":"S. Smoukov","doi":"10.1088/2399-7532/ac4c95","DOIUrl":"https://doi.org/10.1088/2399-7532/ac4c95","url":null,"abstract":"It is hard to imagine with the progress in robotics that current approaches are lacking somewhere, yet they will not be applicable to the majority of robots in the near future. We are on the verge of two new transitions that will transform robotics. One is already under way -- the miniaturization of robots, to the point where invisible, microscopic robots could be around us and inside us, performing monitoring or even life-saving functions. We have seen systematic bio-inspired efforts to create microbe-like, microscopic robots. The trend has parallels with miniaturization in the electronics industry, where exponentially smaller and more energy efficient units have been produced each generation. To put this statement in context, examples already include magnetic microswimmer robots, employing bacterial modes of locomotion, which are biocompatible, potentially ready for integration within our bodies. They require lithography to create clever microscopic screw-type structures, enough to produce the cork-screw swimming movement. Such micro-robots have encapsulated, picked, and delivered cells, protecting them from shear forces in fluids, while others have captured non-motile sperm, propelled them, and ultimately fertilized an egg. We explore how such developments in micro-robots will change our world in the relatively near future. The second trend is bottom-up robotics, growing robots from a solution medium, as if they were bacteria. This field is emerging at the intersection of a number of disciplines, discussed below. An overarching common theme is the creation of artificial life from a non-biological starting point.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":"abs/2206.10306 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61174622","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}
Pub Date : 2022-04-21DOI: 10.1088/2399-7532/ac6556
K. Dorsey, Huiying Huang, Yu-Ting Wen
Origami patterns have previously been investigated for novel mechanical properties and applications to soft and deployable robotics. This work models and characterizes the mechanical and electrical properties of origami-patterned capacitive strain sensors. Miura-patterned capacitors with different fold angles are fabricated with a silicone body and foil electrodes. The planar strain sensitivity ratio is tunable from 0.2 to 0.5 with fold angles, while all-soft patterns demonstrate low mechanical tunability through fold angle. We conclude by offering recommendations for designing and modeling future origami-patterned soft material sensors.
{"title":"Origami-patterned capacitor with programmed strain sensitivity","authors":"K. Dorsey, Huiying Huang, Yu-Ting Wen","doi":"10.1088/2399-7532/ac6556","DOIUrl":"https://doi.org/10.1088/2399-7532/ac6556","url":null,"abstract":"Origami patterns have previously been investigated for novel mechanical properties and applications to soft and deployable robotics. This work models and characterizes the mechanical and electrical properties of origami-patterned capacitive strain sensors. Miura-patterned capacitors with different fold angles are fabricated with a silicone body and foil electrodes. The planar strain sensitivity ratio is tunable from 0.2 to 0.5 with fold angles, while all-soft patterns demonstrate low mechanical tunability through fold angle. We conclude by offering recommendations for designing and modeling future origami-patterned soft material sensors.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42830951","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}
Pub Date : 2022-04-08DOI: 10.1088/2399-7532/ac65c8
Maria Francesca Pernice, Guocheng Qi, E. Senokos, D. B. Anthony, S. Nguyen, M. Valkova, E. Greenhalgh, M. Shaffer, A. Kucernak
This work investigated and developed a protocol for establishing the multifunctional performance of a structural supercapacitor: a composite which can simultaneously carry mechanical load whilst storing electrical energy. The Structural Supercapacitor consisted of carbon aerogel (CAG) reinforced carbon fibre electrodes which sandwiched a woven glass fibre lamina and was infused with a structural electrolyte (SE). This was compared to two monofunctional devices: a Monofunctional Supercapacitor and a Monofunctional Laminate in which the SE had been replaced by ionic liquid and a structural epoxy, respectively. In the Monofunctional Supercapacitor, the considerable surface area of the CAG and ionic capacity of the liquid electrolyte resulted in a high device normalised capacitance (1731 mF g−1). However, in the Structural Supercapacitor the SE presented meso-scale heterogeneity, obstructing the CAG pores with thin films of epoxy. This resulted in a considerable reduction in electrochemical performance, with a drop in the device normalised capacitance to 212 mF g−1. Regarding mechanical performance, it was shown that the CAG had promoted brittle fracture, leading to a severe depression in the tensile and in-plane shear strengths. The Structural Supercapacitor presented a tensile modulus and strength of 33 GPa and 110 MPa, respectively: a 15% and 11% drop in tensile modulus and strength, respectively, compared to that of the Monofunctional Laminate. However, under in-plane shear the soft SE dominated, leading to about a 44% drop in shear modulus (1.7 GPa) and strength (13.7 MPa at 1% shear strain). This work has provided an insight into the hurdles associated with demonstrating multifunctionality, including the scaling challenges for electrochemical and mechanical characterisation and the need to report both active material and device normalised data. The emergence and development of such structural power composites could address the issue of parasitic battery mass in transportation, and hence realise full electrification of aircraft and cars.
{"title":"Mechanical, electrochemical and multifunctional performance of a CFRP/carbon aerogel structural supercapacitor and its corresponding monofunctional equivalents","authors":"Maria Francesca Pernice, Guocheng Qi, E. Senokos, D. B. Anthony, S. Nguyen, M. Valkova, E. Greenhalgh, M. Shaffer, A. Kucernak","doi":"10.1088/2399-7532/ac65c8","DOIUrl":"https://doi.org/10.1088/2399-7532/ac65c8","url":null,"abstract":"This work investigated and developed a protocol for establishing the multifunctional performance of a structural supercapacitor: a composite which can simultaneously carry mechanical load whilst storing electrical energy. The Structural Supercapacitor consisted of carbon aerogel (CAG) reinforced carbon fibre electrodes which sandwiched a woven glass fibre lamina and was infused with a structural electrolyte (SE). This was compared to two monofunctional devices: a Monofunctional Supercapacitor and a Monofunctional Laminate in which the SE had been replaced by ionic liquid and a structural epoxy, respectively. In the Monofunctional Supercapacitor, the considerable surface area of the CAG and ionic capacity of the liquid electrolyte resulted in a high device normalised capacitance (1731 mF g−1). However, in the Structural Supercapacitor the SE presented meso-scale heterogeneity, obstructing the CAG pores with thin films of epoxy. This resulted in a considerable reduction in electrochemical performance, with a drop in the device normalised capacitance to 212 mF g−1. Regarding mechanical performance, it was shown that the CAG had promoted brittle fracture, leading to a severe depression in the tensile and in-plane shear strengths. The Structural Supercapacitor presented a tensile modulus and strength of 33 GPa and 110 MPa, respectively: a 15% and 11% drop in tensile modulus and strength, respectively, compared to that of the Monofunctional Laminate. However, under in-plane shear the soft SE dominated, leading to about a 44% drop in shear modulus (1.7 GPa) and strength (13.7 MPa at 1% shear strain). This work has provided an insight into the hurdles associated with demonstrating multifunctionality, including the scaling challenges for electrochemical and mechanical characterisation and the need to report both active material and device normalised data. The emergence and development of such structural power composites could address the issue of parasitic battery mass in transportation, and hence realise full electrification of aircraft and cars.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48096973","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}
Pub Date : 2022-02-16DOI: 10.1088/2399-7532/ac55fd
Hongshuang Guo, H. Zeng, A. Priimagi
Stimuli-responsive polymers provide unmatched oppurtunities for remotely controlled soft robots navigating in complex environments. Many of the responsive-material-based soft robots can walk on open surfaces, with movement directionality dictated by the friction anistropy at the robot-substrate interface. Translocation in one-dimensional space such as on a tubular surface is much more challenging due to the lack of efficient friction control strategies. Such strategies could in long term provide novel application prospects in, e.g., overhaul at high altitudes and robotic operation within confined enivronments. In this work, we realize a liquid-crystal-elastomer-based soft robot that can move on a tubular surface through optical control over the grasping force exerted on the surface. Photoactuation allows for efficient, remotely switched gripping and friction control which, together with cyclic body deformation, enables light-fueled climbing on tubular surfaces of glass, wood, metal, and plastic with various cross-sections. We demonstrate vertical climbing, moving obstacles along the path, and load-carrying ability (at least 3×body weight). We believe our design to offer new prospects for wirelessly driven soft micro-robotics in confined spaces.
{"title":"Optically controlled grasping-slipping robot moving on tubular surfaces","authors":"Hongshuang Guo, H. Zeng, A. Priimagi","doi":"10.1088/2399-7532/ac55fd","DOIUrl":"https://doi.org/10.1088/2399-7532/ac55fd","url":null,"abstract":"\u0000 Stimuli-responsive polymers provide unmatched oppurtunities for remotely controlled soft robots navigating in complex environments. Many of the responsive-material-based soft robots can walk on open surfaces, with movement directionality dictated by the friction anistropy at the robot-substrate interface. Translocation in one-dimensional space such as on a tubular surface is much more challenging due to the lack of efficient friction control strategies. Such strategies could in long term provide novel application prospects in, e.g., overhaul at high altitudes and robotic operation within confined enivronments. In this work, we realize a liquid-crystal-elastomer-based soft robot that can move on a tubular surface through optical control over the grasping force exerted on the surface. Photoactuation allows for efficient, remotely switched gripping and friction control which, together with cyclic body deformation, enables light-fueled climbing on tubular surfaces of glass, wood, metal, and plastic with various cross-sections. We demonstrate vertical climbing, moving obstacles along the path, and load-carrying ability (at least 3×body weight). We believe our design to offer new prospects for wirelessly driven soft micro-robotics in confined spaces.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47800161","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}
Pub Date : 2022-01-27DOI: 10.1088/2399-7532/ac4fb8
Yijun Chen, J. Boyd, M. Naraghi
The goal of this research is to establish a highly compact on-demand release platform for functional materials where porous nanofibers serve as the host, heat-based release trigger and temperature controller for regulated release. The ability to store functional materials in fibers and release them on demand via external signals may open up new frontiers in areas such as smart textiles and autonomous composites. The host material was porous carbon nanofibers (CNFs), which encapsulated functional materials, protected by a thin polymeric coating to thermally regulate the release. This platform was used to store Gentian violet (GV), an antibacterial material, and release it with highly controllable rates in aqueous environment. The high porosity of the CNF yarns, both inter- and intra-fiber porosity, resulted in a mass loading of as high as ∼50 wt%. The active release was triggered via passing electrical signals through CNF yarn backbone, thereby heating the coating. The rate of release as a function of temperature was measured. It was concluded that the release mechanism is via thermally augmented and reversible diffusion rates of GV and water through the coating. By applying electric current, the diffusion coefficient of the coating was increased, and the release rate dramatically increased in a reversible fashion by as much as 39×.
{"title":"Encapsulation and on-demand release of functional materials from conductive nanofibers via electrical signals","authors":"Yijun Chen, J. Boyd, M. Naraghi","doi":"10.1088/2399-7532/ac4fb8","DOIUrl":"https://doi.org/10.1088/2399-7532/ac4fb8","url":null,"abstract":"The goal of this research is to establish a highly compact on-demand release platform for functional materials where porous nanofibers serve as the host, heat-based release trigger and temperature controller for regulated release. The ability to store functional materials in fibers and release them on demand via external signals may open up new frontiers in areas such as smart textiles and autonomous composites. The host material was porous carbon nanofibers (CNFs), which encapsulated functional materials, protected by a thin polymeric coating to thermally regulate the release. This platform was used to store Gentian violet (GV), an antibacterial material, and release it with highly controllable rates in aqueous environment. The high porosity of the CNF yarns, both inter- and intra-fiber porosity, resulted in a mass loading of as high as ∼50 wt%. The active release was triggered via passing electrical signals through CNF yarn backbone, thereby heating the coating. The rate of release as a function of temperature was measured. It was concluded that the release mechanism is via thermally augmented and reversible diffusion rates of GV and water through the coating. By applying electric current, the diffusion coefficient of the coating was increased, and the release rate dramatically increased in a reversible fashion by as much as 39×.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45546568","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}
Pub Date : 2022-01-12DOI: 10.1088/2399-7532/ac4a86
Nuttanit Pramounmat, Katherine Yan, Jadon Wolf, J. Renner
Platinum-binding (Pt-binding) peptides have been used for fabrication of complex platinum nanomaterials such as catalysts, metallopharmaceuticals, and electrodes. In this review, we present an understanding of the mechanisms behind Pt-binding peptides and their applications as multifunctional biomaterials. We discuss how the surface recognition, roles of individual amino acids, and arrangement of amino acid sequences interplay. Our summary on the current state of understanding of Pt-binding peptides highlights opportunities for interdisciplinary research which will expand the applicability of these multifunctional peptides.
{"title":"Platinum-binding peptides: understanding of selective binding and multifunctionality","authors":"Nuttanit Pramounmat, Katherine Yan, Jadon Wolf, J. Renner","doi":"10.1088/2399-7532/ac4a86","DOIUrl":"https://doi.org/10.1088/2399-7532/ac4a86","url":null,"abstract":"Platinum-binding (Pt-binding) peptides have been used for fabrication of complex platinum nanomaterials such as catalysts, metallopharmaceuticals, and electrodes. In this review, we present an understanding of the mechanisms behind Pt-binding peptides and their applications as multifunctional biomaterials. We discuss how the surface recognition, roles of individual amino acids, and arrangement of amino acid sequences interplay. Our summary on the current state of understanding of Pt-binding peptides highlights opportunities for interdisciplinary research which will expand the applicability of these multifunctional peptides.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42523421","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}
Pub Date : 2022-01-05DOI: 10.1088/2399-7532/ac4837
Jacob Eaton, M. Naraghi, J. Boyd
The emerging research field of structural batteries aims to combine the functions of load bearing and energy storage to improve system-level energy storage in battery-powered vehicles and consumer products. Structural batteries, when implemented in electric vehicles, will be exposed to greater temperature fluctuations than conventional batteries in EVs. However, there is a lack of published data regarding how these thermal boundary conditions impact power capabilities of the structural batteries. To fill this gap, the present work simulates transient temperature-dependent specific power capabilities of high aspect ratio structural battery composite by solving one-dimensional heat transfer equation with heat source and convective boundary conditions. Equivalent circuit modeling of resistivity-induced losses is used with a second-order finite difference method to examine battery performance. More than 60 different run configurations are evaluated, examining how thermal boundary conditions and internal heat influence power capabilities and multifunctional efficiency of the structural battery. The simulated structural battery composite is shown to have good specific Young’s modulus (79.5 to 80.3% of aluminum), a specific energy of 158 Wh/kg, and specific power of 41.2 to 55.2 W/kg, providing a multifunctional efficiency of 1.15 to 1.17 depending on configuration and thermal loading conditions and demonstrating the potential of load-bearing structural batteries to achieve mass savings. This work emphasizes the dependency of power efficiency on cell design and external environmental conditions. Insulating material is shown to improve multifunctional efficiency, particularly for low ambient temperatures. It is demonstrated that as cell temperature increases due to high ambient temperature or heat generation in the battery, the specific power efficiency increases exponentially due to a favorable nonlinear relation between ionic conductivity and cell temperature. The simulations also demonstrate a thermal feedback loop where resistivity-induced power losses can lead to self-regulation of cell temperature. This effect reduces run-averaged losses, particularly at low ambient temperature.
{"title":"Evaluating multifunctional efficiency of a structural battery composite via thermo-electro-chemical modelling","authors":"Jacob Eaton, M. Naraghi, J. Boyd","doi":"10.1088/2399-7532/ac4837","DOIUrl":"https://doi.org/10.1088/2399-7532/ac4837","url":null,"abstract":"\u0000 The emerging research field of structural batteries aims to combine the functions of load bearing and energy storage to improve system-level energy storage in battery-powered vehicles and consumer products. Structural batteries, when implemented in electric vehicles, will be exposed to greater temperature fluctuations than conventional batteries in EVs. However, there is a lack of published data regarding how these thermal boundary conditions impact power capabilities of the structural batteries. To fill this gap, the present work simulates transient temperature-dependent specific power capabilities of high aspect ratio structural battery composite by solving one-dimensional heat transfer equation with heat source and convective boundary conditions. Equivalent circuit modeling of resistivity-induced losses is used with a second-order finite difference method to examine battery performance. More than 60 different run configurations are evaluated, examining how thermal boundary conditions and internal heat influence power capabilities and multifunctional efficiency of the structural battery. The simulated structural battery composite is shown to have good specific Young’s modulus (79.5 to 80.3% of aluminum), a specific energy of 158 Wh/kg, and specific power of 41.2 to 55.2 W/kg, providing a multifunctional efficiency of 1.15 to 1.17 depending on configuration and thermal loading conditions and demonstrating the potential of load-bearing structural batteries to achieve mass savings. This work emphasizes the dependency of power efficiency on cell design and external environmental conditions. Insulating material is shown to improve multifunctional efficiency, particularly for low ambient temperatures. It is demonstrated that as cell temperature increases due to high ambient temperature or heat generation in the battery, the specific power efficiency increases exponentially due to a favorable nonlinear relation between ionic conductivity and cell temperature. The simulations also demonstrate a thermal feedback loop where resistivity-induced power losses can lead to self-regulation of cell temperature. This effect reduces run-averaged losses, particularly at low ambient temperature.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43143831","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}
Pub Date : 2022-01-05DOI: 10.1088/2399-7532/ac4836
Neng Xia, Dongdong Jin, V. Iacovacci, Li Zhang
Miniature robots and actuators with micrometer or millimeter scale size can be driven by diverse power sources, e.g., chemical fuels, light, magnetic, and acoustic fields. These machines have the potential to access complex narrow spaces, execute medical tasks, perform environmental monitoring, and manipulate micro-objects. Recent advancements in 3D printing techniques have demonstrated great benefits in manufacturing small-scale structures such as customized design with programmable physical properties. Combining 3D printing methods, functional polymers, and active control strategies enables these miniature machines with diverse functionalities to broaden their potentials in medical applications. Herein, this review provides an overview of 3D printing techniques applicable for the fabrication of small-scale machines and printable functional materials, including shape-morphing materials, biomaterials, composite polymers, and self-healing polymers. Functions and applications of tiny robots and actuators fabricated by 3D printing and future perspectives toward small-scale intelligent machines are discussed.
{"title":"3D printing of functional polymers for miniature machines","authors":"Neng Xia, Dongdong Jin, V. Iacovacci, Li Zhang","doi":"10.1088/2399-7532/ac4836","DOIUrl":"https://doi.org/10.1088/2399-7532/ac4836","url":null,"abstract":"\u0000 Miniature robots and actuators with micrometer or millimeter scale size can be driven by diverse power sources, e.g., chemical fuels, light, magnetic, and acoustic fields. These machines have the potential to access complex narrow spaces, execute medical tasks, perform environmental monitoring, and manipulate micro-objects. Recent advancements in 3D printing techniques have demonstrated great benefits in manufacturing small-scale structures such as customized design with programmable physical properties. Combining 3D printing methods, functional polymers, and active control strategies enables these miniature machines with diverse functionalities to broaden their potentials in medical applications. Herein, this review provides an overview of 3D printing techniques applicable for the fabrication of small-scale machines and printable functional materials, including shape-morphing materials, biomaterials, composite polymers, and self-healing polymers. Functions and applications of tiny robots and actuators fabricated by 3D printing and future perspectives toward small-scale intelligent machines are discussed.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44376883","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}
Graphene quantum dots (GQDs) exhibit abundant magnetic edge states with promising applications in spintronics. Hexagonal zigzag GQDs possess a ground state with an antiferromagnetic (AFM) inter-edge coupling, followed by a metastable state with ferromagnetic (FM) inter-edge coupling. By analyzing the Hubbard model and performing large-scale spin-polarized density functional theory calculations containing thousands of atoms, we predict a series of new mixed magnetic edge states of GQDs arising from the size effect, namely mix-n, where n is the number of spin arrangement parts at each edge, with parallel spin in the same part and anti-parallel spin between adjacent parts. In particular, we demonstrate that the mix-2 state of bare GQDs (C6N2) appears when N ≥ 4 and the mix-3 state appears when N ≥ 6, where N is the number of six-membered-ring at each edge, while the mix-2 and mix-3 magnetic states appear in the hydrogenated GQDs with N = 13 and N = 15, respectively.
{"title":"Mixed magnetic edge states in graphene quantum dots","authors":"Jun-ye Li, Xiaofeng Liu, Lingyun Wan, Xinming Qin, Wei Hu, Jinlong Yang","doi":"10.1088/2399-7532/ac44fe","DOIUrl":"https://doi.org/10.1088/2399-7532/ac44fe","url":null,"abstract":"\u0000 Graphene quantum dots (GQDs) exhibit abundant magnetic edge states with promising applications in spintronics. Hexagonal zigzag GQDs possess a ground state with an antiferromagnetic (AFM) inter-edge coupling, followed by a metastable state with ferromagnetic (FM) inter-edge coupling. By analyzing the Hubbard model and performing large-scale spin-polarized density functional theory calculations containing thousands of atoms, we predict a series of new mixed magnetic edge states of GQDs arising from the size effect, namely mix-n, where n is the number of spin arrangement parts at each edge, with parallel spin in the same part and anti-parallel spin between adjacent parts. In particular, we demonstrate that the mix-2 state of bare GQDs (C6N2) appears when N ≥ 4 and the mix-3 state appears when N ≥ 6, where N is the number of six-membered-ring at each edge, while the mix-2 and mix-3 magnetic states appear in the hydrogenated GQDs with N = 13 and N = 15, respectively.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48548498","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}
Pub Date : 2021-10-14DOI: 10.1088/2399-7532/ac2faf
Onur Bas, B. Gorissen, Simon Luposchainsky, T. Shabab, K. Bertoldi, D. Hutmacher
The quest for an advanced soft robotic actuator technology that is fast and can execute a wide range of application-specific tasks at multiple length scales is still ongoing. Here, we demonstrate a new design and manufacturing strategy that leads to high-speed inflatable actuators exhibiting diverse movements. Our approach leverages the concept of miniaturisation to reduce the required volume of fluid for actuation as well as fibre-reinforcement to improve the efficiency of actuators in converting delivered fluids into fast and predictable movement. To fabricate the designs, we employ a class of additive manufacturing technology called melt electrowriting. We demonstrate 3D printing of microfibre architectures on soft elastomers with precision at unprecedently small length scales, leading to miniaturised composite actuators with highly controlled deformation characteristics. We show that owing to their small dimensions and deterministically designed fibrous networks, our actuators require extremely low amounts of fluid to inflate. We demonstrate that actuators with a length of 10–15 mm and an inner diameter 1 mm can reach their full range of motion within∼20 ms without exploiting snapping instabilities or material non-linearities. We display the speed of our actuators by building an ultrafast, soft flycatcher. We also show that our actuators outperform their counterparts with respect to achievable movement diversity and complexity.
{"title":"Ultrafast, miniature soft actuators","authors":"Onur Bas, B. Gorissen, Simon Luposchainsky, T. Shabab, K. Bertoldi, D. Hutmacher","doi":"10.1088/2399-7532/ac2faf","DOIUrl":"https://doi.org/10.1088/2399-7532/ac2faf","url":null,"abstract":"The quest for an advanced soft robotic actuator technology that is fast and can execute a wide range of application-specific tasks at multiple length scales is still ongoing. Here, we demonstrate a new design and manufacturing strategy that leads to high-speed inflatable actuators exhibiting diverse movements. Our approach leverages the concept of miniaturisation to reduce the required volume of fluid for actuation as well as fibre-reinforcement to improve the efficiency of actuators in converting delivered fluids into fast and predictable movement. To fabricate the designs, we employ a class of additive manufacturing technology called melt electrowriting. We demonstrate 3D printing of microfibre architectures on soft elastomers with precision at unprecedently small length scales, leading to miniaturised composite actuators with highly controlled deformation characteristics. We show that owing to their small dimensions and deterministically designed fibrous networks, our actuators require extremely low amounts of fluid to inflate. We demonstrate that actuators with a length of 10–15 mm and an inner diameter 1 mm can reach their full range of motion within∼20 ms without exploiting snapping instabilities or material non-linearities. We display the speed of our actuators by building an ultrafast, soft flycatcher. We also show that our actuators outperform their counterparts with respect to achievable movement diversity and complexity.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48336276","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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