Due to considerable progress in DNA nanotechnology, DNA is gaining significant attention as a programmable building block for the next generation of soft biomaterials. DNA has been used as either the only component to form all-DNA hydrogels or a cross-linker or functional entity to form hybrid DNA hydrogels through physical interactions or chemical reactions. The formed hydrogels exhibit adequate biocompatibility, convenient programmability, tunable multifunctionality, and capability of precise molecular recognition, making them an irreplaceable polymeric platform for interfacing biology. Responsive DNA hydrogels that are prepared through hybridization of DNA sticky ends, formation of i-motifs, enzymatic ligation, and enzymatic polymerization are commonly reported nowadays, which can undergo disassembly induced by various triggers, including alteration in ionic strength, pH, temperature, and biomolecules. These hydrogels are envisioned for applications of drug delivery and biosensing. This perspective aims to assess the most recent and important developments in this emerging class of biomedically useful DNA hydrogels.
{"title":"Biomedical DNA hydrogels","authors":"Yong Hu","doi":"10.20517/ss.2021.20","DOIUrl":"https://doi.org/10.20517/ss.2021.20","url":null,"abstract":"Due to considerable progress in DNA nanotechnology, DNA is gaining significant attention as a programmable building block for the next generation of soft biomaterials. DNA has been used as either the only component to form all-DNA hydrogels or a cross-linker or functional entity to form hybrid DNA hydrogels through physical interactions or chemical reactions. The formed hydrogels exhibit adequate biocompatibility, convenient programmability, tunable multifunctionality, and capability of precise molecular recognition, making them an irreplaceable polymeric platform for interfacing biology. Responsive DNA hydrogels that are prepared through hybridization of DNA sticky ends, formation of i-motifs, enzymatic ligation, and enzymatic polymerization are commonly reported nowadays, which can undergo disassembly induced by various triggers, including alteration in ionic strength, pH, temperature, and biomolecules. These hydrogels are envisioned for applications of drug delivery and biosensing. This perspective aims to assess the most recent and important developments in this emerging class of biomedically useful DNA hydrogels.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67659991","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}
Human-machine interactions are becoming increasingly required for intelligent sensing and effective manipulation. Recent developments in flexible piezoelectric sensors with short response time and high force-electric interconversion efficiency present a tendency toward facilitating diverse human-machine interactive applications. Here, we review the development of flexible piezoelectric human-machine interactions in the context of robotic control, the Internet of Things, sports coaching and acoustic therapeutics. The synthesis of unique materials, the distinct design of device structures, the typical applications of piezoelectric human-machine interactions and the integration of cutting-edge technologies are elaborated in detail based on recent research. Finally, we highlight the current challenges and directions for the development of piezoelectric human-machine interactions for more advanced application scenarios.
{"title":"Recent progress in flexible piezoelectric devices toward human-machine interactions","authors":"","doi":"10.20517/ss.2022.23","DOIUrl":"https://doi.org/10.20517/ss.2022.23","url":null,"abstract":"Human-machine interactions are becoming increasingly required for intelligent sensing and effective manipulation. Recent developments in flexible piezoelectric sensors with short response time and high force-electric interconversion efficiency present a tendency toward facilitating diverse human-machine interactive applications. Here, we review the development of flexible piezoelectric human-machine interactions in the context of robotic control, the Internet of Things, sports coaching and acoustic therapeutics. The synthesis of unique materials, the distinct design of device structures, the typical applications of piezoelectric human-machine interactions and the integration of cutting-edge technologies are elaborated in detail based on recent research. Finally, we highlight the current challenges and directions for the development of piezoelectric human-machine interactions for more advanced application scenarios.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67660176","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}
Intrinsically soft and stretchable bioelectronics exhibit tissue-like mechanical behavior that enables the seamless integration of electronic devices with the human body to achieve high-quality biosignal recording and high-efficacy neural modulation. The conducting polymer poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) shows significant promise in this field because of its high conductivity, excellent biocompatibility and commercial availability. However, pristine PEDOT:PSS is brittle and rigid and thus cannot be used in soft and stretchable electronics. More effort is therefore required to engineer PEDOT:PSS into a stretchable conductor that meets the demands of bioelectronics. In this perspective, we review the recent progress and propose the possible future directions of PEDOT:PSS-based bioelectronics.
{"title":"PEDOT:PSS-based intrinsically soft and stretchable bioelectronics","authors":"Gang Li","doi":"10.20517/ss.2022.07","DOIUrl":"https://doi.org/10.20517/ss.2022.07","url":null,"abstract":"Intrinsically soft and stretchable bioelectronics exhibit tissue-like mechanical behavior that enables the seamless integration of electronic devices with the human body to achieve high-quality biosignal recording and high-efficacy neural modulation. The conducting polymer poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) shows significant promise in this field because of its high conductivity, excellent biocompatibility and commercial availability. However, pristine PEDOT:PSS is brittle and rigid and thus cannot be used in soft and stretchable electronics. More effort is therefore required to engineer PEDOT:PSS into a stretchable conductor that meets the demands of bioelectronics. In this perspective, we review the recent progress and propose the possible future directions of PEDOT:PSS-based bioelectronics.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67659680","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}
Xiangchao Fan, Zhao-jun Chen, Haotian Sun, S. Zeng, Ruonan Liu, Ye Tian
With the continuous development of soft conductive materials, polyelectrolyte-based conductive hydrogels have gradually become a major research hotspot because of their strong application potential. This review first considers the basic conductive theory of hydrogels, which can be divided into the hydrogel structure and zwitterionic enhancing conductivity theories. We then classify polyelectrolyte-based conductive hydrogels into different types, including double, ionic-hydrogen bond, hydrogen bond,and physically crosslinked networks. Furthermore, the mechanical, electrical, and self-healing properties and fatigue and temperature interference resistance of polyelectrolyte-based conductive hydrogels are described in detail. We then discuss their versatile applications in strain sensors, solid-state supercapacitors, visual displays, wound dressings, and drug delivery. Finally, we offer perspectives on future research trends for polyelectrolyte-based conductive hydrogels.
{"title":"Polyelectrolyte-based conductive hydrogels: from theory to applications","authors":"Xiangchao Fan, Zhao-jun Chen, Haotian Sun, S. Zeng, Ruonan Liu, Ye Tian","doi":"10.20517/ss.2022.09","DOIUrl":"https://doi.org/10.20517/ss.2022.09","url":null,"abstract":"With the continuous development of soft conductive materials, polyelectrolyte-based conductive hydrogels have gradually become a major research hotspot because of their strong application potential. This review first considers the basic conductive theory of hydrogels, which can be divided into the hydrogel structure and zwitterionic enhancing conductivity theories. We then classify polyelectrolyte-based conductive hydrogels into different types, including double, ionic-hydrogen bond, hydrogen bond,and physically crosslinked networks. Furthermore, the mechanical, electrical, and self-healing properties and fatigue and temperature interference resistance of polyelectrolyte-based conductive hydrogels are described in detail. We then discuss their versatile applications in strain sensors, solid-state supercapacitors, visual displays, wound dressings, and drug delivery. Finally, we offer perspectives on future research trends for polyelectrolyte-based conductive hydrogels.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67659750","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}
Xindi Sun, Fengyuan Zhang, Lingyu Zhang, Guimin Liu, Yalong Wang, Yao Wang, Yuan Deng
Mechanical energy conversion based on piezoelectric principle has received much attention due to its promising applications in sustainable power supply systems and sensor technology. Ferroelectric poly(vinylidene fluoride) (PVDF) combines the advantages of both good electromechanical coupling and easy processability, yet the low piezoelectric coefficient limits its output performances thus cannot meet the increasing requirements for power generation and sensing. Here, inorganic metal halide perovskite CsPbBr3 (CPB) nanoparticles have been incorporated into the PVDF fibers via electrospinning technique, where an in situ crystallization and growth process of CPB nanoparticles have been established. Meanwhile, both the CPB nanoparticles and PVDF fibers are poled by the electric field during electrospinning process, which promotes the formation of polar phase of PVDF and the distortion of CPB lattice, resulting in greatly enhanced piezoelectric performances of CPB/PVDF composites. The output performances under external force of the flexible generator developed from electrospun CPB/PVDF films are significantly enhanced compared with neat PVDF film, with the maximum Voc value 8.4 times higher; while the measurements on the microscopic piezoelectric responses unambiguously reveal that the increased polar phase mainly contributes to the enhanced electromechanical coupling. The functions of CPB/PVDF film as physiological signals monitoring sensor have been performed, demonstrating its potential applications as flexible piezoelectric generator and wearable health monitoring electronics.
{"title":"Enhanced electromechanical conversion via in situ grown CsPbBr3 nanoparticles/poly(vinylidene fluoride) fibers for physiological signal monitoring","authors":"Xindi Sun, Fengyuan Zhang, Lingyu Zhang, Guimin Liu, Yalong Wang, Yao Wang, Yuan Deng","doi":"10.20517/ss.2021.21","DOIUrl":"https://doi.org/10.20517/ss.2021.21","url":null,"abstract":"Mechanical energy conversion based on piezoelectric principle has received much attention due to its promising applications in sustainable power supply systems and sensor technology. Ferroelectric poly(vinylidene fluoride) (PVDF) combines the advantages of both good electromechanical coupling and easy processability, yet the low piezoelectric coefficient limits its output performances thus cannot meet the increasing requirements for power generation and sensing. Here, inorganic metal halide perovskite CsPbBr3 (CPB) nanoparticles have been incorporated into the PVDF fibers via electrospinning technique, where an in situ crystallization and growth process of CPB nanoparticles have been established. Meanwhile, both the CPB nanoparticles and PVDF fibers are poled by the electric field during electrospinning process, which promotes the formation of polar phase of PVDF and the distortion of CPB lattice, resulting in greatly enhanced piezoelectric performances of CPB/PVDF composites. The output performances under external force of the flexible generator developed from electrospun CPB/PVDF films are significantly enhanced compared with neat PVDF film, with the maximum Voc value 8.4 times higher; while the measurements on the microscopic piezoelectric responses unambiguously reveal that the increased polar phase mainly contributes to the enhanced electromechanical coupling. The functions of CPB/PVDF film as physiological signals monitoring sensor have been performed, demonstrating its potential applications as flexible piezoelectric generator and wearable health monitoring electronics.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67660006","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}
Xi Zhang, Xiaolin Li, Xusheng Wang, Lin Yuan, Jing Ye, Xin Wang, Hualin Deng, Bo Wen, Dong-feng Diao
With the increasing popularity of wearable devices, lightweight electronic skin (e-skin) has attracted significant attention. However, current fabrication technologies make it difficult to directly fabricate sensing materials on flexible substrates at low temperatures. Hence, we propose a flexible graphene nanosheet-embedded carbon (F-GNEC) film, which is directly grown on a flexible substrate using an electron cyclotron resonance low-temperature sputtering system. The direct batch manufacturing of e-skin is obtained by the unique plasma generation mode of electron cyclotron resonance and the polariton energy transfer mode between the plasma and substrate surface. The F-GNEC film contains a large number of graphene nanosheets grown vertically and the graphene edges can serve as electron capture centers, thereby enabling the multi-response properties. We achieve a high gauge factor of 14,699 under a tensile strain of ε = 0.5% and the changing rate of the resistance reaches to 113.2% when the e-skin is bent to 120°. Furthermore, the e-skin achieves a photocurrent of 1.2 μA under 532 nm laser illumination. The F-GNEC film exhibits a sensitive temperature response and achieves a coefficient of -0.58%/°C in a wide temperature range (30-100 °C). The directly fabricated F-GNEC film-based e-skin is stable and firm and exhibits multi-response detection capabilities, which enable its potential application in virtual reality technology and flexible robots.
{"title":"Direct fabrication of high-performance multi-response e-skin based on a graphene nanosheet film","authors":"Xi Zhang, Xiaolin Li, Xusheng Wang, Lin Yuan, Jing Ye, Xin Wang, Hualin Deng, Bo Wen, Dong-feng Diao","doi":"10.20517/ss.2022.18","DOIUrl":"https://doi.org/10.20517/ss.2022.18","url":null,"abstract":"With the increasing popularity of wearable devices, lightweight electronic skin (e-skin) has attracted significant attention. However, current fabrication technologies make it difficult to directly fabricate sensing materials on flexible substrates at low temperatures. Hence, we propose a flexible graphene nanosheet-embedded carbon (F-GNEC) film, which is directly grown on a flexible substrate using an electron cyclotron resonance low-temperature sputtering system. The direct batch manufacturing of e-skin is obtained by the unique plasma generation mode of electron cyclotron resonance and the polariton energy transfer mode between the plasma and substrate surface. The F-GNEC film contains a large number of graphene nanosheets grown vertically and the graphene edges can serve as electron capture centers, thereby enabling the multi-response properties. We achieve a high gauge factor of 14,699 under a tensile strain of ε = 0.5% and the changing rate of the resistance reaches to 113.2% when the e-skin is bent to 120°. Furthermore, the e-skin achieves a photocurrent of 1.2 μA under 532 nm laser illumination. The F-GNEC film exhibits a sensitive temperature response and achieves a coefficient of -0.58%/°C in a wide temperature range (30-100 °C). The directly fabricated F-GNEC film-based e-skin is stable and firm and exhibits multi-response detection capabilities, which enable its potential application in virtual reality technology and flexible robots.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67660115","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}
Zhao Wang, H. Zhou, Bohui Zheng, Yang Gao, Hongli Zhang, Xilang Jin, Gai Zhang, Aijie Ma
Although soft electronic materials are of significant importance for flexible electronic devices, most of them are derived from commercial polymer elastomers, such as polydimethylsiloxane, polyurethane and Ecoflex. In this work, citric acid-based degradable polyester elastomers are prepared by a melt polycondensation process, utilizing citric acid, 1,8-octanediol and poly(ethylene glycol) (PEG) as monomers. Furthermore, poly(1,8-octanediol citrate acid) (POC)-PEG/silver nanowire (AgNW) conductive polyester elastomers (CPEs) are prepared by introducing a AgNW layer on the surface of the POC-PEG films. Scanning electron microscopy images reveal that the thickness of the AgNW layer is on the scale of several micrometers and the AgNWs form a continuous conductive network. Upon mechanical stimuli, POC-PEG exhibits recoverable deformation and induces variation in the AgNW conductive network, resulting in a conversion of strain to detectable resistance. When tensile strain is applied, the POC-PEG/AgNW CPEs achieve a gauge factor of 231.6, a response range of 0%-50%, a low response time of 35 ms and high stability. Moreover, the POC-10PEG/AgNW CPE also responds to bending deformation with a gauge factor of 3667.5, a response range of 0%-8.4%, a low response time of 62 ms and high stability. On the basis of strain sensitivity, wireless sensors are further assembled by integrating the POC-PEG/AgNW CPEs into a Bluetooth signal transmission system. Various human motions and physiological activities are successfully monitored using the wireless sensors. The results demonstrate that degradable citric acid-based polyester elastomers/AgNW CPEs are promising materials for next-generation sustainable and flexible electronic devices.
{"title":"Citric acid-based degradable polyester elastomers coated with silver nanowires for sustainable soft sensors","authors":"Zhao Wang, H. Zhou, Bohui Zheng, Yang Gao, Hongli Zhang, Xilang Jin, Gai Zhang, Aijie Ma","doi":"10.20517/ss.2022.14","DOIUrl":"https://doi.org/10.20517/ss.2022.14","url":null,"abstract":"Although soft electronic materials are of significant importance for flexible electronic devices, most of them are derived from commercial polymer elastomers, such as polydimethylsiloxane, polyurethane and Ecoflex. In this work, citric acid-based degradable polyester elastomers are prepared by a melt polycondensation process, utilizing citric acid, 1,8-octanediol and poly(ethylene glycol) (PEG) as monomers. Furthermore, poly(1,8-octanediol citrate acid) (POC)-PEG/silver nanowire (AgNW) conductive polyester elastomers (CPEs) are prepared by introducing a AgNW layer on the surface of the POC-PEG films. Scanning electron microscopy images reveal that the thickness of the AgNW layer is on the scale of several micrometers and the AgNWs form a continuous conductive network. Upon mechanical stimuli, POC-PEG exhibits recoverable deformation and induces variation in the AgNW conductive network, resulting in a conversion of strain to detectable resistance. When tensile strain is applied, the POC-PEG/AgNW CPEs achieve a gauge factor of 231.6, a response range of 0%-50%, a low response time of 35 ms and high stability. Moreover, the POC-10PEG/AgNW CPE also responds to bending deformation with a gauge factor of 3667.5, a response range of 0%-8.4%, a low response time of 62 ms and high stability. On the basis of strain sensitivity, wireless sensors are further assembled by integrating the POC-PEG/AgNW CPEs into a Bluetooth signal transmission system. Various human motions and physiological activities are successfully monitored using the wireless sensors. The results demonstrate that degradable citric acid-based polyester elastomers/AgNW CPEs are promising materials for next-generation sustainable and flexible electronic devices.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67660506","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}
Jingwen Pan, Kehan Chen, Wenqiang Zhang, Lin Feng, Deyuan Zhang
Microfluidic technology has potential advantages in the complex manipulation of microfluidics on small-sized chips. However, it is difficult to integrate microvalves with complex flow channel structures, and this has limited the miniaturization of microfluidic systems and their portable applications. Light-responsive hydrogel (LRH) materials can rapidly change their volume under laser irradiation and can be used to prepare flexible microvalves to realize the integrated control of microfluidics. A simple fabrication method for an LRH microvalve on a microfluidic chip is proposed. The microspheres, as control elements of the microvalve based on an LRH modified with Laponite RD nanoclay and ferriferous oxide (Fe3O4) nanoparticles, are prepared through a T-shaped flow channel. The microvalve is assembled on the microfluidic chip with a normally closed circulation channel. The open/close performance of the microvalve is represented by the color change of the photonic crystal material. The results show that the LRH microspheres shrink and the flow channel opens after laser irradiation for 2 s. After stopping the laser at 18 s, the valve core swells and the flow channel closes.
{"title":"Fabrication method and performance of a light-responsive hydrogel microvalve in a microfluidic chip","authors":"Jingwen Pan, Kehan Chen, Wenqiang Zhang, Lin Feng, Deyuan Zhang","doi":"10.20517/ss.2022.03","DOIUrl":"https://doi.org/10.20517/ss.2022.03","url":null,"abstract":"Microfluidic technology has potential advantages in the complex manipulation of microfluidics on small-sized chips. However, it is difficult to integrate microvalves with complex flow channel structures, and this has limited the miniaturization of microfluidic systems and their portable applications. Light-responsive hydrogel (LRH) materials can rapidly change their volume under laser irradiation and can be used to prepare flexible microvalves to realize the integrated control of microfluidics. A simple fabrication method for an LRH microvalve on a microfluidic chip is proposed. The microspheres, as control elements of the microvalve based on an LRH modified with Laponite RD nanoclay and ferriferous oxide (Fe3O4) nanoparticles, are prepared through a T-shaped flow channel. The microvalve is assembled on the microfluidic chip with a normally closed circulation channel. The open/close performance of the microvalve is represented by the color change of the photonic crystal material. The results show that the LRH microspheres shrink and the flow channel opens after laser irradiation for 2 s. After stopping the laser at 18 s, the valve core swells and the flow channel closes.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67660047","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}
Tactile feedback is of great significance for amputees to improve the controllability of prosthetic hands and obtain tactile information regarding the interacting objects, which remains a significant challenge for neuroprosthetic hands. In this study, we present a method to restore finger-specific tactile sensations on the projected finger map of a unilateral forearm amputee with a sensory soft neuroprosthetic hand through electrotactile stimulation. On this basis, five soft touch sensors embedded in the fingertips are first adopted to measure the pressure changes of the soft neuroprosthetic hand with the touched objects. The measured pressure information is then accordingly encoded into electrotactile stimulation patterns to trigger an electrical stimulator that outputs programmable electrical pulses on the projected finger map of the amputee. In this manner, the finger tactile sensation can be elicited, which can help the amputee to distinguish the finger press state and discriminate the curvature and hardness of the touched objects. Experimental results show that, based on the different stimulation regions, the amputee subject can instantaneously distinguish the tactile sensation of a single finger or multiple fingers with an accuracy of 98.57% and 91.71%, respectively. By programming the frequencies of the electrical pulses, the amputee subject can successfully discriminate the touching objects with different curvatures and hardnesses with an accuracy of 97.26% and 97.93%, respectively. Finally, we demonstrate that the amputee subject can achieve closed-loop control of the sensory soft neuroprosthetic hand by integrating a myoelectric control interface and electrotactile feedback to achieve multilevel perception.
{"title":"Restoring finger-specific tactile sensations with a sensory soft neuroprosthetic hand through electrotactile stimulation","authors":"Haipeng Xu, G. Chai, Ningbin Zhang, G. Gu","doi":"10.20517/ss.2022.17","DOIUrl":"https://doi.org/10.20517/ss.2022.17","url":null,"abstract":"Tactile feedback is of great significance for amputees to improve the controllability of prosthetic hands and obtain tactile information regarding the interacting objects, which remains a significant challenge for neuroprosthetic hands. In this study, we present a method to restore finger-specific tactile sensations on the projected finger map of a unilateral forearm amputee with a sensory soft neuroprosthetic hand through electrotactile stimulation. On this basis, five soft touch sensors embedded in the fingertips are first adopted to measure the pressure changes of the soft neuroprosthetic hand with the touched objects. The measured pressure information is then accordingly encoded into electrotactile stimulation patterns to trigger an electrical stimulator that outputs programmable electrical pulses on the projected finger map of the amputee. In this manner, the finger tactile sensation can be elicited, which can help the amputee to distinguish the finger press state and discriminate the curvature and hardness of the touched objects. Experimental results show that, based on the different stimulation regions, the amputee subject can instantaneously distinguish the tactile sensation of a single finger or multiple fingers with an accuracy of 98.57% and 91.71%, respectively. By programming the frequencies of the electrical pulses, the amputee subject can successfully discriminate the touching objects with different curvatures and hardnesses with an accuracy of 97.26% and 97.93%, respectively. Finally, we demonstrate that the amputee subject can achieve closed-loop control of the sensory soft neuroprosthetic hand by integrating a myoelectric control interface and electrotactile feedback to achieve multilevel perception.","PeriodicalId":74837,"journal":{"name":"Soft science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67660073","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}