Flexible tactile sensors have broad applications in human physiological monitoring,robotic operation and human-machine interaction.However,the research of wearable and flexible tactile sensors with high sensitivity,wi...Flexible tactile sensors have broad applications in human physiological monitoring,robotic operation and human-machine interaction.However,the research of wearable and flexible tactile sensors with high sensitivity,wide sensing range and ability to detect three-dimensional(3D)force is still very challenging.Herein,a flexible tactile electronic skin sensor based on carbon nanotubes(CNTs)/polydimethylsiloxane(PDMS)nanocomposites is presented for 3D contact force detection.The 3D forces were acquired from combination of four specially designed cells in a sensing element.Contributed from the double-sided rough porous structure and specific surface morphology of nanocomposites,the piezoresistive sensor possesses high sensitivity of 12.1 kPa?1 within the range of 600 Pa and 0.68 kPa?1 in the regime exceeding 1 kPa for normal pressure,as well as 59.9 N?1 in the scope of<0.05 N and>2.3 N?1 in the region of<0.6 N for tangential force with ultra-low response time of 3.1 ms.In addition,multi-functional detection in human body monitoring was employed with single sensing cell and the sensor array was integrated into a robotic arm for objects grasping control,indicating the capacities in intelligent robot applications.展开更多
CONSPECTUS:Piezoionic skin sensors are one kind of artificial electrical skin that can output sensing signals in response to external strain or stress stimulus with merits of flexibility,lightness,scalability,and high...CONSPECTUS:Piezoionic skin sensors are one kind of artificial electrical skin that can output sensing signals in response to external strain or stress stimulus with merits of flexibility,lightness,scalability,and high sensitivity.They have been emerging as an important platform in artificial intelligence,such as in smart healthcare,bionic robotics,and microelectromechanical systems.Piezoionic sensors are typically composed of an electrolyte laminated with symmetric electrodes and are based on ion migration and redistribution under a gradient strain or stress field.However,existing challenges significantly impede the sensing performance of piezoionic sensors,including the low electromechanical coupling efficiency of the electrode materials,instability of electrolyte materials,and strain-induced interface separation of sensor interfaces.In recent years,our group and collaborators have made attempts addressing the as-mentioned critical challenges in order to achieve flexible piezoionic sensors with satisfying performance for wearable smart applications.First,for the electromechanical coupling efficiency of electrode materials,we have developed various electrode materials with highly efficient ion storage and transfer,such as graphdiyne,quinone composites,and graphitic carbon nitride.These materials present superior electrical and mechanical properties with enhanced electromechanical coupling efficiency.Second,in order to improve the stability of electrolytes,especially in an air environment,we have developed ionogel electrolytes instead of conventional hydrogel electrolytes.Ionogels contain highly stable ionic liquids,which effectively improve the air stability of sensor electrolytes,and the sensing properties of devices are preserved even after several months.Third,with regard to sensor interface separation,we have engineered stable material interfaces for piezoionic sensors with elaborate structures.The as-designed tree-root-inspired interfaces show high mechanical stability under various flexible conditions,and the piezoionic sensors display negligible performance deterioration under thousands of bending cycles in an ambient environment.Finally,we have obtained flexible piezoionic sensors and studied their practical applications,such as wearable electronics,health monitoring,and smart detections.For example,we have realized the accurate detection of blood pressure based on an out-of-plane piezoionic mechanism.This innovative technique completely avoids the cuff issue that commercial sphygmomanometers have.Moreover,we have developed multifinger-touch piezoionic sensor arrays for effective braille recognition,which have the potential to eliminate communication barriers with sight-impaired people.Human voices can be easily differentiated by detecting vocal-cord vibrations based on captured sensing signals with obviously different patterns.This smart technique is promising for extended and applied use in virtual reality technology.Lastly,a perspective on existing challenges of piezoionic sensors is highlighted to set a clear direction for future research,including low-cost material synthesis,the mass production of flexible sensors,and healthcare sensor products.展开更多
This paper reports a novel technique for fabrication of a flexible skin with a temperature sensor array (40×1 sensors). A simplified MEMS technology using platinum resistors as sensing materials, which are sandwi...This paper reports a novel technique for fabrication of a flexible skin with a temperature sensor array (40×1 sensors). A simplified MEMS technology using platinum resistors as sensing materials, which are sandwiched between two polyimide layers as flexible substrates is developed. The two polyimide layers are deposited on top of a thin aluminum layer, which serves as a sacrificial layer such that the flexible skin can be released by metal etching and peeled off easily. The flexible skin with a temperature sensor array has a high mechanical flexibility and can be handily attached on a highly curved surface to detect tiny temperature distribution inside a small area. The sensor array shows a linear output and has a sensitivity of 7.5 mV/°C (prior to amplifiers) at a drive current of 1 mA. To demonstrate its applications, two examples have been demonstrated, including measurement of temperature distribution around a micro heater of a micro PCR (polymerase chain reaction) chip for DNA amplification and detection of separation point for flow over a circular cylinder. The development of the flexible skin with a temperature sensor array may be crucial for measuring temperature distribution on any curved surface in the fields of aerodynamics, space exploration, auto making and biomedical applications etc.展开更多
Skin is the largest organ of the human body and can perceive and respond to complex environmental stimulations.Recently,the development of electronic skin(E-skin)for the mimicry of the human sensory system has drawn g...Skin is the largest organ of the human body and can perceive and respond to complex environmental stimulations.Recently,the development of electronic skin(E-skin)for the mimicry of the human sensory system has drawn great attention due to its potential applications in wearable human health monitoring and care systems,advanced robotics,artificial intelligence,and human-machine interfaces.Tactile sense is one of the most important senses of human skin that has attracted special attention.The ability to obtain unique functions using diverse assembly processible methods has rapidly advanced the use of graphene,the most celebrated two-dimensional material,in electronic tactile sensing devices.With a special emphasis on the works achieved since 2016,this review begins with the assembly and modification of graphene materials and then critically and comprehensively summarizes the most advanced material assembly methods,device construction technologies and signal characterization approaches in pressure and strain detection based on graphene and its derivative materials.This review emphasizes on:(1)the underlying working principles of these types of sensors and the unique roles and advantages of graphene materials;(2)state-of-the-art protocols recently developed for high-performance tactile sensing,including representative examples;and(3)perspectives and current challenges for graphene-based tactile sensors in E-skin applications.A summary of these cutting-edge developments intends to provide readers with a deep understanding of the future design of high-quality tactile sensing devices and paves a path for their future commercial applications in the field of E-skin.展开更多
This study proposed a new yarn-like strain sensor on the basis of the braided skin-core rope,and investigated the effect of braiding structures on the sensing properties of sensors.The morphology and electromechanical...This study proposed a new yarn-like strain sensor on the basis of the braided skin-core rope,and investigated the effect of braiding structures on the sensing properties of sensors.The morphology and electromechanical properties of the strain sensor with different braiding structures were compared and evaluated.The results show that the sensing performance of the sensor from a braided skin-core rope depends on both the number of yarns in braiding and the metallized process of braided rope.Generally,the present stretchable skin-core rope-based sensor provides a basis for the formation of a highly sensitive sensing structure.展开更多
Placement and wiring of vast amount of sensor elements on the 3-dimensionally configured robot sur-face to form soft sensor skin is very difficult with the traditional technology. In this paper we propose a new method...Placement and wiring of vast amount of sensor elements on the 3-dimensionally configured robot sur-face to form soft sensor skin is very difficult with the traditional technology. In this paper we propose a new method to realize such a skin.By implanting infrared sensors array in an elastic body, we obtain an elastic and tough sensor skin that can be shaped freely.The developed sensor skin is a large-area, flexi-ble array of infrared sensors with data processing capabilities.Depending on the skin electronics, it en-dows its carrier with an ability to sense its surroundings.The structure, the method of infrared sensor sig-nal processing, and basic experiments of sensor skin are presented. The validity of the infrared sensor skin is investigated by preliminary obstacle avoidance trial.展开更多
We present a theoretic model to calculate skin depths and eddy-current power losses for a magnetic position sensor. Eddy-current, arised from the operation of an alternating-current excitation, induces secondary curre...We present a theoretic model to calculate skin depths and eddy-current power losses for a magnetic position sensor. Eddy-current, arised from the operation of an alternating-current excitation, induces secondary currents and fields between magnetic material and magnetic position sensor. In this paper, a magnetic position sensor system is simplified to be an outer-winding coil along the axial direction of a low carbon steel bar. The analytical model is derived from basic field and circuit theory considering a linear approximation for a nonlinear permeability. Thus the skin depths and eddy-current power losses from the model in eddy-current modeling techniques at various frequencies of an excited current source can be calculated. The proposed configuration is capable of predicting the skin depths and eddy-current power losses for a magnetic position sensor and has a consistence with experiments.展开更多
Transparent, flexible electronic skin holds a wide range of applications in robotics, humanmachine interfaces, artificial intelligence, prosthetics, and health monitoring. Silver nanowire are mechanically flexible and...Transparent, flexible electronic skin holds a wide range of applications in robotics, humanmachine interfaces, artificial intelligence, prosthetics, and health monitoring. Silver nanowire are mechanically flexible and robust, which exhibit great potential in transparent and electricconducting thin film. Herein, we report on a silver-nanowire spray-coating and electrodemicrostructure replicating strategy to construct a transparent, flexible, and sensitive electronic skin device. The electronic skin device shows highly sensitive piezo-capacitance response to pressure. It is found that micropatterning the surface of dielectric layer polyurethane elastomer by replicating from microstructures of natural-existing surfaces such as lotus leaf, silk, and frosted glass can greatly enhance the piezo-capacitance performance of the device. The microstructured pressure sensors based on silver nanowire exhibit good transparency, excellent flexibility, wide pressure detection range （0-150 kPa）, and high sensitivity （1.28 kPa-1）.展开更多
基金funding from National Natural Science Foundation of China(NSFC Nos.61774157,81771388,61874121,and 61874012)Beijing Natural Science Foundation(No.4182075)the Capital Science and Technology Conditions Platform Project(Project ID:Z181100009518014).
文摘Flexible tactile sensors have broad applications in human physiological monitoring,robotic operation and human-machine interaction.However,the research of wearable and flexible tactile sensors with high sensitivity,wide sensing range and ability to detect three-dimensional(3D)force is still very challenging.Herein,a flexible tactile electronic skin sensor based on carbon nanotubes(CNTs)/polydimethylsiloxane(PDMS)nanocomposites is presented for 3D contact force detection.The 3D forces were acquired from combination of four specially designed cells in a sensing element.Contributed from the double-sided rough porous structure and specific surface morphology of nanocomposites,the piezoresistive sensor possesses high sensitivity of 12.1 kPa?1 within the range of 600 Pa and 0.68 kPa?1 in the regime exceeding 1 kPa for normal pressure,as well as 59.9 N?1 in the scope of<0.05 N and>2.3 N?1 in the region of<0.6 N for tangential force with ultra-low response time of 3.1 ms.In addition,multi-functional detection in human body monitoring was employed with single sensing cell and the sensor array was integrated into a robotic arm for objects grasping control,indicating the capacities in intelligent robot applications.
基金supported by startup funding from Soochow University,the Jiangsu Specially-Appointed Professor Funding,the National Natural Science Foundation of China(62404148)the Natural Science Foundation of Jiangsu Province(BK20220505)+1 种基金the Leading Talents of Innovation and Entrepreneurship of Gusu(ZXL2023191)the Collaborative Innovation Center of Suzhou Nano Science&Technology.
文摘CONSPECTUS:Piezoionic skin sensors are one kind of artificial electrical skin that can output sensing signals in response to external strain or stress stimulus with merits of flexibility,lightness,scalability,and high sensitivity.They have been emerging as an important platform in artificial intelligence,such as in smart healthcare,bionic robotics,and microelectromechanical systems.Piezoionic sensors are typically composed of an electrolyte laminated with symmetric electrodes and are based on ion migration and redistribution under a gradient strain or stress field.However,existing challenges significantly impede the sensing performance of piezoionic sensors,including the low electromechanical coupling efficiency of the electrode materials,instability of electrolyte materials,and strain-induced interface separation of sensor interfaces.In recent years,our group and collaborators have made attempts addressing the as-mentioned critical challenges in order to achieve flexible piezoionic sensors with satisfying performance for wearable smart applications.First,for the electromechanical coupling efficiency of electrode materials,we have developed various electrode materials with highly efficient ion storage and transfer,such as graphdiyne,quinone composites,and graphitic carbon nitride.These materials present superior electrical and mechanical properties with enhanced electromechanical coupling efficiency.Second,in order to improve the stability of electrolytes,especially in an air environment,we have developed ionogel electrolytes instead of conventional hydrogel electrolytes.Ionogels contain highly stable ionic liquids,which effectively improve the air stability of sensor electrolytes,and the sensing properties of devices are preserved even after several months.Third,with regard to sensor interface separation,we have engineered stable material interfaces for piezoionic sensors with elaborate structures.The as-designed tree-root-inspired interfaces show high mechanical stability under various flexible conditions,and the piezoionic sensors display negligible performance deterioration under thousands of bending cycles in an ambient environment.Finally,we have obtained flexible piezoionic sensors and studied their practical applications,such as wearable electronics,health monitoring,and smart detections.For example,we have realized the accurate detection of blood pressure based on an out-of-plane piezoionic mechanism.This innovative technique completely avoids the cuff issue that commercial sphygmomanometers have.Moreover,we have developed multifinger-touch piezoionic sensor arrays for effective braille recognition,which have the potential to eliminate communication barriers with sight-impaired people.Human voices can be easily differentiated by detecting vocal-cord vibrations based on captured sensing signals with obviously different patterns.This smart technique is promising for extended and applied use in virtual reality technology.Lastly,a perspective on existing challenges of piezoionic sensors is highlighted to set a clear direction for future research,including low-cost material synthesis,the mass production of flexible sensors,and healthcare sensor products.
文摘This paper reports a novel technique for fabrication of a flexible skin with a temperature sensor array (40×1 sensors). A simplified MEMS technology using platinum resistors as sensing materials, which are sandwiched between two polyimide layers as flexible substrates is developed. The two polyimide layers are deposited on top of a thin aluminum layer, which serves as a sacrificial layer such that the flexible skin can be released by metal etching and peeled off easily. The flexible skin with a temperature sensor array has a high mechanical flexibility and can be handily attached on a highly curved surface to detect tiny temperature distribution inside a small area. The sensor array shows a linear output and has a sensitivity of 7.5 mV/°C (prior to amplifiers) at a drive current of 1 mA. To demonstrate its applications, two examples have been demonstrated, including measurement of temperature distribution around a micro heater of a micro PCR (polymerase chain reaction) chip for DNA amplification and detection of separation point for flow over a circular cylinder. The development of the flexible skin with a temperature sensor array may be crucial for measuring temperature distribution on any curved surface in the fields of aerodynamics, space exploration, auto making and biomedical applications etc.
基金supported by the National Key Research and Development Program of China(2017YFB0405400)National Natural Science Foundation of China(51732007)+1 种基金Major Innovation Projects in Shandong Province(2018YFJH0503)Natural Science Foundation of Shandong Province(ZR2018BEM010).
文摘Skin is the largest organ of the human body and can perceive and respond to complex environmental stimulations.Recently,the development of electronic skin(E-skin)for the mimicry of the human sensory system has drawn great attention due to its potential applications in wearable human health monitoring and care systems,advanced robotics,artificial intelligence,and human-machine interfaces.Tactile sense is one of the most important senses of human skin that has attracted special attention.The ability to obtain unique functions using diverse assembly processible methods has rapidly advanced the use of graphene,the most celebrated two-dimensional material,in electronic tactile sensing devices.With a special emphasis on the works achieved since 2016,this review begins with the assembly and modification of graphene materials and then critically and comprehensively summarizes the most advanced material assembly methods,device construction technologies and signal characterization approaches in pressure and strain detection based on graphene and its derivative materials.This review emphasizes on:(1)the underlying working principles of these types of sensors and the unique roles and advantages of graphene materials;(2)state-of-the-art protocols recently developed for high-performance tactile sensing,including representative examples;and(3)perspectives and current challenges for graphene-based tactile sensors in E-skin applications.A summary of these cutting-edge developments intends to provide readers with a deep understanding of the future design of high-quality tactile sensing devices and paves a path for their future commercial applications in the field of E-skin.
基金Biomedical Textile Material Science and Technology,China(111 Project)(No.B07024)
文摘This study proposed a new yarn-like strain sensor on the basis of the braided skin-core rope,and investigated the effect of braiding structures on the sensing properties of sensors.The morphology and electromechanical properties of the strain sensor with different braiding structures were compared and evaluated.The results show that the sensing performance of the sensor from a braided skin-core rope depends on both the number of yarns in braiding and the metallized process of braided rope.Generally,the present stretchable skin-core rope-based sensor provides a basis for the formation of a highly sensitive sensing structure.
基金Supported by the National Natural Science Foundation of China （No.50105002）.
文摘Placement and wiring of vast amount of sensor elements on the 3-dimensionally configured robot sur-face to form soft sensor skin is very difficult with the traditional technology. In this paper we propose a new method to realize such a skin.By implanting infrared sensors array in an elastic body, we obtain an elastic and tough sensor skin that can be shaped freely.The developed sensor skin is a large-area, flexi-ble array of infrared sensors with data processing capabilities.Depending on the skin electronics, it en-dows its carrier with an ability to sense its surroundings.The structure, the method of infrared sensor sig-nal processing, and basic experiments of sensor skin are presented. The validity of the infrared sensor skin is investigated by preliminary obstacle avoidance trial.
文摘We present a theoretic model to calculate skin depths and eddy-current power losses for a magnetic position sensor. Eddy-current, arised from the operation of an alternating-current excitation, induces secondary currents and fields between magnetic material and magnetic position sensor. In this paper, a magnetic position sensor system is simplified to be an outer-winding coil along the axial direction of a low carbon steel bar. The analytical model is derived from basic field and circuit theory considering a linear approximation for a nonlinear permeability. Thus the skin depths and eddy-current power losses from the model in eddy-current modeling techniques at various frequencies of an excited current source can be calculated. The proposed configuration is capable of predicting the skin depths and eddy-current power losses for a magnetic position sensor and has a consistence with experiments.
基金This work was supported by the National Natural Science Foundation of China （No.61674078） and Dongrun- Yau Science Silver Award （Chemistry）.
文摘Transparent, flexible electronic skin holds a wide range of applications in robotics, humanmachine interfaces, artificial intelligence, prosthetics, and health monitoring. Silver nanowire are mechanically flexible and robust, which exhibit great potential in transparent and electricconducting thin film. Herein, we report on a silver-nanowire spray-coating and electrodemicrostructure replicating strategy to construct a transparent, flexible, and sensitive electronic skin device. The electronic skin device shows highly sensitive piezo-capacitance response to pressure. It is found that micropatterning the surface of dielectric layer polyurethane elastomer by replicating from microstructures of natural-existing surfaces such as lotus leaf, silk, and frosted glass can greatly enhance the piezo-capacitance performance of the device. The microstructured pressure sensors based on silver nanowire exhibit good transparency, excellent flexibility, wide pressure detection range （0-150 kPa）, and high sensitivity （1.28 kPa-1）.
