Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors c...Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.展开更多
Pacinian Corpuscle(PC)is the largest tactile vibration receptor in mammalian skin,with a layered structure that enables signal amplification and high-pass filtering functions.Modern robots feature vibro-tactile sensor...Pacinian Corpuscle(PC)is the largest tactile vibration receptor in mammalian skin,with a layered structure that enables signal amplification and high-pass filtering functions.Modern robots feature vibro-tactile sensors with excellent mechanical properties and fine resolution,but these sensors are prone to low-frequency noise interference when detecting high-frequency vibrations.In this study,a bionic PC with a longitudinally decreasing dynamic fractal structure is proposed.By creating a lumped parameter model of the PC’s layered structure,the bionic PC made of gelatin-chitosan based hydrogel can achieve high-pass filtering and specific frequency band signal amplification without requiring back-end circuits.The experimental results demonstrate that the bionic PC retains the structural characteristics of a natural PC,and the influence of structural factors,such as the number of layers in its shell,on filtration characteristics is explored.Additionally,a vibration source positioning experiment was conducted to simulate the earthquake sensing abilities of elephants.This natural structural design simplifies the filter circuit,is low-cost,cost-effective,stable in performance,and reduces redundancy in the robot’s signal circuit.Integrating this technology with robots can enhance their environmental perception,thereby improving the safety of interactions.展开更多
Piezoelectric and triboelectric effects are of growing interest for facilitating high-sensitivity and self-powered tactile sensor applications.The working principles of piezoelectric and triboelectric nanogenerators p...Piezoelectric and triboelectric effects are of growing interest for facilitating high-sensitivity and self-powered tactile sensor applications.The working principles of piezoelectric and triboelectric nanogenerators provide strategies for enhancing output voltage signals to achieve high sensitivity.Increasing the piezoelectric constant and surface triboelectric charge density are key factors in this enhancement.Methods such as annealing processes,doping techniques,grain orientation controls,crystallinity controls,and composite structures can effectively enhance the piezoelectric constant.For increasing triboelectric output,surface plasma treatment,charge injection,microstructuring,control of dielectric constant,and structural modification are effective methods.The fabrication methods present significant opportunities in tactile sensor applications.This review article summarizes the overall piezoelectric and triboelectric fabrication processes from materials to device aspects.It highlights applications in pressure,touch,bending,texture,distance,and material recognition sensors.The conclusion section addresses challenges and research opportunities,such as limited flexibility,stretchability,decoupling from multi-stimuli,multifunctional sensors,and data processing.展开更多
Human skin,through its complex mechanoreceptor system,possesses the exceptional ability to finely perceive and dif-ferentiate multimodal mechanical stimuli,forming the biological foundation for dexterous manipulation,...Human skin,through its complex mechanoreceptor system,possesses the exceptional ability to finely perceive and dif-ferentiate multimodal mechanical stimuli,forming the biological foundation for dexterous manipulation,environmental explo-ration,and tactile perception.Tactile sensors that emulate this sensory capability,particularly in the detection,decoupling,and application of normal and shear forces,have made significant strides in recent years.This review comprehensively examines the latest research advancements in tactile sensors for normal and shear force sensing,delving into the design and decoupling methods of multi-unit structures,multilayer encapsulation structures,and bionic structures.It analyzes the advantages and disadvantages of various sensing principles,including piezoresistive,capacitive,and self-powered mechanisms,and evalu-ates their application potential in health monitoring,robotics,wearable devices,smart prosthetics,and human-machine interaction.By systematically summarizing current research progress and technical challenges,this review aims to provide forward-looking insights into future research directions,driving the development of electronic skin technology to ultimately achieve tactile perception capabilities comparable to human skin.展开更多
As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progres...As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented.展开更多
Eased on the mechanism of temperature tactile sensing of human finger,a heat flux tactile sensor com- posed of a thermostat module and a heat flux sensor is designed to identify material thermal properties. The ther- ...Eased on the mechanism of temperature tactile sensing of human finger,a heat flux tactile sensor com- posed of a thermostat module and a heat flux sensor is designed to identify material thermal properties. The ther- mostat module maintains the sensor temperature invariable, and the heat flux sensor（Peltier device） detects the heat flux temperature difference between the thermostat module and the object surface. Two different modes of the heat flux tactile sensor are proposed, and they are simulated and experimented for different material objects. The results indicate that the heat flux tactile sensor can effectively identify different thermal properties.展开更多
Traditional triboelectric tactile sensors based on solid–solid interface have illustrated promising application prospects through optimization approach.However,the poor sensitivity and reliability caused by hard cont...Traditional triboelectric tactile sensors based on solid–solid interface have illustrated promising application prospects through optimization approach.However,the poor sensitivity and reliability caused by hard contact-electrification still poses challenges for the practical applications.In this work,a liquid–solid interface ferrofluid-based triboelectric tactile sensor(FTTS)with ultrahigh sensitivity is proposed.Relying on the fluidity and magnetism of ferrofluid,the topography of microstructure can be flexibly adjusted by directly employing ferrofluid as triboelectric material and controlling the position of outward magnet.To date,an ultrahigh sensitivity of 21.48 k Pa;for the triboelectric sensors can be achieved due to the high spike microstructure,low Young’s modulus of ferrofluid and efficient solid–liquid interface contact-electrification.The detection limit of FTTS of 1.25 Pa with a wide detection range to 390 k Pa was also obtained.In addition,the oleophobic property between ferrofluid and poly-tetra-fluoro-ethylene triboelectric layer can greatly reduce the wear and tear,resulting in the great improvement of stability.Finally,a strategy for personalized password lock with high security level has been demonstrated,illustrating a great perspective for practical application in smart home,artificial intelligence,Internet of things,etc.展开更多
We report the first attempt to model the contacts of an ionic polymer metal composite（IPMC） based tactile sensor. The tactile sensor comprises an IPMC actuator, an IPMC sensor and the target to be detected. The syst...We report the first attempt to model the contacts of an ionic polymer metal composite（IPMC） based tactile sensor. The tactile sensor comprises an IPMC actuator, an IPMC sensor and the target to be detected. The system makes use of multiple contacts to work： the actuator comes into contact with the sensor and pushes the movement of sensor; the contact between the sensor and the object detects the existence and the stiffness of the target. We integrate modeling of various physical processes involved in IPMC devices to form a simulation scheme. An iteration and optimization strategy is also described to correlate the experimental and simulation results of an IPMC bending actuator to identify the two key parameters used in electromechanical transduction. Modeling the multiple contacts will aid the design and optimization of such IPMC based soft robotics.展开更多
In the underwater environment, many visual sensors don’t work, and many sensors which work well for robots working in space or on land can not be used underwater. Therefore, an optical fiber slide tactile sensor was ...In the underwater environment, many visual sensors don’t work, and many sensors which work well for robots working in space or on land can not be used underwater. Therefore, an optical fiber slide tactile sensor was designed based on the inner modulation mechanism of optical fibers. The principles and structure of the sensor are explained in detail. Its static and dynamic characteristics were analyzed theoretically and then simulated. A dynamic characteristic model was built and the simulation made using the GA based neural network. In order to improve sensor response, the recognition model of the sensor was designed based on the ‘inverse solution’ principle of neural networks, increasing the control precision and the sensitivity of the manipulator.展开更多
Because of the special underwater environment, many sensors used well in robots working in space or on the land can not be used in the underwater. So an optical fiber type slide tactile sensor is designed by the inner...Because of the special underwater environment, many sensors used well in robots working in space or on the land can not be used in the underwater. So an optical fiber type slide tactile sensor is designed by the inner modulation mechanism of the intensity type optical fiber. The principle and structure of the sensor are introduced in detail. The static and dynamic characteristics are analyzed theoretically and experimentally. The dynamic characteristic model is built and the simulation is made by using genetic algorithm based on neural network. In order to use the sensor perfectly, the recognition model of the sensor is built on the basis of the principle of “inverse solution” using neural networks. The control precision and sensitivity of the manipulator are improved.展开更多
This paper reports the design and fabrication of a MEMS-based ZnO piezoelectric tactile sensor,which can be integrated on to the endoscopic grasper used in minimally invasive surgery (MIS).The sensor includes a silico...This paper reports the design and fabrication of a MEMS-based ZnO piezoelectric tactile sensor,which can be integrated on to the endoscopic grasper used in minimally invasive surgery (MIS).The sensor includes a silicon substrate, platinum bottom electrode,platinum top electrode,and a ZnO piezoelectric thin film,which is sandwiched between the two-electrode layers.The sensitivity of the micro-force sensor is analyzed in theory and the sensor exhibits high sensitivity about 7pc/uN.The application of this tactile sensor to MIS will allow the surgeon feeling the touch force between the endoscopic grasper and tissue in real-time,and manipulating the tissue safely.展开更多
In the research of 2D flexible tactile sensor matrix,pressure-sensitive conductive rubber was developed and tested in which carbon black was used as its conductive phase and silicon rubber as its matrix layer.Experime...In the research of 2D flexible tactile sensor matrix,pressure-sensitive conductive rubber was developed and tested in which carbon black was used as its conductive phase and silicon rubber as its matrix layer.Experiments were undertaken and the resultant data were used for its piezoresistive characteristics investigation for two kinds of electrode connection configurations,the surface directive connection and embedded connection.It is found that due to the rather strong nonlinearity of the piezoresistive characteristic curves obtained,a higher correlation relationship can be obtained by means of quadratic polynomial fitting.It also showed that the embedded electrode assembling has higher fitting accuracy while the surface directive connection has better mechanical sensitivity.展开更多
Tactile sensors are one of the core components for intelligent robots to realize human-like tactile sensing functions.For the application scenarios of material classification and roughness recognition,an enhanced flex...Tactile sensors are one of the core components for intelligent robots to realize human-like tactile sensing functions.For the application scenarios of material classification and roughness recognition,an enhanced flexible triboelectric tactile sensor(FTTS)is proposed in this study.The FTTS is prepared based on a single-electrode triboelectric nanogenerator(SETENG),which generates the corresponding electrical signals by coming in contact with objects.To enhance the properties of the SE-TENG,the synergistic enhancement effect on the electrical output of the SE-TENG was explored by controlling the addition ratio of MXene and Carboxylated cellulose nanofibers(CNF-C).The charge-trapping mechanism of the chargetrapping layer was analyzed,and the effects of the type and thickness of the charge-trapping layer on the performance of the FTTS were systematically investigated.Inexpensive and simple fabricated braided microstructures were prepared using the template method,which showed the optimum capability in terms of self-cleaning and electrical output performance.With these improvements,the FTTS showed a voltage sensitivity of 2.88 V/10^(4)Pa in the pressure response range of 10-400 kPa,a linearity of 0.993,and a linear trend in the fitting curve.At the same time,the FTTS has a stable response frequency,fast response time,and extreme cycling stability(over 10000 cycles).In addition,in terms of roughness recognition,the FTTS can accurately recognize samples with different surface roughness.In terms of material classification,the accuracy of classifying 11materials with the visual geometry group(VGG)network reaches 96.08%.Based on these findings,FTTS-based tactile sensors offer diverse options in the future direction of electronic skin and tactile sensing.展开更多
Tactile sensors are a potential solution for material identification.However,current potential tactile sensors for material identification are pressed,expensive,and applications-confined.Here we report a clamped-on py...Tactile sensors are a potential solution for material identification.However,current potential tactile sensors for material identification are pressed,expensive,and applications-confined.Here we report a clamped-on pyroelectric tactile sensor on the basis of a ferroelectric Bi_(0.5)Na_(0.5)TiO_(3) material to identify different film materials.The fabricated device exhibits different heat absorption capacities while in contact with different materials,leading to a different temperature change in the ferroelectric material under the same illumination.As a result,the device can recognize different materials by comparing the pyroelectric charge via integrating the obtained current under the same irradiation of 365nmlight-emitting diode.The clamped-on pyroelectric tactile sensor can identify six individual materials with a high accuracy of 98.8%and a fast response of 40 ms.All of the above processes can be accomplished with an intelligent material identification system.The device provides a new solution for material identification and lays a foundation for smart factories and laboratories.展开更多
Intelligent applications,with tactile sensors at their core,represent significant advancement in the field of artificial intelligence.However,achieving perception abilities in tactile sensors that match or exceed huma...Intelligent applications,with tactile sensors at their core,represent significant advancement in the field of artificial intelligence.However,achieving perception abilities in tactile sensors that match or exceed human skin remains a formidable challenge.Consequently,the design and implementation of hierarchical structural materials are considered the optimal solution to this challenge.In contrast to conventional methods,such as complicated lithography and three-dimensional printing,the cost-effective and scalable nature of advanced solution-synthesis methods makes them ideal for preparing diverse tactile sensors with hierarchical structural materials.However,the process and applicability of advanced solution synthesis methods have yet to form a seamless system.Accordingly,the development and intellectualization of tactile sensors based on advanced solution synthesis methods are still in their early stages,and require a comprehensive and systematic review to usher in progress.This study delves into the advantages and disadvantages of various advanced solution synthesis methods,providing detailed insights.Furthermore,the positive effects of hierarchical structural materials constructed using these methods in tactile sensors and their intelligent applications are also discussed in depth.Finally,the challenges and future opportunities faced by this emerging field are summarized.展开更多
In recent years,multi-modal flexible tactile sensors have become an important direction in the development of electronic skin because of their excellent sensitivity,flexibility and wearable properties.In this work,a h...In recent years,multi-modal flexible tactile sensors have become an important direction in the development of electronic skin because of their excellent sensitivity,flexibility and wearable properties.In this work,a humidity-pressure multi-modal flexible sensor based on polypyrrole(PPy)/Ti_(3)C_(2)T_(x) sensitive film packaged with porous polydimethylsiloxane(PDMS)is investigated by combining the sensitive structure generation mechanism of in situ polymerization to achieve the simultaneous detection of humidity and pressure,which has a sensitivity of 89,113.4Ω/%RH in a large humidity range of 0%-97%RH,and response/recovery time of 2.5/1.9 s.The tactile pressure sensing has a high sensitivity,a fast response of 67/52 ms,and a wide detection limit.The device also has excellent performance in terms of stability and repeatability,making it promising for respiratory pattern and motion detection.This work provides a new solution to address the construction of multi-modal tactile sensors with potential applications in the fields of medical health,epidemic prevention.展开更多
This review explores the current state and future prospects of tactile sensing technologies in space robotics,addressing the unique challenges posed by harsh space environments such as extreme temperatures,radiation,m...This review explores the current state and future prospects of tactile sensing technologies in space robotics,addressing the unique challenges posed by harsh space environments such as extreme temperatures,radiation,microgravity,and vacuum conditions,which necessitate specialized sensor designs.We provide a detailed analysis of four primary types of tactile sensors:resistive,capacitive,piezoelectric,and optical,evaluating their operating principles,advantages,limitations,and specific applications in space exploration.Recent advancements in materials science,including the development of radiation-hardened components and flexible sensor materials,are discussed alongside innovations in sensor design and integration techniques that enhance performance and durability under space conditions.Through case studies of various space robotic systems,such as Mars rovers,robotic arms like Canadarm,humanoid robots like Robonaut,and specialized robots like Astrobee and LEMUR 3,this review highlights the crucial role of tactile sensing in enabling precise manipulation,environmental interaction,and autonomous operations in space.Moreover,it synthesizes current research and applications to underscore the transformative impact of tactile sensing technologies on space robotics and highlights their pivotal role in expanding human presence and scientific understanding in space,offering strategic insights and recommendations to guide future research and development in this critical field.展开更多
With the rapid development of intelligent technology,tactile sensors as sensing devices constitute the core foundation of intelligent systems.Biological organs that can sense various stimuli play vital roles in the in...With the rapid development of intelligent technology,tactile sensors as sensing devices constitute the core foundation of intelligent systems.Biological organs that can sense various stimuli play vital roles in the interaction between human beings and the external environment.Inspired by this fact,research on skin-like tactile sensors with multifunctionality and high performance has attracted extensive attention.An overview of the development of high-performance tactile sensors applied in intelligent systems is systematically presented.First,the development of tactile sensors endowed with stretchability,selfhealing,biodegradability,high resolution and self-powered capability is discussed.Then,for intelligent systems,tactile sensors with excellent application prospects in many fields,such as wearable devices,medical treatment,artificial limbs and robotics,are presented.Finally,the future prospects of tactile sensors for intelligent systems are discussed.展开更多
The absence of tactile perception limits the dexterity of a prosthetic hand and its acceptance by amputees.Recreating the sensing properties of the skin using a flexible tactile sensor could have profound implications...The absence of tactile perception limits the dexterity of a prosthetic hand and its acceptance by amputees.Recreating the sensing properties of the skin using a flexible tactile sensor could have profound implications for prosthetics,whereas existing tactile sensors often have limited functionality with cross-interference.In this study,we propose a machine-learning-assisted multifunctional tactile sensor for smart prosthetics,providing a human-like tactile sensing approach for amputations.This flexible sensor is based on a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)-melamine sponge,which enables the detection of force and temperature with low cross-coupling owing to two separate sensing mechanisms:the open-circuit voltage of the sensor as a force-insensitive intrinsic variable to measure the absolute temperature and the resistance as a temperature-insensitive extrinsic variable to measure force.Furthermore,by analyzing the unsteady heat conduction and characterizing it using real-time thermal imaging,we demonstrated that the process of open-circuit voltage variation resulting from the unsteady heat conduction is closely correlated with the heatconducting capabilities of materials,which can be utilized to discriminate between substances.Assisted by the decision tree algorithm,the device is endowed with thermal conductivity sensing ability,which allows it to identify 10 types of substances with an accuracy of 94.7%.Furthermore,an individual wearing an advanced myoelectric prosthesis equipped with the above sensor can sense pressure,temperature,and recognize different materials.We demonstrated that our multifunctional tactile sensor provides a new strategy to help amputees feel force,temperature and identify the material of objects without the aid of vision.展开更多
Tactile sensors have been used for haptic perception in intelligent robotics,smart prosthetics,and human-machine interface.The development of multifunctional tactile sensor remains a challenge and limit its applicatio...Tactile sensors have been used for haptic perception in intelligent robotics,smart prosthetics,and human-machine interface.The development of multifunctional tactile sensor remains a challenge and limit its application in flexible electronics and devices.We propose a liquid metal based tactile sensor for both temperature and force sensing which is made by 3D printing.The structural design and working principle of liquid metal based tactile sensor are firstly described.A digital light processing-based printing process is developed to print two kinds of photosensitive resins with different hardness,and used to fabricate the tactile sensor.A Wheatstone bridge circuit is designed for decoupling the temperature and forces from the measured output voltages.Characterization tests show that the tactile sensor has relatively high force sensing sensitivity of 0.29 N^(-1),and temperature sensing sensitivities are 0.55%°C−1 at 20~50°C and 0.21%°C^(−1)at 50~80°C,respectively.Then,the fabricated tactile sensor is mounted onto hand finger to measure the contact force and temperature during grasping.Results show that the 3D printed tactile sensor has excellent flexibility and durability and can accurately measure the temperature and contact forces,which demonstrate its potential in robotic manipulation applications.展开更多
基金financially supported by the Sichuan Science and Technology Program(2022YFS0025 and 2024YFFK0133)supported by the“Fundamental Research Funds for the Central Universities of China.”。
文摘Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.
基金funded by the National Natural Science Foundation of China(No.52475190 and 52275191)China Postdoctoral Science Foundation Funded Project(No.2024M751165)the Tribology Science Fund of State Key Laboratory of Tribology in Advanced Equipment(No.SKLTKF24B17).
文摘Pacinian Corpuscle(PC)is the largest tactile vibration receptor in mammalian skin,with a layered structure that enables signal amplification and high-pass filtering functions.Modern robots feature vibro-tactile sensors with excellent mechanical properties and fine resolution,but these sensors are prone to low-frequency noise interference when detecting high-frequency vibrations.In this study,a bionic PC with a longitudinally decreasing dynamic fractal structure is proposed.By creating a lumped parameter model of the PC’s layered structure,the bionic PC made of gelatin-chitosan based hydrogel can achieve high-pass filtering and specific frequency band signal amplification without requiring back-end circuits.The experimental results demonstrate that the bionic PC retains the structural characteristics of a natural PC,and the influence of structural factors,such as the number of layers in its shell,on filtration characteristics is explored.Additionally,a vibration source positioning experiment was conducted to simulate the earthquake sensing abilities of elephants.This natural structural design simplifies the filter circuit,is low-cost,cost-effective,stable in performance,and reduces redundancy in the robot’s signal circuit.Integrating this technology with robots can enhance their environmental perception,thereby improving the safety of interactions.
基金supported by National Research Foundation of Korea(2022M3D1A2054488)Technology Innovation Program(20025736,Development of MICS SoC and platform for in-vivo implantable electroceutical device)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)。
文摘Piezoelectric and triboelectric effects are of growing interest for facilitating high-sensitivity and self-powered tactile sensor applications.The working principles of piezoelectric and triboelectric nanogenerators provide strategies for enhancing output voltage signals to achieve high sensitivity.Increasing the piezoelectric constant and surface triboelectric charge density are key factors in this enhancement.Methods such as annealing processes,doping techniques,grain orientation controls,crystallinity controls,and composite structures can effectively enhance the piezoelectric constant.For increasing triboelectric output,surface plasma treatment,charge injection,microstructuring,control of dielectric constant,and structural modification are effective methods.The fabrication methods present significant opportunities in tactile sensor applications.This review article summarizes the overall piezoelectric and triboelectric fabrication processes from materials to device aspects.It highlights applications in pressure,touch,bending,texture,distance,and material recognition sensors.The conclusion section addresses challenges and research opportunities,such as limited flexibility,stretchability,decoupling from multi-stimuli,multifunctional sensors,and data processing.
基金supported by the National Key Research and Development Program of China (No.2021YFA1401103)the National Natural Science Foundation of China (Nos.61825403,61921005).
文摘Human skin,through its complex mechanoreceptor system,possesses the exceptional ability to finely perceive and dif-ferentiate multimodal mechanical stimuli,forming the biological foundation for dexterous manipulation,environmental explo-ration,and tactile perception.Tactile sensors that emulate this sensory capability,particularly in the detection,decoupling,and application of normal and shear forces,have made significant strides in recent years.This review comprehensively examines the latest research advancements in tactile sensors for normal and shear force sensing,delving into the design and decoupling methods of multi-unit structures,multilayer encapsulation structures,and bionic structures.It analyzes the advantages and disadvantages of various sensing principles,including piezoresistive,capacitive,and self-powered mechanisms,and evalu-ates their application potential in health monitoring,robotics,wearable devices,smart prosthetics,and human-machine interaction.By systematically summarizing current research progress and technical challenges,this review aims to provide forward-looking insights into future research directions,driving the development of electronic skin technology to ultimately achieve tactile perception capabilities comparable to human skin.
基金financial supports from the National Natural Science Foundation of China(No.61975173)the Key Research and Development Project of Zhejiang Province(No.2022C03103,2023C01045).
文摘As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented.
基金Supported by the National High Technology Research and Development Program of China(″863″Program)(2009AA01Z314,2009AA01Z311)the Jiangsu Province Natural Science Foundation(BK2009272)theJiangsu Province″333″Program~~
文摘Eased on the mechanism of temperature tactile sensing of human finger,a heat flux tactile sensor com- posed of a thermostat module and a heat flux sensor is designed to identify material thermal properties. The ther- mostat module maintains the sensor temperature invariable, and the heat flux sensor（Peltier device） detects the heat flux temperature difference between the thermostat module and the object surface. Two different modes of the heat flux tactile sensor are proposed, and they are simulated and experimented for different material objects. The results indicate that the heat flux tactile sensor can effectively identify different thermal properties.
基金Open access funding provided by Shanghai Jiao Tong University。
文摘Traditional triboelectric tactile sensors based on solid–solid interface have illustrated promising application prospects through optimization approach.However,the poor sensitivity and reliability caused by hard contact-electrification still poses challenges for the practical applications.In this work,a liquid–solid interface ferrofluid-based triboelectric tactile sensor(FTTS)with ultrahigh sensitivity is proposed.Relying on the fluidity and magnetism of ferrofluid,the topography of microstructure can be flexibly adjusted by directly employing ferrofluid as triboelectric material and controlling the position of outward magnet.To date,an ultrahigh sensitivity of 21.48 k Pa;for the triboelectric sensors can be achieved due to the high spike microstructure,low Young’s modulus of ferrofluid and efficient solid–liquid interface contact-electrification.The detection limit of FTTS of 1.25 Pa with a wide detection range to 390 k Pa was also obtained.In addition,the oleophobic property between ferrofluid and poly-tetra-fluoro-ethylene triboelectric layer can greatly reduce the wear and tear,resulting in the great improvement of stability.Finally,a strategy for personalized password lock with high security level has been demonstrated,illustrating a great perspective for practical application in smart home,artificial intelligence,Internet of things,etc.
基金supported by the National Natural Science Foundation of China(Nos.11372239,11321062 and 11472210)
文摘We report the first attempt to model the contacts of an ionic polymer metal composite（IPMC） based tactile sensor. The tactile sensor comprises an IPMC actuator, an IPMC sensor and the target to be detected. The system makes use of multiple contacts to work： the actuator comes into contact with the sensor and pushes the movement of sensor; the contact between the sensor and the object detects the existence and the stiffness of the target. We integrate modeling of various physical processes involved in IPMC devices to form a simulation scheme. An iteration and optimization strategy is also described to correlate the experimental and simulation results of an IPMC bending actuator to identify the two key parameters used in electromechanical transduction. Modeling the multiple contacts will aid the design and optimization of such IPMC based soft robotics.
文摘In the underwater environment, many visual sensors don’t work, and many sensors which work well for robots working in space or on land can not be used underwater. Therefore, an optical fiber slide tactile sensor was designed based on the inner modulation mechanism of optical fibers. The principles and structure of the sensor are explained in detail. Its static and dynamic characteristics were analyzed theoretically and then simulated. A dynamic characteristic model was built and the simulation made using the GA based neural network. In order to improve sensor response, the recognition model of the sensor was designed based on the ‘inverse solution’ principle of neural networks, increasing the control precision and the sensitivity of the manipulator.
文摘Because of the special underwater environment, many sensors used well in robots working in space or on the land can not be used in the underwater. So an optical fiber type slide tactile sensor is designed by the inner modulation mechanism of the intensity type optical fiber. The principle and structure of the sensor are introduced in detail. The static and dynamic characteristics are analyzed theoretically and experimentally. The dynamic characteristic model is built and the simulation is made by using genetic algorithm based on neural network. In order to use the sensor perfectly, the recognition model of the sensor is built on the basis of the principle of “inverse solution” using neural networks. The control precision and sensitivity of the manipulator are improved.
基金supported by National Natural Science Foundation of China(No.90207003)
文摘This paper reports the design and fabrication of a MEMS-based ZnO piezoelectric tactile sensor,which can be integrated on to the endoscopic grasper used in minimally invasive surgery (MIS).The sensor includes a silicon substrate, platinum bottom electrode,platinum top electrode,and a ZnO piezoelectric thin film,which is sandwiched between the two-electrode layers.The sensitivity of the micro-force sensor is analyzed in theory and the sensor exhibits high sensitivity about 7pc/uN.The application of this tactile sensor to MIS will allow the surgeon feeling the touch force between the endoscopic grasper and tissue in real-time,and manipulating the tissue safely.
基金Funded by the National Natural Science Foundation of China(No.60672024)National High Technology Research and Development Program of China (No.2007AA04Z220)
文摘In the research of 2D flexible tactile sensor matrix,pressure-sensitive conductive rubber was developed and tested in which carbon black was used as its conductive phase and silicon rubber as its matrix layer.Experiments were undertaken and the resultant data were used for its piezoresistive characteristics investigation for two kinds of electrode connection configurations,the surface directive connection and embedded connection.It is found that due to the rather strong nonlinearity of the piezoresistive characteristic curves obtained,a higher correlation relationship can be obtained by means of quadratic polynomial fitting.It also showed that the embedded electrode assembling has higher fitting accuracy while the surface directive connection has better mechanical sensitivity.
基金supported by the National Key R&D Program of China(Grant No.2019YFE0120300)the National Natural Science Foundation of China(Grant Nos.62171414,52175554,52205608,62171415,62001431)+1 种基金the Fundamental Research Program of Shanxi Province(Grant Nos.20210302123059,20210302124610)the Program for the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(Grant No.2020L0316)。
文摘Tactile sensors are one of the core components for intelligent robots to realize human-like tactile sensing functions.For the application scenarios of material classification and roughness recognition,an enhanced flexible triboelectric tactile sensor(FTTS)is proposed in this study.The FTTS is prepared based on a single-electrode triboelectric nanogenerator(SETENG),which generates the corresponding electrical signals by coming in contact with objects.To enhance the properties of the SE-TENG,the synergistic enhancement effect on the electrical output of the SE-TENG was explored by controlling the addition ratio of MXene and Carboxylated cellulose nanofibers(CNF-C).The charge-trapping mechanism of the chargetrapping layer was analyzed,and the effects of the type and thickness of the charge-trapping layer on the performance of the FTTS were systematically investigated.Inexpensive and simple fabricated braided microstructures were prepared using the template method,which showed the optimum capability in terms of self-cleaning and electrical output performance.With these improvements,the FTTS showed a voltage sensitivity of 2.88 V/10^(4)Pa in the pressure response range of 10-400 kPa,a linearity of 0.993,and a linear trend in the fitting curve.At the same time,the FTTS has a stable response frequency,fast response time,and extreme cycling stability(over 10000 cycles).In addition,in terms of roughness recognition,the FTTS can accurately recognize samples with different surface roughness.In terms of material classification,the accuracy of classifying 11materials with the visual geometry group(VGG)network reaches 96.08%.Based on these findings,FTTS-based tactile sensors offer diverse options in the future direction of electronic skin and tactile sensing.
基金supported by the National Natural Science Foundation of China(Grant 52072041)the Beijing Natural Science Foundation(Grant JQ21007)the University of Chinese Academy of Sciences(Grant Y8540XX2D2).
文摘Tactile sensors are a potential solution for material identification.However,current potential tactile sensors for material identification are pressed,expensive,and applications-confined.Here we report a clamped-on pyroelectric tactile sensor on the basis of a ferroelectric Bi_(0.5)Na_(0.5)TiO_(3) material to identify different film materials.The fabricated device exhibits different heat absorption capacities while in contact with different materials,leading to a different temperature change in the ferroelectric material under the same illumination.As a result,the device can recognize different materials by comparing the pyroelectric charge via integrating the obtained current under the same irradiation of 365nmlight-emitting diode.The clamped-on pyroelectric tactile sensor can identify six individual materials with a high accuracy of 98.8%and a fast response of 40 ms.All of the above processes can be accomplished with an intelligent material identification system.The device provides a new solution for material identification and lays a foundation for smart factories and laboratories.
基金National Natural Science Foundation of China,Grant/Award Number:62174068Rizhao City Key Research and Development Program,Grant/Award Number:2021ZDYF010102+1 种基金Qilu Young Scholar Program of Shandong UniversityNational Research Foundation of Korea(NRF)grant funded by the Korea government(MIST),Grant/Award Number:RS-2023-00302751。
文摘Intelligent applications,with tactile sensors at their core,represent significant advancement in the field of artificial intelligence.However,achieving perception abilities in tactile sensors that match or exceed human skin remains a formidable challenge.Consequently,the design and implementation of hierarchical structural materials are considered the optimal solution to this challenge.In contrast to conventional methods,such as complicated lithography and three-dimensional printing,the cost-effective and scalable nature of advanced solution-synthesis methods makes them ideal for preparing diverse tactile sensors with hierarchical structural materials.However,the process and applicability of advanced solution synthesis methods have yet to form a seamless system.Accordingly,the development and intellectualization of tactile sensors based on advanced solution synthesis methods are still in their early stages,and require a comprehensive and systematic review to usher in progress.This study delves into the advantages and disadvantages of various advanced solution synthesis methods,providing detailed insights.Furthermore,the positive effects of hierarchical structural materials constructed using these methods in tactile sensors and their intelligent applications are also discussed in depth.Finally,the challenges and future opportunities faced by this emerging field are summarized.
基金supported by the National Natural Science Foundation of China(No.51777215)the Special Foundation of the Taishan Scholar Project(No.tsqn202211077)+1 种基金the Shandong Provincial Natural Science Foundation(No.ZR2023ME118)the Natural Science Foundation of Qingdao City(No.23-2-1-219-zyyd-jch).
文摘In recent years,multi-modal flexible tactile sensors have become an important direction in the development of electronic skin because of their excellent sensitivity,flexibility and wearable properties.In this work,a humidity-pressure multi-modal flexible sensor based on polypyrrole(PPy)/Ti_(3)C_(2)T_(x) sensitive film packaged with porous polydimethylsiloxane(PDMS)is investigated by combining the sensitive structure generation mechanism of in situ polymerization to achieve the simultaneous detection of humidity and pressure,which has a sensitivity of 89,113.4Ω/%RH in a large humidity range of 0%-97%RH,and response/recovery time of 2.5/1.9 s.The tactile pressure sensing has a high sensitivity,a fast response of 67/52 ms,and a wide detection limit.The device also has excellent performance in terms of stability and repeatability,making it promising for respiratory pattern and motion detection.This work provides a new solution to address the construction of multi-modal tactile sensors with potential applications in the fields of medical health,epidemic prevention.
基金supported by FAST(19FAYORA14)of the Canadian Space Agency,Discovery Grant(RGPIN2024-06290)supported by CREATE grant(555425-2021)&Discovery grant(RGPIN-2024-06290)of the Natural Sciences and Engineering Research Council of Canada.
文摘This review explores the current state and future prospects of tactile sensing technologies in space robotics,addressing the unique challenges posed by harsh space environments such as extreme temperatures,radiation,microgravity,and vacuum conditions,which necessitate specialized sensor designs.We provide a detailed analysis of four primary types of tactile sensors:resistive,capacitive,piezoelectric,and optical,evaluating their operating principles,advantages,limitations,and specific applications in space exploration.Recent advancements in materials science,including the development of radiation-hardened components and flexible sensor materials,are discussed alongside innovations in sensor design and integration techniques that enhance performance and durability under space conditions.Through case studies of various space robotic systems,such as Mars rovers,robotic arms like Canadarm,humanoid robots like Robonaut,and specialized robots like Astrobee and LEMUR 3,this review highlights the crucial role of tactile sensing in enabling precise manipulation,environmental interaction,and autonomous operations in space.Moreover,it synthesizes current research and applications to underscore the transformative impact of tactile sensing technologies on space robotics and highlights their pivotal role in expanding human presence and scientific understanding in space,offering strategic insights and recommendations to guide future research and development in this critical field.
基金supported by the National Key Research and Development Program of China (2016YFA0202703)the National Natural Science Foundation of China (51622205, 61675027, 51432005, 61505010, and 51502018)+1 种基金Beijing City Committee of Science and Technology (Z171100002017019 and Z181100004418004)Beijing Natural Science Foundation (4181004, 4182080, 4184110, and 2184131)
文摘With the rapid development of intelligent technology,tactile sensors as sensing devices constitute the core foundation of intelligent systems.Biological organs that can sense various stimuli play vital roles in the interaction between human beings and the external environment.Inspired by this fact,research on skin-like tactile sensors with multifunctionality and high performance has attracted extensive attention.An overview of the development of high-performance tactile sensors applied in intelligent systems is systematically presented.First,the development of tactile sensors endowed with stretchability,selfhealing,biodegradability,high resolution and self-powered capability is discussed.Then,for intelligent systems,tactile sensors with excellent application prospects in many fields,such as wearable devices,medical treatment,artificial limbs and robotics,are presented.Finally,the future prospects of tactile sensors for intelligent systems are discussed.
基金the funding support from the National Key R&D Program of China(2020YFB2008501)the National Science Fund for Distinguished Young Scholars of China(62125112)+4 种基金the National Natural Science Foundation of China(62071462,62071463)the Youth Promotion Association of Chinese Academy of Sciences(2020320)the Jiangxi Provincial Natural Science Foundation(20224ACB212001)the Foundation Research Project of Jiangsu Province(BK20201195)the Suzhou Key Industrial Technology Innovation Project(SYG202029).
文摘The absence of tactile perception limits the dexterity of a prosthetic hand and its acceptance by amputees.Recreating the sensing properties of the skin using a flexible tactile sensor could have profound implications for prosthetics,whereas existing tactile sensors often have limited functionality with cross-interference.In this study,we propose a machine-learning-assisted multifunctional tactile sensor for smart prosthetics,providing a human-like tactile sensing approach for amputations.This flexible sensor is based on a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)-melamine sponge,which enables the detection of force and temperature with low cross-coupling owing to two separate sensing mechanisms:the open-circuit voltage of the sensor as a force-insensitive intrinsic variable to measure the absolute temperature and the resistance as a temperature-insensitive extrinsic variable to measure force.Furthermore,by analyzing the unsteady heat conduction and characterizing it using real-time thermal imaging,we demonstrated that the process of open-circuit voltage variation resulting from the unsteady heat conduction is closely correlated with the heatconducting capabilities of materials,which can be utilized to discriminate between substances.Assisted by the decision tree algorithm,the device is endowed with thermal conductivity sensing ability,which allows it to identify 10 types of substances with an accuracy of 94.7%.Furthermore,an individual wearing an advanced myoelectric prosthesis equipped with the above sensor can sense pressure,temperature,and recognize different materials.We demonstrated that our multifunctional tactile sensor provides a new strategy to help amputees feel force,temperature and identify the material of objects without the aid of vision.
基金This work was supported by National Nature Science Foundation of China[51575485]the Natural Science Foundation of Zhejiang Province for Distinguished Young Scientists[LR19E050001]Open Fund Project of Zhejiang Laboratory[2019MC0AB02].
文摘Tactile sensors have been used for haptic perception in intelligent robotics,smart prosthetics,and human-machine interface.The development of multifunctional tactile sensor remains a challenge and limit its application in flexible electronics and devices.We propose a liquid metal based tactile sensor for both temperature and force sensing which is made by 3D printing.The structural design and working principle of liquid metal based tactile sensor are firstly described.A digital light processing-based printing process is developed to print two kinds of photosensitive resins with different hardness,and used to fabricate the tactile sensor.A Wheatstone bridge circuit is designed for decoupling the temperature and forces from the measured output voltages.Characterization tests show that the tactile sensor has relatively high force sensing sensitivity of 0.29 N^(-1),and temperature sensing sensitivities are 0.55%°C−1 at 20~50°C and 0.21%°C^(−1)at 50~80°C,respectively.Then,the fabricated tactile sensor is mounted onto hand finger to measure the contact force and temperature during grasping.Results show that the 3D printed tactile sensor has excellent flexibility and durability and can accurately measure the temperature and contact forces,which demonstrate its potential in robotic manipulation applications.
