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
This letter provides a concise review of the pertinent literature on visual and tactile hallucinations in elderly patients.The discussion addresses differential diagnoses and potential underlying mechanisms,as well as...This letter provides a concise review of the pertinent literature on visual and tactile hallucinations in elderly patients.The discussion addresses differential diagnoses and potential underlying mechanisms,as well as the psychopathology associated with tactile hallucinations,and emphasizes the necessity for invest-igation into the possibility of coexisting delusional infestation(parasitosis).These symptoms frequently manifest in patients with primary psychotic disorders,organic mental disorders,and substance use disorders.The proposed pathophy-siological mechanisms may involve dopaminergic imbalances and dysfunction of the striatal dopamine transporter.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
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
It is significant to process textures with special functions similar to animal surfaces based on bionics and improve the friction stability and contact comfort of contact surfaces for the surface texture design of tac...It is significant to process textures with special functions similar to animal surfaces based on bionics and improve the friction stability and contact comfort of contact surfaces for the surface texture design of tactile products.In this paper,a bionic hexagonal micro-convex texture was prepared on an acrylic surface by laser processing.The friction mechanism of a finger touching the bionic hexagonal micro-convex texture under different touch speeds and pressures,and the effect of the height of the texture on tactile perception were investigated by finite element,subjective evaluation,friction,and EEG tests.The results showed that the deformation friction was the main friction component when the finger touched the bionic hexagonal texture,and the slipperiness and friction factor showed a significant negative correlation.As the touch speed decreased or the touch force increased,the hysteresis friction of the fingers as well as the interlocking friction increased,and the slipperiness perception decreased.The bionic hexagonal texture with higher convexity caused a higher friction factor,lower slipperiness perception,and lower P300 peak.Hexagonal textures with lower convexity,lower friction factor,and higher slipperiness perception required greater brain attentional resources and intensity of tactile information processing during tactile perception.展开更多
Ionogels have demonstrated substantial applications in smart wearable systems,soft robotics,and biomedical engineering due to the exceptional ionic conductivity and optical transparency.However,achieving ionogels with...Ionogels have demonstrated substantial applications in smart wearable systems,soft robotics,and biomedical engineering due to the exceptional ionic conductivity and optical transparency.However,achieving ionogels with desirable mechanical properties,environmental stability,and multi-mode sensing remains challenging.Here,we propose a simple strategy for the fabrication of multifunctional silk fabric-based ionogels(BSFIGs).The resulting fabric ionogels exhibits superior mechanical properties,with high tensile strength(11.3 MPa)and work of fracture(2.53 MJ/m^(3)).And its work of fracture still has 1.42 MJ/m^(3)as the notch increased to 50%,indicating its crack growth insensitivity.These ionogels can be used as sensors for strain,temperature,and tactile multimode sensing,demonstrating a gauge factor of 1.19 and a temperature coefficient of resistance of3.17/℃^(-1).Furthermore,these ionogels can be used for the detection of different roughness and as touch screens.The ionogels also exhibit exceptional optical transmittance and environmental stability even at80℃.Our scalable fabrication process broadens the application potential of these multifunctional ionogels in diverse fields,from smart systems to extreme environments.展开更多
The Tactile Internet of Things(TIoT)promises transformative applications—ranging from remote surgery to industrial robotics—by incorporating haptic feedback into traditional IoT systems.Yet TIoT’s stringent require...The Tactile Internet of Things(TIoT)promises transformative applications—ranging from remote surgery to industrial robotics—by incorporating haptic feedback into traditional IoT systems.Yet TIoT’s stringent requirements for ultra-low latency,high reliability,and robust privacy present significant challenges.Conventional centralized Federated Learning(FL)architectures struggle with latency and privacy constraints,while fully distributed FL(DFL)faces scalability and non-IID data issues as client populations expand and datasets become increasingly heterogeneous.To address these limitations,we propose a Clustered Distributed Federated Learning(CDFL)architecture tailored for a 6G-enabled TIoT environment.Clients are grouped into clusters based on data similarity and/or geographical proximity,enabling local intra-cluster aggregation before inter-cluster model sharing.This hierarchical,peer-to-peer approach reduces communication overhead,mitigates non-IID effects,and eliminates single points of failure.By offloading aggregation to the network edge and leveraging dynamic clustering,CDFL enhances both computational and communication efficiency.Extensive analysis and simulation demonstrate that CDFL outperforms both centralized FL and DFL as the number of clients grows.Specifically,CDFL demonstrates up to a 30%reduction in training time under highly heterogeneous data distributions,indicating faster convergence.It also reduces communication overhead by approximately 40%compared to DFL.These improvements and enhanced network performance metrics highlight CDFL’s effectiveness for practical TIoT deployments.These results validate CDFL as a scalable,privacy-preserving solution for next-generation TIoT applications.展开更多
High-fidelity tactile rendering offers significant potential for improving the richness and immersion of touchscreen interactions.This study focuses on a quantitative description of tactile rendering fidelity using a ...High-fidelity tactile rendering offers significant potential for improving the richness and immersion of touchscreen interactions.This study focuses on a quantitative description of tactile rendering fidelity using a custom-designed hybrid electrovibration and mechanical vibration(HEM)device.An electrovibration and mechanical vibration(EMV)algorithm that renders 3D gratings with different physical heights was proposed and shown to achieve 81%accuracy in shape recognition.Models of tactile rendering fidelity were established based on the evaluation of the height discrimination threshold,and the psychophysical-physical relationships between the discrimination and reference heights were well described by a modification of Weber’s law,with correlation coefficients higher than 0.9.The physiological-physical relationship between the pulse firing rate and the physical stimulation voltage was modeled using the Izhikevich spiking model with a logarithmic relationship.展开更多
With the rapid development of flexible electronics,the tactile systems for object recognition are becoming increasingly delicate.This paper presents the design of a tactile glove for object recognition,integrating 243...With the rapid development of flexible electronics,the tactile systems for object recognition are becoming increasingly delicate.This paper presents the design of a tactile glove for object recognition,integrating 243 palm pressure units and 126 finger joint strain units that are implemented by piezoresistive Velostat film.The palm pressure and joint bending strain data from the glove were collected using a two-dimensional resistance array scanning circuit and further converted into tactile images with a resolution of 32×32.To verify the effect of tactile data types on recognition precision,three datasets of tactile images were respectively built by palm pressure data,joint bending strain data,and a tactile data combing of both palm pressure and joint bending strain.An improved residual convolutional neural network(CNN)model,SP-ResNet,was developed by light-weighting ResNet-18 to classify these tactile images.Experimental results show that the data collection method combining palm pressure and joint bending strain demonstrates a 4.33%improvement in recognition precision compared to the best results obtained by using only palm pressure or joint bending strain.The recognition precision of 95.50%for 16 objects can be achieved by the presented tactile glove with SP-ResNet of less computation cost.The presented tactile system can serve as a sensing platform for intelligent prosthetics and robot grippers.展开更多
Humans can perceive our complex world through multi-sensory fusion.Under limited visual conditions,people can sense a variety of tactile signals to identify objects accurately and rapidly.However,replicating this uniq...Humans can perceive our complex world through multi-sensory fusion.Under limited visual conditions,people can sense a variety of tactile signals to identify objects accurately and rapidly.However,replicating this unique capability in robots remains a significant challenge.Here,we present a new form of ultralight multifunctional tactile nano-layered carbon aerogel sensor that provides pressure,temperature,material recognition and 3D location capabilities,which is combined with multimodal supervised learning algorithms for object recognition.The sensor exhibits human-like pressure(0.04–100 kPa)and temperature(21.5–66.2℃)detection,millisecond response times(11 ms),a pressure sensitivity of 92.22 kPa^(−1)and triboelectric durability of over 6000 cycles.The devised algorithm has universality and can accommodate a range of application scenarios.The tactile system can identify common foods in a kitchen scene with 94.63%accuracy and explore the topographic and geomorphic features of a Mars scene with 100%accuracy.This sensing approach empowers robots with versatile tactile perception to advance future society toward heightened sensing,recognition and intelligence.展开更多
Background: Premature cervical softening and shortening may be considered an early mechanical failure that predispose to preterm birth. Purpose: This study aims to explore the applicability of an innovative cervical t...Background: Premature cervical softening and shortening may be considered an early mechanical failure that predispose to preterm birth. Purpose: This study aims to explore the applicability of an innovative cervical tactile ultrasound approach for predicting spontaneous preterm birth (sPTB). Materials and Methods: Eligible participants were women with low-risk singleton pregnancies in their second trimester, enrolled in this prospective observational study. A Cervix Monitor (CM) device was designed with a vaginal probe comprising four tactile sensors and a single ultrasound transducer operating at 5 MHz. The probe enabled the application of controllable pressure to the external cervical surface, facilitating the acquisition of stress-strain data from both anterior and posterior cervical sectors. Gestational age at delivery was recorded and compared against cervical elasticity. Results: CM examination data were analyzed for 127 women at 24<sup>0/7</sup> - 28<sup>6/7</sup> gestational weeks. sPTB was observed in 6.3% of the cases. The preterm group exhibited a lower average cervical stress-to-strain ratio (elasticity) of 0.70 ± 0.26 kPa/mm compared to the term group’s 1.63 ± 0.65 kPa/mm with a p-value of 1.1 × 10<sup>−</sup><sup>4</sup>. Diagnostic accuracy for predicting spontaneous preterm birth based solely on cervical elasticity data was found to be 95.0% (95% CI, 88.5 - 100.0). Conclusion: These findings suggest that measuring cervical elasticity with the designed tactile ultrasound probe has the potential to predict spontaneous preterm birth in a cost-effective manner.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
Tactile paving is a professional road facility to ensure the safe travel of people with visual impairment.However,there are many problems with tactile paving travel in practice.For one,some tactile paving is seriously...Tactile paving is a professional road facility to ensure the safe travel of people with visual impairment.However,there are many problems with tactile paving travel in practice.For one,some tactile paving is seriously damaged,and the other is the accumulation of obstacles.How to help visually impaired people recognize and locate obstacles in tactile paving is a problem worth studying.In this paper,image recognition technology is used to recognize the tactile paving pictures with obstacles,and an attention mechanism is used to optimize samples to improve recognition accuracy.展开更多
We investigated the long-lasting effects of early postnatal tactile stimulation （TS） and maternal separation （MS） on the emotional behaviors of adult female rats. A split-litter design was introduced to remove con...We investigated the long-lasting effects of early postnatal tactile stimulation （TS） and maternal separation （MS） on the emotional behaviors of adult female rats. A split-litter design was introduced to remove confusing factors such as maternal disturbance. Pups of the non-tactile stimulation （NTS） group did not receive any handling. Pups subjected to the TS treatment were handled and marked for approximately 30 s daily from postnatal days （PND） 2 - 9 or from PND 10 - 17. Pups subjected to the MS treatment were handled and marked in the same way as the TS pups and then individually placed in a cup with familiar nest bedding for 1 h daily. At the age of 3 months, female rats with different neonatal experiences were employed in the light/dark box test and the one-trial passive avoidance response. Both PND 2 - 9 TS and PND 10 - 17 TS groups exhibited more time spent in the illuminated chamber of the light/dark box, and longer step-through latencies in the passive avoidance response when compared to the NTS group, indicating that early life TS treatment reduced novelty-induced anxious emotion and facilitated the retention of emotional memory in adult female rats. No significant effects were found on any behavioral measures between the MS groups and the TS groups, suggesting that neonatal short-time MS treatment was not intensive enough to alter the emotional behaviors, at least in female rats. Infantile age was not an effective factor for these measures. This result supports the hypothesis that neonatal tactile stimulation and maternal separation lead to different effects on the neural development of postnatal pups.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
From the perspective of the tactile comfort of underwear fabrics, 179 kinds of underwear fabrics were selected to test tactile related performance indices using the fabric touch tester(FTT), and the relationship betwe...From the perspective of the tactile comfort of underwear fabrics, 179 kinds of underwear fabrics were selected to test tactile related performance indices using the fabric touch tester(FTT), and the relationship between physical indicators and tactile sensation of different fiber types of underwear fabrics was studied to establish a digital regression model by a stepwise regression method. The experimental results show that fabric fiber composition, compression characteristics, surface friction coefficient, surface roughness amplitude, bending characteristics, and maximum thermal conductivity significantly affect the level of tactile comfort of underwear fabrics, the composition of underwear fabrics has a significant effect on soft touch, and the clustering method and the grading method can effectively rate the level of tactile comfort of underwear fabrics.展开更多
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
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.
文摘This letter provides a concise review of the pertinent literature on visual and tactile hallucinations in elderly patients.The discussion addresses differential diagnoses and potential underlying mechanisms,as well as the psychopathology associated with tactile hallucinations,and emphasizes the necessity for invest-igation into the possibility of coexisting delusional infestation(parasitosis).These symptoms frequently manifest in patients with primary psychotic disorders,organic mental disorders,and substance use disorders.The proposed pathophy-siological mechanisms may involve dopaminergic imbalances and dysfunction of the striatal dopamine transporter.
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 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the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.48)。
文摘It is significant to process textures with special functions similar to animal surfaces based on bionics and improve the friction stability and contact comfort of contact surfaces for the surface texture design of tactile products.In this paper,a bionic hexagonal micro-convex texture was prepared on an acrylic surface by laser processing.The friction mechanism of a finger touching the bionic hexagonal micro-convex texture under different touch speeds and pressures,and the effect of the height of the texture on tactile perception were investigated by finite element,subjective evaluation,friction,and EEG tests.The results showed that the deformation friction was the main friction component when the finger touched the bionic hexagonal texture,and the slipperiness and friction factor showed a significant negative correlation.As the touch speed decreased or the touch force increased,the hysteresis friction of the fingers as well as the interlocking friction increased,and the slipperiness perception decreased.The bionic hexagonal texture with higher convexity caused a higher friction factor,lower slipperiness perception,and lower P300 peak.Hexagonal textures with lower convexity,lower friction factor,and higher slipperiness perception required greater brain attentional resources and intensity of tactile information processing during tactile perception.
基金supported by the National Natural Science Foundation of China(No.12302192)the Fundamental Research Funds for the Central Universities(No.SWU-KQ22025)+4 种基金the Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJQN202300222)Natural Science Foundation of Chongqing(No.cstc2021jcyj-msxmX0241)the Fund for Innovative Research Groups of Natural Science Foundation of Hebei Province(No.A2024202045)Key Technologies and Demonstration Application Research Project for Large-scale Lithium-ion Hybrid Energy Storage Equipment(No.HC23118)Major Basic Research Project of Hebei Province Natural Science Foundation(No.A2023202049).
文摘Ionogels have demonstrated substantial applications in smart wearable systems,soft robotics,and biomedical engineering due to the exceptional ionic conductivity and optical transparency.However,achieving ionogels with desirable mechanical properties,environmental stability,and multi-mode sensing remains challenging.Here,we propose a simple strategy for the fabrication of multifunctional silk fabric-based ionogels(BSFIGs).The resulting fabric ionogels exhibits superior mechanical properties,with high tensile strength(11.3 MPa)and work of fracture(2.53 MJ/m^(3)).And its work of fracture still has 1.42 MJ/m^(3)as the notch increased to 50%,indicating its crack growth insensitivity.These ionogels can be used as sensors for strain,temperature,and tactile multimode sensing,demonstrating a gauge factor of 1.19 and a temperature coefficient of resistance of3.17/℃^(-1).Furthermore,these ionogels can be used for the detection of different roughness and as touch screens.The ionogels also exhibit exceptional optical transmittance and environmental stability even at80℃.Our scalable fabrication process broadens the application potential of these multifunctional ionogels in diverse fields,from smart systems to extreme environments.
基金supported by the Deanship of Scientific Research(DSR),King Abdulaziz University,Jeddah,under grant No.GPIP:2040-611-2024。
文摘The Tactile Internet of Things(TIoT)promises transformative applications—ranging from remote surgery to industrial robotics—by incorporating haptic feedback into traditional IoT systems.Yet TIoT’s stringent requirements for ultra-low latency,high reliability,and robust privacy present significant challenges.Conventional centralized Federated Learning(FL)architectures struggle with latency and privacy constraints,while fully distributed FL(DFL)faces scalability and non-IID data issues as client populations expand and datasets become increasingly heterogeneous.To address these limitations,we propose a Clustered Distributed Federated Learning(CDFL)architecture tailored for a 6G-enabled TIoT environment.Clients are grouped into clusters based on data similarity and/or geographical proximity,enabling local intra-cluster aggregation before inter-cluster model sharing.This hierarchical,peer-to-peer approach reduces communication overhead,mitigates non-IID effects,and eliminates single points of failure.By offloading aggregation to the network edge and leveraging dynamic clustering,CDFL enhances both computational and communication efficiency.Extensive analysis and simulation demonstrate that CDFL outperforms both centralized FL and DFL as the number of clients grows.Specifically,CDFL demonstrates up to a 30%reduction in training time under highly heterogeneous data distributions,indicating faster convergence.It also reduces communication overhead by approximately 40%compared to DFL.These improvements and enhanced network performance metrics highlight CDFL’s effectiveness for practical TIoT deployments.These results validate CDFL as a scalable,privacy-preserving solution for next-generation TIoT applications.
基金Supported by the National Natural Science Foundation of China under Grants 61631010 and 61806085.
文摘High-fidelity tactile rendering offers significant potential for improving the richness and immersion of touchscreen interactions.This study focuses on a quantitative description of tactile rendering fidelity using a custom-designed hybrid electrovibration and mechanical vibration(HEM)device.An electrovibration and mechanical vibration(EMV)algorithm that renders 3D gratings with different physical heights was proposed and shown to achieve 81%accuracy in shape recognition.Models of tactile rendering fidelity were established based on the evaluation of the height discrimination threshold,and the psychophysical-physical relationships between the discrimination and reference heights were well described by a modification of Weber’s law,with correlation coefficients higher than 0.9.The physiological-physical relationship between the pulse firing rate and the physical stimulation voltage was modeled using the Izhikevich spiking model with a logarithmic relationship.
基金supported by the Key Research and Development Program of Shaanxi Province(No.2024 GX-YBXM-178)the Shaanxi Province Qinchuangyuan“Scientists+Engineers”Team Development(No.2022KXJ032)。
文摘With the rapid development of flexible electronics,the tactile systems for object recognition are becoming increasingly delicate.This paper presents the design of a tactile glove for object recognition,integrating 243 palm pressure units and 126 finger joint strain units that are implemented by piezoresistive Velostat film.The palm pressure and joint bending strain data from the glove were collected using a two-dimensional resistance array scanning circuit and further converted into tactile images with a resolution of 32×32.To verify the effect of tactile data types on recognition precision,three datasets of tactile images were respectively built by palm pressure data,joint bending strain data,and a tactile data combing of both palm pressure and joint bending strain.An improved residual convolutional neural network(CNN)model,SP-ResNet,was developed by light-weighting ResNet-18 to classify these tactile images.Experimental results show that the data collection method combining palm pressure and joint bending strain demonstrates a 4.33%improvement in recognition precision compared to the best results obtained by using only palm pressure or joint bending strain.The recognition precision of 95.50%for 16 objects can be achieved by the presented tactile glove with SP-ResNet of less computation cost.The presented tactile system can serve as a sensing platform for intelligent prosthetics and robot grippers.
基金the National Natural Science Foundation of China(Grant No.52072041)the Beijing Natural Science Foundation(Grant No.JQ21007)+2 种基金the University of Chinese Academy of Sciences(Grant No.Y8540XX2D2)the Robotics Rhino-Bird Focused Research Project(No.2020-01-002)the Tencent Robotics X Laboratory.
文摘Humans can perceive our complex world through multi-sensory fusion.Under limited visual conditions,people can sense a variety of tactile signals to identify objects accurately and rapidly.However,replicating this unique capability in robots remains a significant challenge.Here,we present a new form of ultralight multifunctional tactile nano-layered carbon aerogel sensor that provides pressure,temperature,material recognition and 3D location capabilities,which is combined with multimodal supervised learning algorithms for object recognition.The sensor exhibits human-like pressure(0.04–100 kPa)and temperature(21.5–66.2℃)detection,millisecond response times(11 ms),a pressure sensitivity of 92.22 kPa^(−1)and triboelectric durability of over 6000 cycles.The devised algorithm has universality and can accommodate a range of application scenarios.The tactile system can identify common foods in a kitchen scene with 94.63%accuracy and explore the topographic and geomorphic features of a Mars scene with 100%accuracy.This sensing approach empowers robots with versatile tactile perception to advance future society toward heightened sensing,recognition and intelligence.
文摘Background: Premature cervical softening and shortening may be considered an early mechanical failure that predispose to preterm birth. Purpose: This study aims to explore the applicability of an innovative cervical tactile ultrasound approach for predicting spontaneous preterm birth (sPTB). Materials and Methods: Eligible participants were women with low-risk singleton pregnancies in their second trimester, enrolled in this prospective observational study. A Cervix Monitor (CM) device was designed with a vaginal probe comprising four tactile sensors and a single ultrasound transducer operating at 5 MHz. The probe enabled the application of controllable pressure to the external cervical surface, facilitating the acquisition of stress-strain data from both anterior and posterior cervical sectors. Gestational age at delivery was recorded and compared against cervical elasticity. Results: CM examination data were analyzed for 127 women at 24<sup>0/7</sup> - 28<sup>6/7</sup> gestational weeks. sPTB was observed in 6.3% of the cases. The preterm group exhibited a lower average cervical stress-to-strain ratio (elasticity) of 0.70 ± 0.26 kPa/mm compared to the term group’s 1.63 ± 0.65 kPa/mm with a p-value of 1.1 × 10<sup>−</sup><sup>4</sup>. Diagnostic accuracy for predicting spontaneous preterm birth based solely on cervical elasticity data was found to be 95.0% (95% CI, 88.5 - 100.0). Conclusion: These findings suggest that measuring cervical elasticity with the designed tactile ultrasound probe has the potential to predict spontaneous preterm birth in a cost-effective manner.
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 Jiangsu Province College Student Innovation Training Program(Project No.20221127684Y)the Talent Startup project of Nanjing Institute of Technology(Project No.YKJ202117)。
文摘Tactile paving is a professional road facility to ensure the safe travel of people with visual impairment.However,there are many problems with tactile paving travel in practice.For one,some tactile paving is seriously damaged,and the other is the accumulation of obstacles.How to help visually impaired people recognize and locate obstacles in tactile paving is a problem worth studying.In this paper,image recognition technology is used to recognize the tactile paving pictures with obstacles,and an attention mechanism is used to optimize samples to improve recognition accuracy.
文摘We investigated the long-lasting effects of early postnatal tactile stimulation （TS） and maternal separation （MS） on the emotional behaviors of adult female rats. A split-litter design was introduced to remove confusing factors such as maternal disturbance. Pups of the non-tactile stimulation （NTS） group did not receive any handling. Pups subjected to the TS treatment were handled and marked for approximately 30 s daily from postnatal days （PND） 2 - 9 or from PND 10 - 17. Pups subjected to the MS treatment were handled and marked in the same way as the TS pups and then individually placed in a cup with familiar nest bedding for 1 h daily. At the age of 3 months, female rats with different neonatal experiences were employed in the light/dark box test and the one-trial passive avoidance response. Both PND 2 - 9 TS and PND 10 - 17 TS groups exhibited more time spent in the illuminated chamber of the light/dark box, and longer step-through latencies in the passive avoidance response when compared to the NTS group, indicating that early life TS treatment reduced novelty-induced anxious emotion and facilitated the retention of emotional memory in adult female rats. No significant effects were found on any behavioral measures between the MS groups and the TS groups, suggesting that neonatal short-time MS treatment was not intensive enough to alter the emotional behaviors, at least in female rats. Infantile age was not an effective factor for these measures. This result supports the hypothesis that neonatal tactile stimulation and maternal separation lead to different effects on the neural development of postnatal pups.
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2021 Graduate Research Innovation Project of BIFT,China (No.X2021-020)。
文摘From the perspective of the tactile comfort of underwear fabrics, 179 kinds of underwear fabrics were selected to test tactile related performance indices using the fabric touch tester(FTT), and the relationship between physical indicators and tactile sensation of different fiber types of underwear fabrics was studied to establish a digital regression model by a stepwise regression method. The experimental results show that fabric fiber composition, compression characteristics, surface friction coefficient, surface roughness amplitude, bending characteristics, and maximum thermal conductivity significantly affect the level of tactile comfort of underwear fabrics, the composition of underwear fabrics has a significant effect on soft touch, and the clustering method and the grading method can effectively rate the level of tactile comfort of underwear fabrics.
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.
