In the era of Metaverse and virtual reality(VR)/augmented reality(AR),capturing finger motion and force interactions is crucial for immersive human-machine interfaces.This study introduces a flexible electronic skin f...In the era of Metaverse and virtual reality(VR)/augmented reality(AR),capturing finger motion and force interactions is crucial for immersive human-machine interfaces.This study introduces a flexible electronic skin for the index finger,addressing coupled perception of both state and process in dynamic tactile sensing.The device integrates resistive and giant magnetoelastic sensors,enabling detection of surface pressure and finger joint bending.This e-skin identifies three phases of finger action:bending state,dynamic normal force and tangential force(sweeping).The system comprises resistive carbon nanotubes(CNT)/polydimethylsiloxane(PDMS)films for bending sensing and magnetoelastic sensors(NdFeB particles,EcoFlex,and flexible coils)for pressure detection.The inward bending resistive sensor,based on self-assembled microstructures,exhibits directional specificity with a response time under 120 ms and bending sensitivity from 0°to 120°.The magnetoelastic sensors demonstrate specific responses to frequency and deformation magnitude,as well as sensitivity to surface roughness during sliding and material hardness.The system’s capability is demonstrated through tactile-based bread type and condition recognition,achieving 92%accuracy.This intelligent patch shows broad potential in enhancing interactions across various fields,from VR/AR interfaces and medical diagnostics to smart manufacturing and industrial automation.展开更多
In clinical work,many soft medical pipelines are located deep within the body,resulting in a lack of feedback regarding bending or folding conditions,which presents significant challenges for medical staff.To solve th...In clinical work,many soft medical pipelines are located deep within the body,resulting in a lack of feedback regarding bending or folding conditions,which presents significant challenges for medical staff.To solve the problem,this study innovatively designs a flexible bending sensor,which can be attached to the medical pipelines and monitor the bending conditions.Based on a flexible substrate with secondary microstructures copied from champagne rose petals,the interdigital electrodes are designed to enhance the sensitivity of the sensor due to the amplifying effect.A high sensitivity of 2.209%?1in a bending strain range of 8.9%,and a stable repeatability for over 6000 cycles under 1.8%bending strain are achieved by the sensor.By integrating the bending sensor,here,the nasogastric tube,femoral vein catheter,and tracheal intubation are used to demonstrate the sensing performance.Additionally,during the measurement,the sensing signals are processed and transformed to the bending angles simultaneously,enabling the direct visualization of the bending conditions of the pipelines.This work proposes innovative applications for bending sensors in medical technology and establishes a foundation for further research on flexible bending sensors.展开更多
A fiber cladding surface plasmon resonance(SPR)bending sensor is realized by the cladding of the fiber structure.By employing coating film,the sensing zone is protected and the toughness of the sensor increases.Three ...A fiber cladding surface plasmon resonance(SPR)bending sensor is realized by the cladding of the fiber structure.By employing coating film,the sensing zone is protected and the toughness of the sensor increases.Three different sensing probes are tested,the experiment results indicate that the two parameters(wavelength sensitivity and light intensity sensitivity)sensing performances of the eccentric butt joint structures are superior to that of hetero-core structure,and the SPR bending sensor based on hetero-core structure is stable and uneasy to damage.By employing hetero-core fiber and silver film,a fiber cladding SPR bending sensor with better stabilization and sensing performance is realized.The proposed fabricating method of sensing probe with coating film provides a new approach for fiber SPR-distributed bending sensor.展开更多
An exceptional-point(EP)enhanced fiber-optic bending sensor is reported.The sensor is implemented based on paritytime(PT)-symmetry using two coupled Fabry-Perot(FP)resonators consisting of three cascaded fiber Bragg g...An exceptional-point(EP)enhanced fiber-optic bending sensor is reported.The sensor is implemented based on paritytime(PT)-symmetry using two coupled Fabry-Perot(FP)resonators consisting of three cascaded fiber Bragg gratings(FBGs)inscribed in an erbium-ytterbium co-doped fiber(EYDF).The EP is achieved by controlling the pumping power to manipulate the gain and loss of the gain and loss FP resonators.Once a bending force is applied to the gain FP resonator to make the operation of the system away from its EP,frequency splitting occurs,and the frequency spacing is a nonlinear function of the bending curvature,with an increased slope near the EP.Thus,by measuring the frequency spacing,the bending information is measured with increased sensitivity.To achieve high-speed and high-resolution interrogation,the optical spectral response of the sensor is converted to the microwave domain by implementing a dual-passband microwave-photonic filter(MPF),with the spacing between the two passbands equal to that of the frequency splitting.The proposed sensor is evaluated experimentally.A curvature sensing range from 0.28 to 2.74 m^(−1) is achieved with an accuracy of 7.56×10^(−4 )m^(−1 )and a sensitivity of 1.32 GHz/m^(−1),which is more than 4 times higher than those reported previously.展开更多
Soft bending sensors offer high sensitivity and a large deformation range,making them ideal for robotics and healthcare.However,existing sensors made from organic materials often fail under large tensile stresses and ...Soft bending sensors offer high sensitivity and a large deformation range,making them ideal for robotics and healthcare.However,existing sensors made from organic materials often fail under large tensile stresses and long-term bending,limiting their real-world applications.This paper presents the 100,000+cycle-reliable bending sensor(100k+CRBS),which leverages the flexibility and elastic response of an ultrathin piezoresistive silicon gauge integrated with highly resilient polyimide film by the water vapor plasma-assisted bonding method for both high robustness and reliability.The 100k+CRBSendured over 100,000 bending cycles at a radius of 5 mm.Additionally,it achieved a remarkable minimum bending radius of 0.4 mm.It also exhibited a mechanical limit of 300MPa,while maintaining stable operation below 94 MPa(<3%strain).These features enable precision motion capture in demanding applications including human-machine interaction,healthcare and rehabilitation,and smart industry and automation.展开更多
A simple and compact fiber bending sensor based on the Maeh-Zehnder interferometer was proposed. A photonic crystal fiber （PCF） with a length of 10mm was spliced by collapsing air holes with two conventional single ...A simple and compact fiber bending sensor based on the Maeh-Zehnder interferometer was proposed. A photonic crystal fiber （PCF） with a length of 10mm was spliced by collapsing air holes with two conventional single mode fibers to consist of an all fiber bending sensor. The sensitivity of 0.53nm/m-1 was obtained at 1586nm for the curvature range from 0 to 8.514 m-1. The temperature sensitivity was very low. The measurement error due to the temperature effect was about 8.68x10-3 m-1/℃, and the temperature effect in the curvature measurement could be ignored. This device can avoid the cross sensitivity of the temperature in the curvature measurement.展开更多
Vector bending sensing has been consistently growing in many fields.A low-cost and high sensitivity vector bending sensor based on a chirped long-period fiber grating[LPFG]with an off-axis micro helix taper is propose...Vector bending sensing has been consistently growing in many fields.A low-cost and high sensitivity vector bending sensor based on a chirped long-period fiber grating[LPFG]with an off-axis micro helix taper is proposed and experimentally demonstrated.The grating is composed of several sections of single-mode fiber with gradually larger lengths,and the off-axis micro helix tapers with fixed lengths when they are fabricated by using the arc discharge technology.The large refractive index modulation in the micro-helix taper greatly reduces the sensor size.The total length of the sensor is only 4.67 mm.The micro-helix taper-based LPFG can identify the bending direction due to the asymmetric structure introduced by the micro helix.The experimental results show that the transmission spectra of the sensor have distinct responses for different bending directions,and the maximum bending sensitivity is 14.08 nm/m^(-1)in the range from 0.128 m^(-1)to 1.28 m^(-1).The proposed bending sensor possesses pronounced advantages,such as high sensitivity,small size,low cost,and orientation identification,and offers a very promising method for bend measurement.展开更多
Flexible bending sensors have emerged as a technology with significant potential for a wide range of applications,including human-machine interaction,healthcare monitoring,and soft robotics.This paper provides a compr...Flexible bending sensors have emerged as a technology with significant potential for a wide range of applications,including human-machine interaction,healthcare monitoring,and soft robotics.This paper provides a comprehensive review of the working principles,performance evaluation,application areas,and future trends of flexible bending sensors.The challenges faced by these sensors,such as anti-interference,adaptive detection,and multidirectional sensing,are discussed,along with potential solutions and future developmental directions.The paper highlights the importance of materials development,structural design,and manufacturing processes in advancing flexible bending sensor technology.Overall,this review aims to provide valuable insights and guidance for further research and development in the field of flexible bending sensors.展开更多
The bending photonic crystal fiber grating sensor is an important role in underwater monitoring and fire alarm systems. It is studied that the resonant wavelength expression of bending long period photonic crystal fib...The bending photonic crystal fiber grating sensor is an important role in underwater monitoring and fire alarm systems. It is studied that the resonant wavelength expression of bending long period photonic crystal fiber gratings is deduced, it is designed that a bending long period photonic crystal fiber grating sensor system, it is calculated in theory that between the bending long period photonic crystal fiber gratings sensor resonance wavelength and the grating period and the bending strain. The result is shown by calculating and analysing in theory, the grating curvature is increased by the increase of the bending strain of the grating, and the resonance wavelength of the grating sensor is drifted, the drift amount is increased, one in this grating, the drifted amount of the resonant wavelength is 0.014 nm.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
Gesture recognition has diverse application prospects in the field of human-computer interaction.Recently,gesture recognition devices based on strain sensors have achieved remarkable results,among which liquid metal m...Gesture recognition has diverse application prospects in the field of human-computer interaction.Recently,gesture recognition devices based on strain sensors have achieved remarkable results,among which liquid metal materials have considerable advantages due to their high tensile strength and conductivity.To improve the detection sensitivity of liquid metal strain sensors,a sawtooth-enhanced bending sensor is proposed in this study.Compared with the results from previous studies,the bending sensor shows enhanced resistance variation.In addition,combined with machine learning algorithms,a gesture recognition glove based on the sawtooth-enhanced bending sensor is also fabricated in this study,and various gestures are accurately identified.In the fields of human-computer interaction,wearable sensing,and medical health,the sawtooth-enhanced bending sensor shows great potential and can have wide application prospects.展开更多
A multi-direction bending sensor based on spot pattern demodulation of a dual-hole fiber(DHF)is proposed.By using the interference and scattering in a DHF,the related multidirectional variations can be captured by the...A multi-direction bending sensor based on spot pattern demodulation of a dual-hole fiber(DHF)is proposed.By using the interference and scattering in a DHF,the related multidirectional variations can be captured by the optical field.Furthermore,the multi-directional bending characteristics of the fiber are quantitatively described by the pattern of the output light spot,achieving multidirectional bending sensing.In addition,considering the subtle changes in the deformation patterns over time,a convolutional neural network(CNN)model based on deep learning is introduced for accurate recognition and prediction of the bending angle.The experimental results show that the sensor can perceive different bending angles in four directions.These outstanding results indicate that the multi-directional bending sensor based on dual-hole interference pattern decoding has potential applications in multi-directional quantitative sensing and artificial intelligence perception.展开更多
Fiber Bragg grating(FBG)is the most widely used optical fiber sensor due to its compact size,high sensitivity,and easiness for multiplexing.Conventional FBGs fabricated by using an ultraviolet(UV)laser phase-mask meth...Fiber Bragg grating(FBG)is the most widely used optical fiber sensor due to its compact size,high sensitivity,and easiness for multiplexing.Conventional FBGs fabricated by using an ultraviolet(UV)laser phase-mask method require the sensitization of the optical fiber and could not be used at high temperatures.Recently,the fabrication of FBGs by using a femtosecond laser has attracted extensive interests due to its excellent flexibility in creating FBGs array or special FBGs with complex spectra.The femtosecond laser could also be used for inscribing various FBGs on almost all fiber types,even fibers without any photosensitivity.Such femtosecond-laser-induced FBGs exhibit excellent thermal stability,which is suitable for sensing in harsh environment.In this review,we present the historical developments and recent advances in the fabrication technologies and sensing applications of femtosecond-laser-inscribed FBGs.Firstly,the mechanism of femtosecond-laser-induced material modification is introduced.And then,three different fabrication tech no logies,i.e.,femtosecond laser phase mask technology,femtosecond laser holographic interferometry,and femtosecond laser direct writing technology,are discussed.Finally,the advances in high-temperature sensing applications and vector bending sensing applications of various femtosecond-laser-inscribed FBGs are summarized.Such femtosecond-laser-inscribed FBGs are promising in many industrial areas,such as aerospace vehicles,nuclear plants,oil and gas explorations,and advanced robotics in harsh environments.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12204271)Shenzhen Science and Technology Program(Grant No.JCYJ20220530141014032)Guangdong Basic and Applied Basic Research Foundation program(Grant No.2022A1515011526),China.
文摘In the era of Metaverse and virtual reality(VR)/augmented reality(AR),capturing finger motion and force interactions is crucial for immersive human-machine interfaces.This study introduces a flexible electronic skin for the index finger,addressing coupled perception of both state and process in dynamic tactile sensing.The device integrates resistive and giant magnetoelastic sensors,enabling detection of surface pressure and finger joint bending.This e-skin identifies three phases of finger action:bending state,dynamic normal force and tangential force(sweeping).The system comprises resistive carbon nanotubes(CNT)/polydimethylsiloxane(PDMS)films for bending sensing and magnetoelastic sensors(NdFeB particles,EcoFlex,and flexible coils)for pressure detection.The inward bending resistive sensor,based on self-assembled microstructures,exhibits directional specificity with a response time under 120 ms and bending sensitivity from 0°to 120°.The magnetoelastic sensors demonstrate specific responses to frequency and deformation magnitude,as well as sensitivity to surface roughness during sliding and material hardness.The system’s capability is demonstrated through tactile-based bread type and condition recognition,achieving 92%accuracy.This intelligent patch shows broad potential in enhancing interactions across various fields,from VR/AR interfaces and medical diagnostics to smart manufacturing and industrial automation.
基金supported by the National Natural Science Foundation of China(52105299,52175271,52375287)Science and Technology Development Plan Project of Jilin Province(20240101036JJ)+1 种基金Scientific Research Project of the Education Department of Jilin Province(JJKH20241269KJ)China Postdoctoral Science Foundation(2024M751086).
文摘In clinical work,many soft medical pipelines are located deep within the body,resulting in a lack of feedback regarding bending or folding conditions,which presents significant challenges for medical staff.To solve the problem,this study innovatively designs a flexible bending sensor,which can be attached to the medical pipelines and monitor the bending conditions.Based on a flexible substrate with secondary microstructures copied from champagne rose petals,the interdigital electrodes are designed to enhance the sensitivity of the sensor due to the amplifying effect.A high sensitivity of 2.209%?1in a bending strain range of 8.9%,and a stable repeatability for over 6000 cycles under 1.8%bending strain are achieved by the sensor.By integrating the bending sensor,here,the nasogastric tube,femoral vein catheter,and tracheal intubation are used to demonstrate the sensing performance.Additionally,during the measurement,the sensing signals are processed and transformed to the bending angles simultaneously,enabling the direct visualization of the bending conditions of the pipelines.This work proposes innovative applications for bending sensors in medical technology and establishes a foundation for further research on flexible bending sensors.
基金Project supported by the National Natural Science Foundation of China(Grant No.61705025)the Natural Science Foundation of Heilongjiang Province,China(Grant No.F2018027)+4 种基金the Fund from Chongqing Municipal Key Laboratory of Institutions of Higher Education(Grant No.20173)the Program of Chongqing Development and Reform Commission(Grant No.20171007)the Natural Science Foundation of Chongqing,China(Grant Nos.cstc2019jcyjmsxmX0431 and cstc2018jcyjAX0817)the Science and Technology Project Affiliated to the Education Department of Chongqing Municipality,China(Grant Nos.KJQN201801217,KJQN201901226,and KJ1710247)the Fundamental Research Funds for Chongqing Three Gorges University of China(Grant No.19ZDPY08)。
文摘A fiber cladding surface plasmon resonance(SPR)bending sensor is realized by the cladding of the fiber structure.By employing coating film,the sensing zone is protected and the toughness of the sensor increases.Three different sensing probes are tested,the experiment results indicate that the two parameters(wavelength sensitivity and light intensity sensitivity)sensing performances of the eccentric butt joint structures are superior to that of hetero-core structure,and the SPR bending sensor based on hetero-core structure is stable and uneasy to damage.By employing hetero-core fiber and silver film,a fiber cladding SPR bending sensor with better stabilization and sensing performance is realized.The proposed fabricating method of sensing probe with coating film provides a new approach for fiber SPR-distributed bending sensor.
基金supported by the Guangdong Province Key Field R&D Program Project(2020B0101110002)National Key R&D Program of China(2021YFB2800804)the National Natural Science Foundation of China(61905095,62101214).
文摘An exceptional-point(EP)enhanced fiber-optic bending sensor is reported.The sensor is implemented based on paritytime(PT)-symmetry using two coupled Fabry-Perot(FP)resonators consisting of three cascaded fiber Bragg gratings(FBGs)inscribed in an erbium-ytterbium co-doped fiber(EYDF).The EP is achieved by controlling the pumping power to manipulate the gain and loss of the gain and loss FP resonators.Once a bending force is applied to the gain FP resonator to make the operation of the system away from its EP,frequency splitting occurs,and the frequency spacing is a nonlinear function of the bending curvature,with an increased slope near the EP.Thus,by measuring the frequency spacing,the bending information is measured with increased sensitivity.To achieve high-speed and high-resolution interrogation,the optical spectral response of the sensor is converted to the microwave domain by implementing a dual-passband microwave-photonic filter(MPF),with the spacing between the two passbands equal to that of the frequency splitting.The proposed sensor is evaluated experimentally.A curvature sensing range from 0.28 to 2.74 m^(−1) is achieved with an accuracy of 7.56×10^(−4 )m^(−1 )and a sensitivity of 1.32 GHz/m^(−1),which is more than 4 times higher than those reported previously.
基金support by the Ministry of Education,Culture,Sports,Science and Technology(MEXT)under Grant[JPMXP1224UT1114]in part by the Japan Science and Technology Agency(JST)SPRING GX project of the University of Tokyo under Grant[JPMJSP2108]and JSPS KAKENHI Grant[24K17317]。
文摘Soft bending sensors offer high sensitivity and a large deformation range,making them ideal for robotics and healthcare.However,existing sensors made from organic materials often fail under large tensile stresses and long-term bending,limiting their real-world applications.This paper presents the 100,000+cycle-reliable bending sensor(100k+CRBS),which leverages the flexibility and elastic response of an ultrathin piezoresistive silicon gauge integrated with highly resilient polyimide film by the water vapor plasma-assisted bonding method for both high robustness and reliability.The 100k+CRBSendured over 100,000 bending cycles at a radius of 5 mm.Additionally,it achieved a remarkable minimum bending radius of 0.4 mm.It also exhibited a mechanical limit of 300MPa,while maintaining stable operation below 94 MPa(<3%strain).These features enable precision motion capture in demanding applications including human-machine interaction,healthcare and rehabilitation,and smart industry and automation.
基金This work was supported by the National Natural 1Science Foundation of China （NSFC） under Grants No. 61275125, 61007054, 61308055, National High Technology Research and Development Program of China under Grant No. 2013AA031501 ＆ 2012AA041203, Shenzhen Science and Technology Project （NO. JC201005280473A, JC201104210019A, ZDSY20120612094753264, JCYJ20130326113421781） and Specialized Research Fund for the Doctoral Program of Higher Education （SRFDP, 20124408120004）.Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author（s） and source are credited.
文摘A simple and compact fiber bending sensor based on the Maeh-Zehnder interferometer was proposed. A photonic crystal fiber （PCF） with a length of 10mm was spliced by collapsing air holes with two conventional single mode fibers to consist of an all fiber bending sensor. The sensitivity of 0.53nm/m-1 was obtained at 1586nm for the curvature range from 0 to 8.514 m-1. The temperature sensitivity was very low. The measurement error due to the temperature effect was about 8.68x10-3 m-1/℃, and the temperature effect in the curvature measurement could be ignored. This device can avoid the cross sensitivity of the temperature in the curvature measurement.
基金supported in part by the National Natural Science Foundation of China(NSFC)(Nos.62205087,62175049,and 62105077)Natural Science Foundation of Heilongjiang Province in China(No.YQ2021F002)+1 种基金Fundamental Research Funds for the Central Universities(Nos.3072022TS2501 and 3072021CFJ2504)China Postdoctoral Science Foundation(No.2022M710933)。
文摘Vector bending sensing has been consistently growing in many fields.A low-cost and high sensitivity vector bending sensor based on a chirped long-period fiber grating[LPFG]with an off-axis micro helix taper is proposed and experimentally demonstrated.The grating is composed of several sections of single-mode fiber with gradually larger lengths,and the off-axis micro helix tapers with fixed lengths when they are fabricated by using the arc discharge technology.The large refractive index modulation in the micro-helix taper greatly reduces the sensor size.The total length of the sensor is only 4.67 mm.The micro-helix taper-based LPFG can identify the bending direction due to the asymmetric structure introduced by the micro helix.The experimental results show that the transmission spectra of the sensor have distinct responses for different bending directions,and the maximum bending sensitivity is 14.08 nm/m^(-1)in the range from 0.128 m^(-1)to 1.28 m^(-1).The proposed bending sensor possesses pronounced advantages,such as high sensitivity,small size,low cost,and orientation identification,and offers a very promising method for bend measurement.
基金supported by the National Natural Science Foundation of China[52105563,52475573]Natural Science Foundation of Zhejiang Province[LTGY23E050002]+3 种基金National Key Research and Development Program of China[2023YFC2811500]Zhijiang Youth Project of Zhejiang Provincial Philosophy and Social Science Planning[22ZJQN14YB]Key Research and Development Programme of Zhejiang[2024C03259,2023C03196,2022C03103]Fundamental Research Funds for the Central Universities.
文摘Flexible bending sensors have emerged as a technology with significant potential for a wide range of applications,including human-machine interaction,healthcare monitoring,and soft robotics.This paper provides a comprehensive review of the working principles,performance evaluation,application areas,and future trends of flexible bending sensors.The challenges faced by these sensors,such as anti-interference,adaptive detection,and multidirectional sensing,are discussed,along with potential solutions and future developmental directions.The paper highlights the importance of materials development,structural design,and manufacturing processes in advancing flexible bending sensor technology.Overall,this review aims to provide valuable insights and guidance for further research and development in the field of flexible bending sensors.
文摘The bending photonic crystal fiber grating sensor is an important role in underwater monitoring and fire alarm systems. It is studied that the resonant wavelength expression of bending long period photonic crystal fiber gratings is deduced, it is designed that a bending long period photonic crystal fiber grating sensor system, it is calculated in theory that between the bending long period photonic crystal fiber gratings sensor resonance wavelength and the grating period and the bending strain. The result is shown by calculating and analysing in theory, the grating curvature is increased by the increase of the bending strain of the grating, and the resonance wavelength of the grating sensor is drifted, the drift amount is increased, one in this grating, the drifted amount of the resonant wavelength is 0.014 nm.
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supported by the National Key R&D Program of China(Grant No.2022YFC2403703)。
文摘Gesture recognition has diverse application prospects in the field of human-computer interaction.Recently,gesture recognition devices based on strain sensors have achieved remarkable results,among which liquid metal materials have considerable advantages due to their high tensile strength and conductivity.To improve the detection sensitivity of liquid metal strain sensors,a sawtooth-enhanced bending sensor is proposed in this study.Compared with the results from previous studies,the bending sensor shows enhanced resistance variation.In addition,combined with machine learning algorithms,a gesture recognition glove based on the sawtooth-enhanced bending sensor is also fabricated in this study,and various gestures are accurately identified.In the fields of human-computer interaction,wearable sensing,and medical health,the sawtooth-enhanced bending sensor shows great potential and can have wide application prospects.
基金supported by the Basic and Applied Basic Research Foundation of Guangdong Province(No.2022A1515110480)the National Natural Science Foundation of China(No.62205057)the Dongguan Science and Technology of Social Development Program(No.20231800903222).
文摘A multi-direction bending sensor based on spot pattern demodulation of a dual-hole fiber(DHF)is proposed.By using the interference and scattering in a DHF,the related multidirectional variations can be captured by the optical field.Furthermore,the multi-directional bending characteristics of the fiber are quantitatively described by the pattern of the output light spot,achieving multidirectional bending sensing.In addition,considering the subtle changes in the deformation patterns over time,a convolutional neural network(CNN)model based on deep learning is introduced for accurate recognition and prediction of the bending angle.The experimental results show that the sensor can perceive different bending angles in four directions.These outstanding results indicate that the multi-directional bending sensor based on dual-hole interference pattern decoding has potential applications in multi-directional quantitative sensing and artificial intelligence perception.
基金supported by National Natural Science Foundation of China(NSFC)(Grant Nos.U1913212,61875128,and 61635007)Department of Science and Technology of Guangdong Province(Grant Nos.2019TQ05X113,2019A1515011393,2019B1515120042,and 2019A1515111114)Shenzhen Science and Technology Program(Grant Nos.RCYX20200714114538160 and JCYJ20180507182058432).
文摘Fiber Bragg grating(FBG)is the most widely used optical fiber sensor due to its compact size,high sensitivity,and easiness for multiplexing.Conventional FBGs fabricated by using an ultraviolet(UV)laser phase-mask method require the sensitization of the optical fiber and could not be used at high temperatures.Recently,the fabrication of FBGs by using a femtosecond laser has attracted extensive interests due to its excellent flexibility in creating FBGs array or special FBGs with complex spectra.The femtosecond laser could also be used for inscribing various FBGs on almost all fiber types,even fibers without any photosensitivity.Such femtosecond-laser-induced FBGs exhibit excellent thermal stability,which is suitable for sensing in harsh environment.In this review,we present the historical developments and recent advances in the fabrication technologies and sensing applications of femtosecond-laser-inscribed FBGs.Firstly,the mechanism of femtosecond-laser-induced material modification is introduced.And then,three different fabrication tech no logies,i.e.,femtosecond laser phase mask technology,femtosecond laser holographic interferometry,and femtosecond laser direct writing technology,are discussed.Finally,the advances in high-temperature sensing applications and vector bending sensing applications of various femtosecond-laser-inscribed FBGs are summarized.Such femtosecond-laser-inscribed FBGs are promising in many industrial areas,such as aerospace vehicles,nuclear plants,oil and gas explorations,and advanced robotics in harsh environments.
