A metal-sensitive diaphragm fiber optic pressure sensor with temperature compensation is developed for pressure monitoring in high-temperature environments,such as engine fuel systems,oil and gas wells,and aviation hy...A metal-sensitive diaphragm fiber optic pressure sensor with temperature compensation is developed for pressure monitoring in high-temperature environments,such as engine fuel systems,oil and gas wells,and aviation hydraulic systems.The sensor combines a metal-sensitive diaphragm and a sapphire wafer to form a temperature-pressure dual Fabry-Perot(FP)interference cavity.A cross-correlation signal demodulation algorithm and a temperature decoupling method are utilized to reduce the influence of temperature crosstalk on pressure measurement.Experimental results show that the maximum nonlinear error of the sensor pressure measurement is 0.75%full scale(FS)and 0.99%FS at room temperature and 300°C,respectively,in a pressure range of 0−10 MPa and 0−1.5 MPa.The sensor’s pressure measurement accuracy is 1.7%FS when using the temperature decoupling method.The sensor exhibits good static pressure characteristics,stability,and reliability,providing an effective solution for high-temperature pressure monitoring applications.展开更多
The development of intelligent electronic power systems necessitates advanced flexible pressure sensors.Despite improved compressibility through surface micro-structures or bulk pores,conventional capacitive pressure ...The development of intelligent electronic power systems necessitates advanced flexible pressure sensors.Despite improved compressibility through surface micro-structures or bulk pores,conventional capacitive pressure sensors face limitations due to their low dielectric constant and poor temperature tolerance of most elastomers.Herein,we constructed oriented polyimide-based aerogels with mechanical robustness and notable changes in dielectric constant under compression.The enhancement is attributed to the doping of surface-modified dielectric nanoparticles and graphene oxide sheets,which interact with polymer molecular chains.The resulting aerogels,with their excellent temperature resistance,were used to assemble high-performance capacitive pressure sensors.The sensor exhibits a maximum sensitivity of 1.41 kPa^(−1)over a wide working range of 0-200 kPa.Meanwhile,the sensor can operate in environments up to 150℃during 2000 compression/release cycles.Furthermore,the aerogel-based sensor demonstrates proximity sensing capabilities,showing great potential for applications in non-contact sensing and extreme environment detection.展开更多
A compact and highly sensitive gas pressure and temperature sensor based on Fabry-Pérot interferometer(FPI)and fiber Bragg grating(FBG)is proposed and demonstrated experimentally in this paper.The theoretical mod...A compact and highly sensitive gas pressure and temperature sensor based on Fabry-Pérot interferometer(FPI)and fiber Bragg grating(FBG)is proposed and demonstrated experimentally in this paper.The theoretical model for pressure and temperature sensing is established.Building on this foundation,a novel micro silicon cavity sensor structure sensitive to pressure is devised downstream of an FBG.The concept of separate measurement and the mechanisms enhancing pressure sensitivity are meticulously analyzed,and the corresponding samples are fabricated.The experimental results indicate that the pressure sensitivity of the sensor is-747.849 nm/MPa in 0—100 k Pa and its linearity is 99.7%and it maintains good stability in 150 min.The sensor offers the advantages of compact size,robust construction,easy fabrication,and high sensitivity,making it potentially valuable for micro-pressure application.展开更多
Capacitive pressure sensors have a promising application in the field of wearable electronic devices due to their excellent electrical properties.Owing to the complexity of the environment,capacitive sensors are susce...Capacitive pressure sensors have a promising application in the field of wearable electronic devices due to their excellent electrical properties.Owing to the complexity of the environment,capacitive sensors are susceptible to electromagnetic interference and changes in the surrounding medium,resulting in unstable signal acquisition.Capacitive sensor with excellent immunity to interference while maintaining flexibility is an urgent challenge.This study proposes an all-fiber anti-jamming capacitive pressure sensor that integrates liquid metal(LM)into a fiber-based dielectric layer.The combination of the LM and the fiber not only improves the dielectric properties of the dielectric layer but also reduces the Young's modulus of the fiber.The sensor has high interference immunity in various noise environments.Its all-fiber structure ensures lightweight,great air permeability and stretchability,whichmakes it a promising application in wearable electronic devices fields.展开更多
In recent decades,capacitive pressure sensors(CPSs)with high sensitivity have demonstrated significant potential in applications such as medical monitoring,artificial intelligence,and soft robotics.Efforts to enhance ...In recent decades,capacitive pressure sensors(CPSs)with high sensitivity have demonstrated significant potential in applications such as medical monitoring,artificial intelligence,and soft robotics.Efforts to enhance this sensitivity have predominantly focused on material design and structural optimization,with surface microstructures such as wrinkles,pyramids,and micro-pillars proving effective.Although finite element modeling(FEM)has guided enhancements in CPS sensitivity across various surface designs,a theoretical understanding of sensitivity improvements remains underexplored.This paper employs sinusoidal wavy surfaces as a representative model to analytically elucidate the underlying mechanisms of sensitivity enhancement through contact mechanics.These theoretical insights are corroborated by FEM and experimental validations.Our findings underscore that optimizing material properties,such as Young’s modulus and relative permittivity,alongside adjustments in surface roughness and substrate thickness,can significantly elevate the sensitivity.The optimal performance is achieved when the amplitude-to-wavelength ratio(H/)is about 0.2.These results offer critical insights for designing ultrasensitive CPS devices,paving the way for advancements in sensor technology.展开更多
The Design and manufacturing of a noble piezoresistive pressure sensor(PS) for subtle pressures(<1 kPa) were presented. Meanwhile, in the studies conducted in the field of pressure sensors, the measurement of subtl...The Design and manufacturing of a noble piezoresistive pressure sensor(PS) for subtle pressures(<1 kPa) were presented. Meanwhile, in the studies conducted in the field of pressure sensors, the measurement of subtle pressures has received less attention. The limitations in the inherent gauge factor in silicon, have led to the development of polymer and composite resistive sensitive elements. However,in the development of resistance sensing elements, the structure of composite elements with reinforcement core has not been used. The proposed PS had a composite sandwich structure consisting of a nanocomposite graphene layer covered by layers of PDMS at the bottom and on the top coupled with a polyimide(PI) core. Various tests were performed to analyze the PS. The primary design target was improved sensitivity, with a finite-element method(FEM) utilized to simulate the stress profile over piezoresistive elements and membrane deflection at various pressures. The PS manufacturing process is based on Laser-engraved graphene(LEG) technology and PDMS casting. Experimental data indicated that the manufactured PS exhibits a sensitivity of 67.28 mV/kPa for a pressure range of 30-300 Pa in ambient temperature.展开更多
Flexible piezoresistive pressure sensors have attracted much attention for applications in health monitoring and human-machine interfaces due to their simple device structures and easy-to-read signals.For practical ap...Flexible piezoresistive pressure sensors have attracted much attention for applications in health monitoring and human-machine interfaces due to their simple device structures and easy-to-read signals.For practical applications,the deployment of flexible pressure sensors characterized by high sensitivity and fast response time is imperative for the rapid and accurate detection and monitoring of tiny signals.Such capabilities are essential for facilitating immediate feedback and informed decision-making across a spectrum of contexts.Drawing lessons from the hypersensitive and fast-responding pressure sensing structures in the dragonfly’s neck(for stable imaging during its highly maneuverable flight),a Biomimetic Piezoresistive Pressure Sensor(BPPS)with exquisite mechanically interlocking sensing microstructures is developed.Each interlocking perceptual structure pair consists of an ox-horn-shaped and a mushroom-shaped structural unit.Through the characteristic configuration of the perceptual structure pair,the BPPS realizes a fast gradient accumulation of the contact area,thus synergistically enhancing the sensitivity and fast response capability.Remarkably,the sensitivity of the BPPS reaches 0.35 kPa^(−1),which increased by 75%compared to the 0.2 kPa^(−1) of the pressure sensors without biomimetic structures.Moreover,the BPPS also achieves rapid response/recovery times(<90/15 ms).Our BPPS finds utility in tasks such as identifying objects of different weights,monitoring human respiratory status,and tracking motion,demonstrating its potential in wearable healthcare devices,assistive technology,and intelligent soft robotics.Moreover,it possesses the advantages of high sensitivity and fast response time in practical applications.展开更多
Pressure sensors are essential for a wide range of applica-tions,including health monitoring,industrial diagnostics,etc.However,achieving both high sensitivity and mechanical ability to withstand high pressure in a si...Pressure sensors are essential for a wide range of applica-tions,including health monitoring,industrial diagnostics,etc.However,achieving both high sensitivity and mechanical ability to withstand high pressure in a single material remains a significant challenge.This study introduces a high-performance cellulose hydrogel inspired by the biomi-metic layered porous structure of human skin.The hydrogel features a novel design composed of a soft layer with large macropores and a hard layer with small micropores,each of which contribute uniquely to its pressure-sensing capabilities.The macropores in the soft part facilitate significant deforma-tion and charge accumulation,providing exceptional sensitivity to low pressures.In contrast,the microporous structure in the hard part enhances pressure range,ensuring support under high pressures and preventing structural failure.The performance of hydrogel is further optimized through ion introduction,which improves its conductivity,and as well the sensitivity.The sensor demonstrated a high sensitivity of 1622kPa^(-1),a detec-tion range up to 160 kPa,excellent conductivity of 4.01 Sm^(-1),rapid response time of 33 ms,and a low detection limit of 1.6 Pa,outperforming most existing cellulose-based sensors.This innovative hierarchically porous architecture not only enhances the pressure-sensing performance but also offers a simple and effective approach for utilizing natural polymers in sensing technologies.The cellulose hydrogel demonstrates sig-nificant potential in both health monitoring and industrial applications,providing a sensitive,durable,and versatile solution for pressure sensing.展开更多
Flexible pressure sensors show great promise for applications in such fields as electronic skin,healthcare,and intelligent robotics.Traditional capacitive pressure sensors,however,face the problem of low sensitivity,w...Flexible pressure sensors show great promise for applications in such fields as electronic skin,healthcare,and intelligent robotics.Traditional capacitive pressure sensors,however,face the problem of low sensitivity,which limits their wider application.In this paper,a flexible capacitive pressure sensor with microstructured ionization layer is fabricated by a sandwich-type process,with a low-cost and simple process of inverted molding with sandpapers being used to form a thermoplastic polyurethane elastomer ionic film with double-sided microstructure as the dielectric layer of the sensor,with silver nanowires as electrodes.The operating mechanism of this iontronic pressure sensor is analyzed using a graphical method,and the sensor is tested on a pressure platform.The test results show that the sensor has ultrahigh pressure sensitivities of 3.744 and 1.689 kPa^(−1) at low(0-20 kPa)and high(20-800 kPa)pressures,respectively,as well as a rapid response time(100 ms),and it exhibits good stability and repeatability.The sensor can be used for sensitive monitoring of activities such as finger bending,and for facial expression(smile,frown)recognition,as well as speech recognition.展开更多
Implantable temperature sensors are revolutionizing physiological monitoring and playing a crucial role in diagnostics,therapeutics,and life sciences research.This review classifies the materials used in these sensors...Implantable temperature sensors are revolutionizing physiological monitoring and playing a crucial role in diagnostics,therapeutics,and life sciences research.This review classifies the materials used in these sensors into three categories:metal-based,inorganic semiconductor,and organic semiconductor materials.Metal-based materials are widely used in medical and industrial applications due to their linearity,stability,and reliability.Inorganic semiconductors provide rapid response times and high miniaturization potential,making them promising for biomedical and environmental monitoring.Organic semiconductors offer high sensitivity and ease of processing,enabling the development of flexible and stretchable sensors.This review analyzes recent studies for each material type,covering design principles,performance characteristics,and applications,highlighting key advantages and challenges regarding miniaturization,sensitivity,response time,and biocompatibility.Furthermore,critical performance parameters of implantable temperature sensors based on different material types are summarized,providing valuable references for future sensor design and optimization.The future development of implantable temperature sensors is discussed,focusing on improving biocompatibility,long-term stability,and multifunctional integration.These advancements are expected to expand the application potential of implantable sensors in telemedicine and dynamic physiological monitoring.展开更多
The emergence of two-dimensional nanomaterials,especially MXene,significantly overcomes the limitations of flexible pressure sensors regarding their sensing abilities,mechanical properties,and electromagnetic shieldin...The emergence of two-dimensional nanomaterials,especially MXene,significantly overcomes the limitations of flexible pressure sensors regarding their sensing abilities,mechanical properties,and electromagnetic shielding effectiveness.This advancement underscores their great potential for use in wearable and medical monitoring devices.However,single-layer MXene is highly prone to oxidation when exposed to air and tends to stack between layers.Combining MXene with other functional materials to create heterojunction structures effectively addresses the stacking problem while also providing the resulting composites with excellent electrical conductivity,mechanical flexibility,and electromagnetic shielding capabilities,which are essential for enhancing sensor performance.This review systematically outlines various microstructural designs and improvement strategies aimed at boosting the sensing efficiency of different flexible pressure sensors based on MXene.It offers a comprehensive analysis of their significance in medical monitoring,anticipates future challenges and opportunities,and serves as an important reference for advancing precision and personalized approaches in medical monitoring.展开更多
Microelectromechanical system(MEMS)high-temperature pressure sensors are widely used in aerospace,petrochemical industries,automotive electronics,and other fields owing to their advantages of miniaturization,lightweig...Microelectromechanical system(MEMS)high-temperature pressure sensors are widely used in aerospace,petrochemical industries,automotive electronics,and other fields owing to their advantages of miniaturization,lightweight design,simplified signal processing,and high accuracy.In recent years,advances in semiconductor material growth technology and intelligent equipment operation have significantly increased interest in high-temperature pressure sensors based on the third-generation semiconductor silicon carbide(SiC).This review examines the material properties of SiC single crystals and discusses several technologies influencing the performance of SiC pressure sensors,including the piezoresistive effect,ohmic contact,etching processes,and packaging methodologies.Additionally,it explores future research directions in the field.The review highlights the importance of increasing operating temperatures and advancing sensor integration as critical trends for future SiC high-temperature pressure sensor research and applications.展开更多
Extreme environments challenge the structural health monitoring of advanced equipment.In-situ dynamic tracking temperature is of particular value due to its enormous impact on material properties.However,the realizati...Extreme environments challenge the structural health monitoring of advanced equipment.In-situ dynamic tracking temperature is of particular value due to its enormous impact on material properties.However,the realization of such integrated temperature sensors typically requires complicated layer-by-layer molding and sintering processes including additional thermal barrier coatings.Herein,we report a laser-induced in-situ conductive passivation strategy for the fabrication of a thin-film based wide-range temperature sensor.The instantaneous thermal effect of laser irradiation creates crystalline conductive traces in response to temperature variations.Synchronously,it also allows the formation of an amorphous antioxidative layer without necessitating extra protective coatings.Such configuration enables precise real-time sensing across-50℃to 950℃following the Steinhart-Hart equation.It also exhibits durable performance with only 1.2%drift over 20 hours during long-term high-temperature,instant thermal shock,frequent wearing,and severe vibration.This in-situ,facile laser manufacturing strategy holds great promise in structural health monitoring and fault diagnosis for advanced equipment working in extreme environments.展开更多
Multimodal information sensing becomes increasingly critical under the rapid development of automation and information technology.With the ability to provide high-density and high-sensitivity pressure detection,pressu...Multimodal information sensing becomes increasingly critical under the rapid development of automation and information technology.With the ability to provide high-density and high-sensitivity pressure detection,pressure sensor arrays have been applied to a variety of fields,including intelligent robotics,medical monitoring,and industrial automation.This study proposes a pressure sensor array system based on the Minecraft game platform.The simulation and testing of the pressure sensor arrays system have been conducted using redstone circuits and pressure plates in Minecraft to simulate real-world piezoelectric pressure sensor arrays.A series of experiments verified the feasibility and effectiveness of the system.展开更多
Laser-Induced Graphene (LIG) is regarded as a promising sensor carrier due to its inherent three-dimensional porous structure. However, as two mutually exclusive properties of the pressure sensor, sensitivity and work...Laser-Induced Graphene (LIG) is regarded as a promising sensor carrier due to its inherent three-dimensional porous structure. However, as two mutually exclusive properties of the pressure sensor, sensitivity and working range are difficult to be further improved by the single porous structure. Inspired by the unique geometry of Oxalis corniculata L. leaves, we here propose a novel method consist of laser pre-etching and inducing steps to fabricate LIG-based electrodes with a two-stage architecture featuring microjigsaw and microporous structures. The following injection of liquid-silicone significantly improves the friction resistance and bending reliability of LIG materials. The interface contact between external microjigsaw structures induces substantial resistance changes, and the internal microporous structure exhibits reversibility during dynamic deformation. Consequently, the jigsaw-like pressure sensor achieves a balanced performance with sensitivities of 3.64, 1.20 and 0.03 kPa^(- 1) in pressure range of 0 -20, 20 - 40 and 40 - 150 kPa, respectively. The bionic LIG-based pressure sensor serves as the core component and further integrated with an all-in-one wireless transmission system capable of monitoring various health parameters such as subtle pulse rates, heartbeat rhythms, sounds, etc., indicating broad prospects in future wearable electronics.展开更多
High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneous...High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneously achieve high sensitivity,a wide detection range,and good mechanical stability remains a challenge.In this paper,we propose a flexible piezoresistive pressure sensor based on a Ti_(3)C_(2)Tx(MXene)/polyethylene oxide(PEO)composite nanofiber membrane(CNM).The sensor,utilizing MXene(0.4 wt%)/PEO(5 wt%),exhibits high sensitivity(44.34 kPa^(−1)at 0−50 kPa,12.99 kPa^(−1)at 50−500 kPa)and can reliably monitor physiological signals and other subtle cues.Moreover,the sensor features a wide detection range(0−500 kPa),fast response and recovery time(~150/45 ms),and excellent mechanical stability(over 10000 pressure cycles at maximum load).Through an MXene/PEO sensor array,we demonstrate its applications in human physiological signal monitoring,providing a reliable way to expand the application of MXene-based flexible pressure sensors.展开更多
Wearable pressure sensors capable of adhering comfortably to the skin hold great promise in sound detection.However,current intelligent speech assistants based on pressure sensors can only recognize standard languages...Wearable pressure sensors capable of adhering comfortably to the skin hold great promise in sound detection.However,current intelligent speech assistants based on pressure sensors can only recognize standard languages,which hampers effective communication for non-standard language people.Here,we prepare an ultralight Ti_(3)C_(2)T_(x)MXene/chitosan/polyvinylidene difluoride composite aerogel with a detection range of 6.25 Pa-1200 k Pa,rapid response/recovery time,and low hysteresis(13.69%).The wearable aerogel pressure sensor can detect speech information through the throat muscle vibrations without any interference,allowing for accurate recognition of six dialects(96.2%accuracy)and seven different words(96.6%accuracy)with the assistance of convolutional neural networks.This work represents a significant step forward in silent speech recognition for human–machine interaction and physiological signal monitoring.展开更多
We proposed a fiber optic high temperature sensor based on the Mach-Zehnder interference(MZI)structure,which is composed of two lengths of multi-mode fibers(MMFs),a length of few-mode fiber(FMF)and two sections of sin...We proposed a fiber optic high temperature sensor based on the Mach-Zehnder interference(MZI)structure,which is composed of two lengths of multi-mode fibers(MMFs),a length of few-mode fiber(FMF)and two sections of single-mode fibers(SMFs).Firstly,the two sections of MMFs were spliced with two sections of SMFs.Then,the MMFs were fused to two ends of FMF to form a symmetrically structured fiber-optic MZI structure.In this structure,the MMF served as the optical mode field coupling element,and the cladding and core of the FMF are the interference arm and the reference arm of the MZI structure,respectively.We investigated the sensor's response characteristics of the temperature and strain.The experimental results indicate that the sensor is sensitive to temperature variation,and the temperature response sensitivity is up to 61.4 pm/℃ in the range of 40-250℃,while the sensor has weak strain sensitivity,its strain sensitivity is only-0.72 pm/μe in the strain range of 0-1400μe.Moreover,the sensor has good stability and repeatability.In brief,the proposed fiber optic high temperature sensor has good properties,such as high sensitivity,compact structure,good stability and repeatability,which can be used for monitoring the temperature of submerged oil electric pump units under oil wells.展开更多
Flexible and wearable pressure sensors hold immense promise for health monitoring,covering disease detection and postoperative rehabilitation.Developing pressure sensors with high sensitivity,wide detection range,and ...Flexible and wearable pressure sensors hold immense promise for health monitoring,covering disease detection and postoperative rehabilitation.Developing pressure sensors with high sensitivity,wide detection range,and cost-effectiveness is paramount.By leveraging paper for its sustainability,biocompatibility,and inherent porous structure,herein,a solution-processed all-paper resistive pressure sensor is designed with outstanding performance.A ternary composite paste,comprising a compressible 3D carbon skeleton,conductive polymer poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate),and cohesive carbon nanotubes,is blade-coated on paper and naturally dried to form the porous composite electrode with hierachical micro-and nano-structured surface.Combined with screen-printed Cu electrodes in submillimeter finger widths on rough paper,this creates a multiscale hierarchical contact interface between electrodes,significantly enhancing sensitivity(1014 kPa-1)and expanding the detection range(up to 300 kPa)of as-resulted all-paper pressure sensor with low detection limit and power consumption.Its versatility ranges from subtle wrist pulses,robust finger taps,to large-area spatial force detection,highlighting its intricate submillimetermicrometer-nanometer hierarchical interface and nanometer porosity in the composite electrode.Ultimately,this all-paper resistive pressure sensor,with its superior sensing capabilities,large-scale fabrication potential,and cost-effectiveness,paves the way for next-generation wearable electronics,ushering in an era of advanced,sustainable technological solutions.展开更多
Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibe...Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibers/polypyrrole/nickel(APN)aerogels,which serve dual roles as both microwave absorbers and pressure sensors.In this work,we focused on the preparation of aramid nanofibers/polypyrrole(AP15)aerogels,where the mass ratio of aramid nanofibers to pyrrole was 1:5.We employed the oxidative polymerization method for the preparation process.Following this,nickel was thermally evaporated onto the surface of the AP15 aerogels,resulting in the creation of an ultralight(9.35 mg·cm^(-3)).This aerogel exhibited a porous structure.The introduction of nickel into the aerogel aimed to enhance magnetic loss and adjust impedance matching,thereby improving electromagnetic wave absorption performance.The minimum reflection loss value achieved was-48.7 dB,and the maximum effective absorption bandwidth spanned 8.42 GHz with a thickness of 2.9 mm.These impressive metrics can be attributed to the three-dimensional network porous structure of the aerogel and perfect impedance matching.Moreover,the use of aramid nanofibers and a three-dimensional hole structure endowed the APN aerogels with good insulation,flame-retardant properties,and compression resilience.Even under a compression strain of 50%,the aerogel maintained its resilience over 500 cycles.The incorporation of polypyrrole and nickel particles further enhanced the conductivity of the aerogel.Consequently,the final APN aerogel sensor demonstrated high sensitivity(10.78 kPa-1)and thermal stability.In conclusion,the APN aerogels hold significant promise as ultra-broadband microwave absorbers and pressure sensors.展开更多
文摘A metal-sensitive diaphragm fiber optic pressure sensor with temperature compensation is developed for pressure monitoring in high-temperature environments,such as engine fuel systems,oil and gas wells,and aviation hydraulic systems.The sensor combines a metal-sensitive diaphragm and a sapphire wafer to form a temperature-pressure dual Fabry-Perot(FP)interference cavity.A cross-correlation signal demodulation algorithm and a temperature decoupling method are utilized to reduce the influence of temperature crosstalk on pressure measurement.Experimental results show that the maximum nonlinear error of the sensor pressure measurement is 0.75%full scale(FS)and 0.99%FS at room temperature and 300°C,respectively,in a pressure range of 0−10 MPa and 0−1.5 MPa.The sensor’s pressure measurement accuracy is 1.7%FS when using the temperature decoupling method.The sensor exhibits good static pressure characteristics,stability,and reliability,providing an effective solution for high-temperature pressure monitoring applications.
基金financially supported by the National Key Research&Development Program of China(No.2022YFA1205200).
文摘The development of intelligent electronic power systems necessitates advanced flexible pressure sensors.Despite improved compressibility through surface micro-structures or bulk pores,conventional capacitive pressure sensors face limitations due to their low dielectric constant and poor temperature tolerance of most elastomers.Herein,we constructed oriented polyimide-based aerogels with mechanical robustness and notable changes in dielectric constant under compression.The enhancement is attributed to the doping of surface-modified dielectric nanoparticles and graphene oxide sheets,which interact with polymer molecular chains.The resulting aerogels,with their excellent temperature resistance,were used to assemble high-performance capacitive pressure sensors.The sensor exhibits a maximum sensitivity of 1.41 kPa^(−1)over a wide working range of 0-200 kPa.Meanwhile,the sensor can operate in environments up to 150℃during 2000 compression/release cycles.Furthermore,the aerogel-based sensor demonstrates proximity sensing capabilities,showing great potential for applications in non-contact sensing and extreme environment detection.
基金supported in part by the National Natural Science Foundation of China(Nos.61735014 and 61927812)the Shaanxi Provincial Education Department(No.18JS093)+2 种基金the Natural Science Basic Research Program of Shaanxi Province(No.2024JC-YBMS-530)the Operation Fund of Logging Key Laboratory of Group Company(No.2021DQ0107-11)the Graduate Student Innovation Fund of Xi’an Shiyou University(No.YCS23213193)。
文摘A compact and highly sensitive gas pressure and temperature sensor based on Fabry-Pérot interferometer(FPI)and fiber Bragg grating(FBG)is proposed and demonstrated experimentally in this paper.The theoretical model for pressure and temperature sensing is established.Building on this foundation,a novel micro silicon cavity sensor structure sensitive to pressure is devised downstream of an FBG.The concept of separate measurement and the mechanisms enhancing pressure sensitivity are meticulously analyzed,and the corresponding samples are fabricated.The experimental results indicate that the pressure sensitivity of the sensor is-747.849 nm/MPa in 0—100 k Pa and its linearity is 99.7%and it maintains good stability in 150 min.The sensor offers the advantages of compact size,robust construction,easy fabrication,and high sensitivity,making it potentially valuable for micro-pressure application.
基金financially supported by the National Natural Science Foundation of China(Nos.U20A20166,52371202,52125205,52250398,52192614 and 52003101)the National Key R&D Program of China(No.2021YFB3200300)+2 种基金the Natural Science Foundation of Beijing Municipality(No.2222088)Shenzhen Science and Technology Program(No.KQTD20170810105439418)the Fundamental Research Funds for the Central Universities
文摘Capacitive pressure sensors have a promising application in the field of wearable electronic devices due to their excellent electrical properties.Owing to the complexity of the environment,capacitive sensors are susceptible to electromagnetic interference and changes in the surrounding medium,resulting in unstable signal acquisition.Capacitive sensor with excellent immunity to interference while maintaining flexibility is an urgent challenge.This study proposes an all-fiber anti-jamming capacitive pressure sensor that integrates liquid metal(LM)into a fiber-based dielectric layer.The combination of the LM and the fiber not only improves the dielectric properties of the dielectric layer but also reduces the Young's modulus of the fiber.The sensor has high interference immunity in various noise environments.Its all-fiber structure ensures lightweight,great air permeability and stretchability,whichmakes it a promising application in wearable electronic devices fields.
基金supported by the National Natural Science Foundation of China(Grant No.12272369)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0620101).
文摘In recent decades,capacitive pressure sensors(CPSs)with high sensitivity have demonstrated significant potential in applications such as medical monitoring,artificial intelligence,and soft robotics.Efforts to enhance this sensitivity have predominantly focused on material design and structural optimization,with surface microstructures such as wrinkles,pyramids,and micro-pillars proving effective.Although finite element modeling(FEM)has guided enhancements in CPS sensitivity across various surface designs,a theoretical understanding of sensitivity improvements remains underexplored.This paper employs sinusoidal wavy surfaces as a representative model to analytically elucidate the underlying mechanisms of sensitivity enhancement through contact mechanics.These theoretical insights are corroborated by FEM and experimental validations.Our findings underscore that optimizing material properties,such as Young’s modulus and relative permittivity,alongside adjustments in surface roughness and substrate thickness,can significantly elevate the sensitivity.The optimal performance is achieved when the amplitude-to-wavelength ratio(H/)is about 0.2.These results offer critical insights for designing ultrasensitive CPS devices,paving the way for advancements in sensor technology.
文摘The Design and manufacturing of a noble piezoresistive pressure sensor(PS) for subtle pressures(<1 kPa) were presented. Meanwhile, in the studies conducted in the field of pressure sensors, the measurement of subtle pressures has received less attention. The limitations in the inherent gauge factor in silicon, have led to the development of polymer and composite resistive sensitive elements. However,in the development of resistance sensing elements, the structure of composite elements with reinforcement core has not been used. The proposed PS had a composite sandwich structure consisting of a nanocomposite graphene layer covered by layers of PDMS at the bottom and on the top coupled with a polyimide(PI) core. Various tests were performed to analyze the PS. The primary design target was improved sensitivity, with a finite-element method(FEM) utilized to simulate the stress profile over piezoresistive elements and membrane deflection at various pressures. The PS manufacturing process is based on Laser-engraved graphene(LEG) technology and PDMS casting. Experimental data indicated that the manufactured PS exhibits a sensitivity of 67.28 mV/kPa for a pressure range of 30-300 Pa in ambient temperature.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)National Natural Science Foundation of China(Nos.52222509,52105301)+1 种基金the Natural Science Foundation of Jilin Province(Grant No.20220101220JC)supported by“Fundamental Research Funds for the Central Universities”.
文摘Flexible piezoresistive pressure sensors have attracted much attention for applications in health monitoring and human-machine interfaces due to their simple device structures and easy-to-read signals.For practical applications,the deployment of flexible pressure sensors characterized by high sensitivity and fast response time is imperative for the rapid and accurate detection and monitoring of tiny signals.Such capabilities are essential for facilitating immediate feedback and informed decision-making across a spectrum of contexts.Drawing lessons from the hypersensitive and fast-responding pressure sensing structures in the dragonfly’s neck(for stable imaging during its highly maneuverable flight),a Biomimetic Piezoresistive Pressure Sensor(BPPS)with exquisite mechanically interlocking sensing microstructures is developed.Each interlocking perceptual structure pair consists of an ox-horn-shaped and a mushroom-shaped structural unit.Through the characteristic configuration of the perceptual structure pair,the BPPS realizes a fast gradient accumulation of the contact area,thus synergistically enhancing the sensitivity and fast response capability.Remarkably,the sensitivity of the BPPS reaches 0.35 kPa^(−1),which increased by 75%compared to the 0.2 kPa^(−1) of the pressure sensors without biomimetic structures.Moreover,the BPPS also achieves rapid response/recovery times(<90/15 ms).Our BPPS finds utility in tasks such as identifying objects of different weights,monitoring human respiratory status,and tracking motion,demonstrating its potential in wearable healthcare devices,assistive technology,and intelligent soft robotics.Moreover,it possesses the advantages of high sensitivity and fast response time in practical applications.
基金supported by the National Natural Science Foundation of China(51973166,52373097)Beijing Natural Science Foundation(2232064)。
文摘Pressure sensors are essential for a wide range of applica-tions,including health monitoring,industrial diagnostics,etc.However,achieving both high sensitivity and mechanical ability to withstand high pressure in a single material remains a significant challenge.This study introduces a high-performance cellulose hydrogel inspired by the biomi-metic layered porous structure of human skin.The hydrogel features a novel design composed of a soft layer with large macropores and a hard layer with small micropores,each of which contribute uniquely to its pressure-sensing capabilities.The macropores in the soft part facilitate significant deforma-tion and charge accumulation,providing exceptional sensitivity to low pressures.In contrast,the microporous structure in the hard part enhances pressure range,ensuring support under high pressures and preventing structural failure.The performance of hydrogel is further optimized through ion introduction,which improves its conductivity,and as well the sensitivity.The sensor demonstrated a high sensitivity of 1622kPa^(-1),a detec-tion range up to 160 kPa,excellent conductivity of 4.01 Sm^(-1),rapid response time of 33 ms,and a low detection limit of 1.6 Pa,outperforming most existing cellulose-based sensors.This innovative hierarchically porous architecture not only enhances the pressure-sensing performance but also offers a simple and effective approach for utilizing natural polymers in sensing technologies.The cellulose hydrogel demonstrates sig-nificant potential in both health monitoring and industrial applications,providing a sensitive,durable,and versatile solution for pressure sensing.
基金supported by the Youth Project of the National Natural Science Foundation of China(Grant No.52105594)the Youth Project of the Applied Basic Research Program of Shanxi Province(Grant No.20210302124274)+4 种基金the Key Research and Development Program of Shanxi Province(Grant No.202102030201005)the Natural Youth Science Foundation of Shanxi Province(Grant Nos.202103021223005 and 202203021212015)the Fund for Shanxi 1331 Project,the Science and Technology Innovation Plan for Colleges and Universities in Shanxi Province(Grant No.2022L575)the Science and Technology Innovation Project in Higher Schools in Shanxi(Grant No.J2020383)Teaching Reform and Innovation Project of the Education Department of Shanxi Province(Grant No.J20221195).
文摘Flexible pressure sensors show great promise for applications in such fields as electronic skin,healthcare,and intelligent robotics.Traditional capacitive pressure sensors,however,face the problem of low sensitivity,which limits their wider application.In this paper,a flexible capacitive pressure sensor with microstructured ionization layer is fabricated by a sandwich-type process,with a low-cost and simple process of inverted molding with sandpapers being used to form a thermoplastic polyurethane elastomer ionic film with double-sided microstructure as the dielectric layer of the sensor,with silver nanowires as electrodes.The operating mechanism of this iontronic pressure sensor is analyzed using a graphical method,and the sensor is tested on a pressure platform.The test results show that the sensor has ultrahigh pressure sensitivities of 3.744 and 1.689 kPa^(−1) at low(0-20 kPa)and high(20-800 kPa)pressures,respectively,as well as a rapid response time(100 ms),and it exhibits good stability and repeatability.The sensor can be used for sensitive monitoring of activities such as finger bending,and for facial expression(smile,frown)recognition,as well as speech recognition.
基金supported by the National Natural Science Foundation of China(NSFC)(62422501)Beijing Nova Program(20230484254,20240484742)Hebei Natural Science Foundation(F2024105039).
文摘Implantable temperature sensors are revolutionizing physiological monitoring and playing a crucial role in diagnostics,therapeutics,and life sciences research.This review classifies the materials used in these sensors into three categories:metal-based,inorganic semiconductor,and organic semiconductor materials.Metal-based materials are widely used in medical and industrial applications due to their linearity,stability,and reliability.Inorganic semiconductors provide rapid response times and high miniaturization potential,making them promising for biomedical and environmental monitoring.Organic semiconductors offer high sensitivity and ease of processing,enabling the development of flexible and stretchable sensors.This review analyzes recent studies for each material type,covering design principles,performance characteristics,and applications,highlighting key advantages and challenges regarding miniaturization,sensitivity,response time,and biocompatibility.Furthermore,critical performance parameters of implantable temperature sensors based on different material types are summarized,providing valuable references for future sensor design and optimization.The future development of implantable temperature sensors is discussed,focusing on improving biocompatibility,long-term stability,and multifunctional integration.These advancements are expected to expand the application potential of implantable sensors in telemedicine and dynamic physiological monitoring.
基金financially supported by the National Natural Science Foundation of China(No.62205091)the Fundamental Research Foundation for Universities of Heilongjiang Province(No.2022-KYYWF-0121)+1 种基金the Natural Science Foundation of Heilongjiang Province Project(No.LH2022F028)the National Key Research and Development Program of China(No.2023YFF1206100)。
文摘The emergence of two-dimensional nanomaterials,especially MXene,significantly overcomes the limitations of flexible pressure sensors regarding their sensing abilities,mechanical properties,and electromagnetic shielding effectiveness.This advancement underscores their great potential for use in wearable and medical monitoring devices.However,single-layer MXene is highly prone to oxidation when exposed to air and tends to stack between layers.Combining MXene with other functional materials to create heterojunction structures effectively addresses the stacking problem while also providing the resulting composites with excellent electrical conductivity,mechanical flexibility,and electromagnetic shielding capabilities,which are essential for enhancing sensor performance.This review systematically outlines various microstructural designs and improvement strategies aimed at boosting the sensing efficiency of different flexible pressure sensors based on MXene.It offers a comprehensive analysis of their significance in medical monitoring,anticipates future challenges and opportunities,and serves as an important reference for advancing precision and personalized approaches in medical monitoring.
基金the National Natural Science Foundation of China(52175517,51720105016,and 52405599)the China National Postdoctoral Program for Innovative Talents(BX20230289)+2 种基金the China Postdoctoral Science Foundation(2024M752567)the Recruitment Program of Global Experts(WQ2017610445)the Innovation Capability Support Program of Shaanxi Province(2021TD-23).
文摘Microelectromechanical system(MEMS)high-temperature pressure sensors are widely used in aerospace,petrochemical industries,automotive electronics,and other fields owing to their advantages of miniaturization,lightweight design,simplified signal processing,and high accuracy.In recent years,advances in semiconductor material growth technology and intelligent equipment operation have significantly increased interest in high-temperature pressure sensors based on the third-generation semiconductor silicon carbide(SiC).This review examines the material properties of SiC single crystals and discusses several technologies influencing the performance of SiC pressure sensors,including the piezoresistive effect,ohmic contact,etching processes,and packaging methodologies.Additionally,it explores future research directions in the field.The review highlights the importance of increasing operating temperatures and advancing sensor integration as critical trends for future SiC high-temperature pressure sensor research and applications.
基金the financial support from the National Natural Science Foundation of China(52475610,52105593)the Zhejiang Provincial Natural Science Foundation of China(LDQ24E050001)+1 种基金the"Pioneer"and"Leading Goose"R&D Program of Zhejiang(2023C03007,2024C01173)the Fundamental Research Funds for the Central Universities(226-2024-00085)。
文摘Extreme environments challenge the structural health monitoring of advanced equipment.In-situ dynamic tracking temperature is of particular value due to its enormous impact on material properties.However,the realization of such integrated temperature sensors typically requires complicated layer-by-layer molding and sintering processes including additional thermal barrier coatings.Herein,we report a laser-induced in-situ conductive passivation strategy for the fabrication of a thin-film based wide-range temperature sensor.The instantaneous thermal effect of laser irradiation creates crystalline conductive traces in response to temperature variations.Synchronously,it also allows the formation of an amorphous antioxidative layer without necessitating extra protective coatings.Such configuration enables precise real-time sensing across-50℃to 950℃following the Steinhart-Hart equation.It also exhibits durable performance with only 1.2%drift over 20 hours during long-term high-temperature,instant thermal shock,frequent wearing,and severe vibration.This in-situ,facile laser manufacturing strategy holds great promise in structural health monitoring and fault diagnosis for advanced equipment working in extreme environments.
文摘Multimodal information sensing becomes increasingly critical under the rapid development of automation and information technology.With the ability to provide high-density and high-sensitivity pressure detection,pressure sensor arrays have been applied to a variety of fields,including intelligent robotics,medical monitoring,and industrial automation.This study proposes a pressure sensor array system based on the Minecraft game platform.The simulation and testing of the pressure sensor arrays system have been conducted using redstone circuits and pressure plates in Minecraft to simulate real-world piezoelectric pressure sensor arrays.A series of experiments verified the feasibility and effectiveness of the system.
基金supported by the Natural Science Foundation of Hunan Province,China(No.2024JJ6039).
文摘Laser-Induced Graphene (LIG) is regarded as a promising sensor carrier due to its inherent three-dimensional porous structure. However, as two mutually exclusive properties of the pressure sensor, sensitivity and working range are difficult to be further improved by the single porous structure. Inspired by the unique geometry of Oxalis corniculata L. leaves, we here propose a novel method consist of laser pre-etching and inducing steps to fabricate LIG-based electrodes with a two-stage architecture featuring microjigsaw and microporous structures. The following injection of liquid-silicone significantly improves the friction resistance and bending reliability of LIG materials. The interface contact between external microjigsaw structures induces substantial resistance changes, and the internal microporous structure exhibits reversibility during dynamic deformation. Consequently, the jigsaw-like pressure sensor achieves a balanced performance with sensitivities of 3.64, 1.20 and 0.03 kPa^(- 1) in pressure range of 0 -20, 20 - 40 and 40 - 150 kPa, respectively. The bionic LIG-based pressure sensor serves as the core component and further integrated with an all-in-one wireless transmission system capable of monitoring various health parameters such as subtle pulse rates, heartbeat rhythms, sounds, etc., indicating broad prospects in future wearable electronics.
基金support from Beijing Natural Science Foundation−Xiaomi Innovation Joint Fund(Grant No.L233009)the National Natural Science Foundation of China(NSFC Grant Nos.62422409,62174152 and 62374159)from the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2020115).
文摘High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneously achieve high sensitivity,a wide detection range,and good mechanical stability remains a challenge.In this paper,we propose a flexible piezoresistive pressure sensor based on a Ti_(3)C_(2)Tx(MXene)/polyethylene oxide(PEO)composite nanofiber membrane(CNM).The sensor,utilizing MXene(0.4 wt%)/PEO(5 wt%),exhibits high sensitivity(44.34 kPa^(−1)at 0−50 kPa,12.99 kPa^(−1)at 50−500 kPa)and can reliably monitor physiological signals and other subtle cues.Moreover,the sensor features a wide detection range(0−500 kPa),fast response and recovery time(~150/45 ms),and excellent mechanical stability(over 10000 pressure cycles at maximum load).Through an MXene/PEO sensor array,we demonstrate its applications in human physiological signal monitoring,providing a reliable way to expand the application of MXene-based flexible pressure sensors.
基金supported by the National Nature Science Foundation of China(No.62122030,62333008,62371205,52103208)National Key Research and Development Program of China(No.2021YFB3201300)+1 种基金Application and Basic Research of Jilin Province(20130102010 JC)Fundamental Research Funds for the Central Universities,Jilin Provincial Science and Technology Development Program(20230101072JC)。
文摘Wearable pressure sensors capable of adhering comfortably to the skin hold great promise in sound detection.However,current intelligent speech assistants based on pressure sensors can only recognize standard languages,which hampers effective communication for non-standard language people.Here,we prepare an ultralight Ti_(3)C_(2)T_(x)MXene/chitosan/polyvinylidene difluoride composite aerogel with a detection range of 6.25 Pa-1200 k Pa,rapid response/recovery time,and low hysteresis(13.69%).The wearable aerogel pressure sensor can detect speech information through the throat muscle vibrations without any interference,allowing for accurate recognition of six dialects(96.2%accuracy)and seven different words(96.6%accuracy)with the assistance of convolutional neural networks.This work represents a significant step forward in silent speech recognition for human–machine interaction and physiological signal monitoring.
基金supported by the Scientific Research Program Funded by Shaanxi Provincial Education Department (No.15JK1573)the Postgraduate Innovation and Practice Ability Development Fund of Xi’an Shiyou University (No.YCS21211084)。
文摘We proposed a fiber optic high temperature sensor based on the Mach-Zehnder interference(MZI)structure,which is composed of two lengths of multi-mode fibers(MMFs),a length of few-mode fiber(FMF)and two sections of single-mode fibers(SMFs).Firstly,the two sections of MMFs were spliced with two sections of SMFs.Then,the MMFs were fused to two ends of FMF to form a symmetrically structured fiber-optic MZI structure.In this structure,the MMF served as the optical mode field coupling element,and the cladding and core of the FMF are the interference arm and the reference arm of the MZI structure,respectively.We investigated the sensor's response characteristics of the temperature and strain.The experimental results indicate that the sensor is sensitive to temperature variation,and the temperature response sensitivity is up to 61.4 pm/℃ in the range of 40-250℃,while the sensor has weak strain sensitivity,its strain sensitivity is only-0.72 pm/μe in the strain range of 0-1400μe.Moreover,the sensor has good stability and repeatability.In brief,the proposed fiber optic high temperature sensor has good properties,such as high sensitivity,compact structure,good stability and repeatability,which can be used for monitoring the temperature of submerged oil electric pump units under oil wells.
基金support by the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai(AMGM2021A03)the"Special Lubrication and Sealing for Aerospace"Shaanxi Provincial Science and Technology Innovation Team(2024RS-CXTD-63)+1 种基金the Xianyang2023 Key Research and Development Plan(L2023-ZDYF-QYCX-009)the World First Class University and First Class Academic Discipline Construction Funding 2023(0604024GH0201332,0604024SH0201332).
文摘Flexible and wearable pressure sensors hold immense promise for health monitoring,covering disease detection and postoperative rehabilitation.Developing pressure sensors with high sensitivity,wide detection range,and cost-effectiveness is paramount.By leveraging paper for its sustainability,biocompatibility,and inherent porous structure,herein,a solution-processed all-paper resistive pressure sensor is designed with outstanding performance.A ternary composite paste,comprising a compressible 3D carbon skeleton,conductive polymer poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate),and cohesive carbon nanotubes,is blade-coated on paper and naturally dried to form the porous composite electrode with hierachical micro-and nano-structured surface.Combined with screen-printed Cu electrodes in submillimeter finger widths on rough paper,this creates a multiscale hierarchical contact interface between electrodes,significantly enhancing sensitivity(1014 kPa-1)and expanding the detection range(up to 300 kPa)of as-resulted all-paper pressure sensor with low detection limit and power consumption.Its versatility ranges from subtle wrist pulses,robust finger taps,to large-area spatial force detection,highlighting its intricate submillimetermicrometer-nanometer hierarchical interface and nanometer porosity in the composite electrode.Ultimately,this all-paper resistive pressure sensor,with its superior sensing capabilities,large-scale fabrication potential,and cost-effectiveness,paves the way for next-generation wearable electronics,ushering in an era of advanced,sustainable technological solutions.
基金The authors acknowledge the financial support from the National Natural Science Foundation of China(Nos.52071280 and 51972280)the Natural Science Foundation of Hebei Province,China(Nos.E2020203151 and E2022203208)+1 种基金the Research Program of the College Science&Technology of Hebei Province,China(No.ZD2020121)the Cultivation Project for Basic Research and Innovation of Yanshan University,China(No.2021LGZD016).
文摘Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibers/polypyrrole/nickel(APN)aerogels,which serve dual roles as both microwave absorbers and pressure sensors.In this work,we focused on the preparation of aramid nanofibers/polypyrrole(AP15)aerogels,where the mass ratio of aramid nanofibers to pyrrole was 1:5.We employed the oxidative polymerization method for the preparation process.Following this,nickel was thermally evaporated onto the surface of the AP15 aerogels,resulting in the creation of an ultralight(9.35 mg·cm^(-3)).This aerogel exhibited a porous structure.The introduction of nickel into the aerogel aimed to enhance magnetic loss and adjust impedance matching,thereby improving electromagnetic wave absorption performance.The minimum reflection loss value achieved was-48.7 dB,and the maximum effective absorption bandwidth spanned 8.42 GHz with a thickness of 2.9 mm.These impressive metrics can be attributed to the three-dimensional network porous structure of the aerogel and perfect impedance matching.Moreover,the use of aramid nanofibers and a three-dimensional hole structure endowed the APN aerogels with good insulation,flame-retardant properties,and compression resilience.Even under a compression strain of 50%,the aerogel maintained its resilience over 500 cycles.The incorporation of polypyrrole and nickel particles further enhanced the conductivity of the aerogel.Consequently,the final APN aerogel sensor demonstrated high sensitivity(10.78 kPa-1)and thermal stability.In conclusion,the APN aerogels hold significant promise as ultra-broadband microwave absorbers and pressure sensors.
