High-temperature thin-film thermocouples(TFTCs)have attracted significant attention in the aerospace and steel metallurgy industry.However,previous studies on TFTCs have primarily focused on the two-dimensional planar...High-temperature thin-film thermocouples(TFTCs)have attracted significant attention in the aerospace and steel metallurgy industry.However,previous studies on TFTCs have primarily focused on the two-dimensional planar-type,whose thermal sensitive area has to be perpendicular to the test environment,and therefore affects the thermal fluids pattern or loses accuracy.In order to address this problem,recent studies have developed three-dimensional probe-type TFTCs,which can be set parallel to the test environment.Nevertheless,the probe-type TFTCs are limited by their measurement threshold and poor stability at high temperatures.To address these issues,in this study,we propose a novel probe-type TFTC with a sandwich structure.The sensitive layer is compounded with indium oxide doped zinc oxide and fabricated using screen-printing technology.With the protection of sandwich structure on electrode film,the sensor demonstrates robust high-temperature stability,enabling continuous working at 1200℃ above 5 h with a low drift rate of 2.3℃·h^(−1).This sensor exhibits a high repeatability of 99.3% when measuring a wide range of temperatures,which is beyond the most existing probe-type TFTCs reported in the literature.With its excellent high-temperature performance,this temperature sensor holds immense potentials for enhancing equipment safety in the aerospace engineering and ensuring product quality in the steel metallurgy industry.展开更多
Flexible temperature sensors have been extensively investigated due to their prospect of wide application in various flexible electronic products.However,most of the current flexible temperature sensors only work well...Flexible temperature sensors have been extensively investigated due to their prospect of wide application in various flexible electronic products.However,most of the current flexible temperature sensors only work well in a narrow temperature range,with their application at high or low temperatures still being a big challenge.This work proposes a flexible thermocouple temperature sensor based on aerogel blanket substrate,the temperature-sensitive layer of which uses the screen-printing technology to prepare indium oxide and indium tin oxide.It has good temperature sensitivity,with the test sensitivity reaching 226.7μV℃^(−1).Most importantly,it can work in a wide temperature range,from extremely low temperatures down to liquid nitrogen temperature to high temperatures up to 1200℃,which is difficult to be achieved by other existing flexible temperature sensors.This temperature sensor has huge application potential in biomedicine,aerospace and other fields.展开更多
Due to the excellent mechanical,chemical,and electrical properties of third-generation semiconductor silicon carbide(SiC),pressure sensors utilizing this material might be able to operate in extreme environments with ...Due to the excellent mechanical,chemical,and electrical properties of third-generation semiconductor silicon carbide(SiC),pressure sensors utilizing this material might be able to operate in extreme environments with temperatures exceeding 300℃.However,the significant output drift at elevated temperatures challenges the precision and stability of measurements.Real-time in situ temperature monitoring of the pressure sensor chip is highly important for the accurate compensation of the pressure sensor.In this study,we fabricate platinum(Pt)thin-film resistance temperature detectors(RTDs)on a SiC substrate by incorporating aluminum oxide(Al_(2)O_(3))as the transition layer and utilizing aluminum nitride(AIN)grooves for alignment through microfabrication techniques.The composite layers strongly adhere to the substrate at temperatures reaching 950℃,and the interface of the Al2O3/Pt bilayer remains stable at elevated temperatures of approximately 950 C.This stability contributes to the excellent high-temperature electrical performance of the Pt RTD,enabling it to endure temperatures exceeding 850℃ with good linearity.These characteristics establish a basis for the future integration of Pt RTD in SiC pressure sensors.Furthermore,tests and analyses are conducted on the interfacial diffusion,surface morphological,microstructural,and electrical properties of the Pt flms at various annealing temperatures.It can be inferred that the tensile stress and self-diffusion of Pt films lead to the formation of hillocks,ultimately reducing the electrical performance of the Pt thin-flm RTD.To increase the upper temperature threshold,steps should be taken to prevent the agglomeration of Pt films.展开更多
Microelectromechanical system(MEMS)pressure sensors based on silicon are widely used and offer the benefits of miniaturization and high precision.However,they cannot easily withstand high temperatures exceeding 150 ℃...Microelectromechanical system(MEMS)pressure sensors based on silicon are widely used and offer the benefits of miniaturization and high precision.However,they cannot easily withstand high temperatures exceeding 150 ℃ because of intrinsic material limits.Herein,we proposed and executed a systematic and full-process study of Sic-based MEMS pressure sensors that operate stably from-50 to 300 ℃.First,to explore the nonlinear piezoresistive effect,the temperature coefficient of resistance(TCR)values of 4H-SiC piezoresistors were obtained from-50 to 500 ℃.A conductivity variation model based on scattering theory was established to reveal the nonlinear variation mechanism.Then,a piezoresistive pressure sensor based on 4H-SiC was designed and fabricated.The sensor shows good output sensitivity(3.38 mVN/MPa),accuracy(0.56%FS)and low temperature coefficient of sensitivity(TCS)(-0.067%FS/℃)in the range of-50 to 300 ℃.In addition,the survivability of the sensor chip in extreme environments was demonstrated by its anti-corrosion capability in H_(2)SO_(4) and NaOH solutions and its radiation tolerance under 5 W X-rays.Accordingly,the sensor developed in this work has high potential to measure pressure in high-temperature and extreme environments such as are faced in geothermal energy extraction,deep well dilling,aeroengines and gas turbines.展开更多
For the large amount of waste heat wasted in daily life and industrial production,we propose a new type of flexible thermoelectric generators(F-TEGs)which can be used as a large area bionic skin to achieve energy harv...For the large amount of waste heat wasted in daily life and industrial production,we propose a new type of flexible thermoelectric generators(F-TEGs)which can be used as a large area bionic skin to achieve energy harvesting of thermal energy.With reference to biological structures such as pinecone,succulent,and feathers,we have designed and fabricated a biomimetic flexible TEG that can be applied in a wide temperature range which has the highest temperature energy harvesting capability currently.The laminated free structure of the bionic F-TEG dramatically increases the efficiency and density of energy harvesting.The F-TEGs(single TEG only 101.2 mg in weight),without an additional heat sink,demonstrates the highest output voltage density of 286.1 mV/cm^(2)and the maximum power density is 66.5 mW/m^(2) at a temperature difference of nearly 1000℃.The flexible characteristics of F-TEGs make it possible to collect the diffused thermal energy by flexible attachment to the outer walls of high-temperature pipes and vessels of different diameters and shapes.This work shows a new design and application concept for flexible thermal energy collectors,which fills the gap of flexible energy harvesting in high-temperature environment.展开更多
Accurate temperature measurements can efficiently solve numerous critical problems and provide key information.Herein,a flexible micro-three-dimensional sensor,with a combination of platinum and indium oxide to form t...Accurate temperature measurements can efficiently solve numerous critical problems and provide key information.Herein,a flexible micro-three-dimensional sensor,with a combination of platinum and indium oxide to form thermocouples,is designed and fabricated by a microfabrication process to achieve in situ real-time temperature measurements.The stability and reliability of the sensor are greatly improved by optimizing the process parameters,structural design,and preparation methods.A novel micro-three-dimensional structure with better malleability is designed,which also takes advantage of the fast response of a two-dimensional thin film.The as-obtained flexible temperature sensor with excellent stability and reliability is expected to greatly contribute to the development of essential components in various emerging research fields,including bio-robot and healthcare systems.The model of the application sensor in a mask is further proposed and designed to realize the collection of health information,reducing the number of deaths caused by the lack of timely detection and treatment of patients.展开更多
Flexible strain sensors are promising candidates for intelligent wearable devices.Among previous studies,although crack-based sensors have attracted a lot of attention due to their ultrahigh sensitivity,large strain u...Flexible strain sensors are promising candidates for intelligent wearable devices.Among previous studies,although crack-based sensors have attracted a lot of attention due to their ultrahigh sensitivity,large strain usually causes fractures in the conductive paths.Because of the unstable crack structure,the tradeoff between sensitivity and workable strain range is still a challenge.As carbon nanotubes(CNTs)and silver nanowires(AgNWs)can form a strong interface with the thermoplastic substrate and strengthen the conductive network by capillary force during water evaporation,CNTs and AgNWs were deposited on electrospun TPU fiber mats via vacuum-assisted filtration in this work.The prestretching treatment constructed a microcrack structure that endowed the sensor with the combined characteristics of a wide working range(0~171%strain),ultrahigh sensitivity(a gauge factor of 691 within 0~102%strain,~2×10^(4) within 102~135%strain,and>11×10^(4) within 135~171%strain),a fast response time(~65 ms),small hysteresis,and superior durability(>2000 cycles).Subsequently,the sensing mechanism of the sensor was studied.Distributed microcrack propagation based on the“island-bridge”structure was explained in detail,and its influence on the strain-sensing behavior of the sensor was analyzed.Finally,the sensor was assembled to monitor various vibration signals and human motions,demonstrating its potential applications in the fields of electronic skin and human health monitoring.展开更多
Flexible sensors used to detect NO_(2) gas generally have problems such as poor repeatability,high operating temperature,poor selectivity,and small detection range.In this work,a new spraying platform with a simple st...Flexible sensors used to detect NO_(2) gas generally have problems such as poor repeatability,high operating temperature,poor selectivity,and small detection range.In this work,a new spraying platform with a simple structure,low cost,and good film-forming consistency was designed and built to make a sensitive film(rGO/SnO_(2))for NO_(2) gas sensors.The relationship between the solid content of rGO and SnO_(2)nanoparticles,annealing temperature,and sensor performance was studied.The results show that the interdigital electrode-sensitive film formed by spraying 0.25 ml of a 0.4 wt%rGO/SnO_(2)mixture and annealing at 250℃exhibited the best comprehensive performance for NO_(2) detection.The sensor's response value for 100 ppm NO_(2) gas was 0.2640 at room temperature(25℃),and the response time and recovery time were 412.4 s and 587.3 s,respectively.In the range of 20-100 ppm,the relationship between the response and NO_(2) concentration was linear,and the correlation coefficient was 0.9851.In addition,a soft-monitoring node module with an overlimit warning function for NO_(2) gas was designed and manufactured based on flexible electronics.Finally,the flexible sensor and node module were embedded into woven fabric that could be used to make a mask or a watch that could detect NO_(2) gas,realizing the practical application of flexible NO_(2) gas sensors in the field of wearable electronics.展开更多
Capacitive sensors are efficient tools for biophysical force measurement,which is essential for the exploration of cellular behavior.However,attention has been rarely given on the influences of external mechanical and...Capacitive sensors are efficient tools for biophysical force measurement,which is essential for the exploration of cellular behavior.However,attention has been rarely given on the influences of external mechanical and internal electrical interferences on capacitive sensors.In this work,a bionic swallow structure design norm was developed for mechanical decoupling,and the influences of structural parameters on mechanical behavior were fully analyzed and optimized.A bionic feather comb distribution strategy and a portable readout circuit were proposed for eliminating electrostatic interferences.Electrostatic instability was evaluated,and electrostatic decoupling performance was verified on the basis of a novel measurement method utilizing four complementary comb arrays and applicationspecific integrated circuit readouts.An electrostatic pulling experiment showed that the bionic swallow structure hardly moved by 0.770 nm,and the measurement error was less than 0.009% for the area-variant sensor and 1.118% for the gap-variant sensor,which can be easily compensated in readouts.The proposed sensor also exhibited high resistance against electrostatic rotation,and the resulting measurement error dropped below 0.751%.The rotation interferences were less than 0.330 nm and(1.829×10^(-7))°,which were 35 times smaller than those of the traditional differential one.Based on the proposed bionic decoupling method,the fabricated sensor exhibited overwhelming capacitive sensitivity values of 7.078 and 1.473 pF/μm for gap-variant and area-variant devices,respectively,which were the highest among the current devices.High immunity to mechanical disturbances was maintained simultaneously,i.e.,less than 0.369% and 0.058% of the sensor outputs for the gap-variant and area-variant devices,respectively,indicating its great performance improvements over existing devices and feasibility in ultralow biomedical force measurement.展开更多
With the growing demand for thermal management of electronic devices,cooling of high-precision instruments,and biological cryopreservation,heat flux measurement of complex surfaces and at ultralow temperatures has bec...With the growing demand for thermal management of electronic devices,cooling of high-precision instruments,and biological cryopreservation,heat flux measurement of complex surfaces and at ultralow temperatures has become highly imperative.However,current heat flux sensors(HFSs)are commonly used in high-temperature scenarios and have problems when applied in low-temperature conditions,such as low sensitivity and embrittlement.In this study,we developed a flexible and highly sensitive HFS that can operate at ultralow to high temperatures,ranging from−196°C to 273°C.The sensitivities of HFSs with thicknesses of 0.2 mm and 0.3 mm,which are efficiently manufactured by the screen-printing method,reach 11.21μV/(W/m2)and 13.43μV/(W/m2),respectively.The experimental results show that there is a less than 3%resistance change from bending to stretching.Additionally,the HFS can measure heat flux in both exothermic and absorptive cases and can measure heat flux up to 25 kW/m2.Additionally,we demonstrate the application of the HFS to the measurement of minuscule heat flux,such as heat dissipation of human skin and cold water.This technology is expected to be used in heat flux measurements at ultralow temperatures or on complex surfaces,which has great importance in the superconductor and cryobiology field.展开更多
基金supports from the National Key Research and Development Program of China(2022YFB3207502).
文摘High-temperature thin-film thermocouples(TFTCs)have attracted significant attention in the aerospace and steel metallurgy industry.However,previous studies on TFTCs have primarily focused on the two-dimensional planar-type,whose thermal sensitive area has to be perpendicular to the test environment,and therefore affects the thermal fluids pattern or loses accuracy.In order to address this problem,recent studies have developed three-dimensional probe-type TFTCs,which can be set parallel to the test environment.Nevertheless,the probe-type TFTCs are limited by their measurement threshold and poor stability at high temperatures.To address these issues,in this study,we propose a novel probe-type TFTC with a sandwich structure.The sensitive layer is compounded with indium oxide doped zinc oxide and fabricated using screen-printing technology.With the protection of sandwich structure on electrode film,the sensor demonstrates robust high-temperature stability,enabling continuous working at 1200℃ above 5 h with a low drift rate of 2.3℃·h^(−1).This sensor exhibits a high repeatability of 99.3% when measuring a wide range of temperatures,which is beyond the most existing probe-type TFTCs reported in the literature.With its excellent high-temperature performance,this temperature sensor holds immense potentials for enhancing equipment safety in the aerospace engineering and ensuring product quality in the steel metallurgy industry.
基金supported by The National Key Research and Development Program of China(2020YFB2009100)Natural Science Basic Research Program of Shaanxi(Program No.2022JQ-508)National Science and Technology Major Project(Grant No.J2019-V-0006-0100),Open research fund of SKLMS(Grant No.sklms2021009).
文摘Flexible temperature sensors have been extensively investigated due to their prospect of wide application in various flexible electronic products.However,most of the current flexible temperature sensors only work well in a narrow temperature range,with their application at high or low temperatures still being a big challenge.This work proposes a flexible thermocouple temperature sensor based on aerogel blanket substrate,the temperature-sensitive layer of which uses the screen-printing technology to prepare indium oxide and indium tin oxide.It has good temperature sensitivity,with the test sensitivity reaching 226.7μV℃^(−1).Most importantly,it can work in a wide temperature range,from extremely low temperatures down to liquid nitrogen temperature to high temperatures up to 1200℃,which is difficult to be achieved by other existing flexible temperature sensors.This temperature sensor has huge application potential in biomedicine,aerospace and other fields.
基金The authors are thankful for support from the National Natural Science Foundation of China(Nos.52175517 and 51720105016)the Zhejiang Laboratory(2022MGOAB03)+3 种基金the China Postdoctoral Science Foundation(No.2017M610634)the Recruitment Program of Global Experts(Grant No.WQ2017610445)the Innovation Capability Support Program of Shaanxi Province(No.2021TD-23)the China National Postdoctoral Program for Innovative Talents(BX20230289)。
文摘Due to the excellent mechanical,chemical,and electrical properties of third-generation semiconductor silicon carbide(SiC),pressure sensors utilizing this material might be able to operate in extreme environments with temperatures exceeding 300℃.However,the significant output drift at elevated temperatures challenges the precision and stability of measurements.Real-time in situ temperature monitoring of the pressure sensor chip is highly important for the accurate compensation of the pressure sensor.In this study,we fabricate platinum(Pt)thin-film resistance temperature detectors(RTDs)on a SiC substrate by incorporating aluminum oxide(Al_(2)O_(3))as the transition layer and utilizing aluminum nitride(AIN)grooves for alignment through microfabrication techniques.The composite layers strongly adhere to the substrate at temperatures reaching 950℃,and the interface of the Al2O3/Pt bilayer remains stable at elevated temperatures of approximately 950 C.This stability contributes to the excellent high-temperature electrical performance of the Pt RTD,enabling it to endure temperatures exceeding 850℃ with good linearity.These characteristics establish a basis for the future integration of Pt RTD in SiC pressure sensors.Furthermore,tests and analyses are conducted on the interfacial diffusion,surface morphological,microstructural,and electrical properties of the Pt flms at various annealing temperatures.It can be inferred that the tensile stress and self-diffusion of Pt films lead to the formation of hillocks,ultimately reducing the electrical performance of the Pt thin-flm RTD.To increase the upper temperature threshold,steps should be taken to prevent the agglomeration of Pt films.
基金support from National Natural Science Foundation of China(No.52175517,51720105016)Zhejiang Lab(2022MG0AB03)+2 种基金China Postdoctoral Science Foundation(No.2017M610634)The Recruitment Program of Global Experts(Grant No.WQ2017610445)Innovation Capability Support Program of Shaanxi Province(No.2021TD-23).
文摘Microelectromechanical system(MEMS)pressure sensors based on silicon are widely used and offer the benefits of miniaturization and high precision.However,they cannot easily withstand high temperatures exceeding 150 ℃ because of intrinsic material limits.Herein,we proposed and executed a systematic and full-process study of Sic-based MEMS pressure sensors that operate stably from-50 to 300 ℃.First,to explore the nonlinear piezoresistive effect,the temperature coefficient of resistance(TCR)values of 4H-SiC piezoresistors were obtained from-50 to 500 ℃.A conductivity variation model based on scattering theory was established to reveal the nonlinear variation mechanism.Then,a piezoresistive pressure sensor based on 4H-SiC was designed and fabricated.The sensor shows good output sensitivity(3.38 mVN/MPa),accuracy(0.56%FS)and low temperature coefficient of sensitivity(TCS)(-0.067%FS/℃)in the range of-50 to 300 ℃.In addition,the survivability of the sensor chip in extreme environments was demonstrated by its anti-corrosion capability in H_(2)SO_(4) and NaOH solutions and its radiation tolerance under 5 W X-rays.Accordingly,the sensor developed in this work has high potential to measure pressure in high-temperature and extreme environments such as are faced in geothermal energy extraction,deep well dilling,aeroengines and gas turbines.
基金This work was supported by the National Key Research and Development Program of China(No.2020YFB2009100)the Natural Science Basic Research Program of Shaanxi(No.2022JQ-508)+2 种基金the National Science and Technology Major Project(No.J2019-V-0006-0100)the Open research fund of SKLMS(No.sklms2021009)Zhaojun Liu received the China Scholarship Council Fund(No.202206280155)for his research stay at National University of Singapore.
文摘For the large amount of waste heat wasted in daily life and industrial production,we propose a new type of flexible thermoelectric generators(F-TEGs)which can be used as a large area bionic skin to achieve energy harvesting of thermal energy.With reference to biological structures such as pinecone,succulent,and feathers,we have designed and fabricated a biomimetic flexible TEG that can be applied in a wide temperature range which has the highest temperature energy harvesting capability currently.The laminated free structure of the bionic F-TEG dramatically increases the efficiency and density of energy harvesting.The F-TEGs(single TEG only 101.2 mg in weight),without an additional heat sink,demonstrates the highest output voltage density of 286.1 mV/cm^(2)and the maximum power density is 66.5 mW/m^(2) at a temperature difference of nearly 1000℃.The flexible characteristics of F-TEGs make it possible to collect the diffused thermal energy by flexible attachment to the outer walls of high-temperature pipes and vessels of different diameters and shapes.This work shows a new design and application concept for flexible thermal energy collectors,which fills the gap of flexible energy harvesting in high-temperature environment.
基金This work is supported by the National Key Research and Development Program of China(2020YFB2009100 and 2019YFB2004501)National Natural Science Foundation of China(No.91748207)+1 种基金China Postdoctoral Science Foundation(2020M683461)111 Program(No.Bl2016).
文摘Accurate temperature measurements can efficiently solve numerous critical problems and provide key information.Herein,a flexible micro-three-dimensional sensor,with a combination of platinum and indium oxide to form thermocouples,is designed and fabricated by a microfabrication process to achieve in situ real-time temperature measurements.The stability and reliability of the sensor are greatly improved by optimizing the process parameters,structural design,and preparation methods.A novel micro-three-dimensional structure with better malleability is designed,which also takes advantage of the fast response of a two-dimensional thin film.The as-obtained flexible temperature sensor with excellent stability and reliability is expected to greatly contribute to the development of essential components in various emerging research fields,including bio-robot and healthcare systems.The model of the application sensor in a mask is further proposed and designed to realize the collection of health information,reducing the number of deaths caused by the lack of timely detection and treatment of patients.
基金the National Natural Science Foundation of China(No.52175517,51720105016)Zhejiang Lab(No.2022MG0AB03)+3 种基金China Postdoctoral Science Foundation(No.2017M610634)Shaanxi Postdoctoral Science Foundation(No.2017BSHEDZZ73)National Key Research&Development(R&D)Program of China(Grant No.2016YFB0501600)the Recruitment Program of Global Experts(Grant No.WQ2017610445)for their support.
文摘Flexible strain sensors are promising candidates for intelligent wearable devices.Among previous studies,although crack-based sensors have attracted a lot of attention due to their ultrahigh sensitivity,large strain usually causes fractures in the conductive paths.Because of the unstable crack structure,the tradeoff between sensitivity and workable strain range is still a challenge.As carbon nanotubes(CNTs)and silver nanowires(AgNWs)can form a strong interface with the thermoplastic substrate and strengthen the conductive network by capillary force during water evaporation,CNTs and AgNWs were deposited on electrospun TPU fiber mats via vacuum-assisted filtration in this work.The prestretching treatment constructed a microcrack structure that endowed the sensor with the combined characteristics of a wide working range(0~171%strain),ultrahigh sensitivity(a gauge factor of 691 within 0~102%strain,~2×10^(4) within 102~135%strain,and>11×10^(4) within 135~171%strain),a fast response time(~65 ms),small hysteresis,and superior durability(>2000 cycles).Subsequently,the sensing mechanism of the sensor was studied.Distributed microcrack propagation based on the“island-bridge”structure was explained in detail,and its influence on the strain-sensing behavior of the sensor was analyzed.Finally,the sensor was assembled to monitor various vibration signals and human motions,demonstrating its potential applications in the fields of electronic skin and human health monitoring.
基金funded by the Natural Science Foundation of China(51805421,91748207,51805426,and 51720105016).
文摘Flexible sensors used to detect NO_(2) gas generally have problems such as poor repeatability,high operating temperature,poor selectivity,and small detection range.In this work,a new spraying platform with a simple structure,low cost,and good film-forming consistency was designed and built to make a sensitive film(rGO/SnO_(2))for NO_(2) gas sensors.The relationship between the solid content of rGO and SnO_(2)nanoparticles,annealing temperature,and sensor performance was studied.The results show that the interdigital electrode-sensitive film formed by spraying 0.25 ml of a 0.4 wt%rGO/SnO_(2)mixture and annealing at 250℃exhibited the best comprehensive performance for NO_(2) detection.The sensor's response value for 100 ppm NO_(2) gas was 0.2640 at room temperature(25℃),and the response time and recovery time were 412.4 s and 587.3 s,respectively.In the range of 20-100 ppm,the relationship between the response and NO_(2) concentration was linear,and the correlation coefficient was 0.9851.In addition,a soft-monitoring node module with an overlimit warning function for NO_(2) gas was designed and manufactured based on flexible electronics.Finally,the flexible sensor and node module were embedded into woven fabric that could be used to make a mask or a watch that could detect NO_(2) gas,realizing the practical application of flexible NO_(2) gas sensors in the field of wearable electronics.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.52105589 and U1909221)in part by the China Postdoctoral Science Foundation(Grant No.2021M692590)+2 种基金in part by the Fundamental Research Funds for the Central Universities,China(Grant No.xzy012021009)in part by the State Key Laboratory of Robotics and Systems(HIT),China(Grant No.SKLRS2021KF17)in part by the Beijing Advanced Innovation Center for Intelligent Robots and Systems,China(Grant No.2019IRS08).
文摘Capacitive sensors are efficient tools for biophysical force measurement,which is essential for the exploration of cellular behavior.However,attention has been rarely given on the influences of external mechanical and internal electrical interferences on capacitive sensors.In this work,a bionic swallow structure design norm was developed for mechanical decoupling,and the influences of structural parameters on mechanical behavior were fully analyzed and optimized.A bionic feather comb distribution strategy and a portable readout circuit were proposed for eliminating electrostatic interferences.Electrostatic instability was evaluated,and electrostatic decoupling performance was verified on the basis of a novel measurement method utilizing four complementary comb arrays and applicationspecific integrated circuit readouts.An electrostatic pulling experiment showed that the bionic swallow structure hardly moved by 0.770 nm,and the measurement error was less than 0.009% for the area-variant sensor and 1.118% for the gap-variant sensor,which can be easily compensated in readouts.The proposed sensor also exhibited high resistance against electrostatic rotation,and the resulting measurement error dropped below 0.751%.The rotation interferences were less than 0.330 nm and(1.829×10^(-7))°,which were 35 times smaller than those of the traditional differential one.Based on the proposed bionic decoupling method,the fabricated sensor exhibited overwhelming capacitive sensitivity values of 7.078 and 1.473 pF/μm for gap-variant and area-variant devices,respectively,which were the highest among the current devices.High immunity to mechanical disturbances was maintained simultaneously,i.e.,less than 0.369% and 0.058% of the sensor outputs for the gap-variant and area-variant devices,respectively,indicating its great performance improvements over existing devices and feasibility in ultralow biomedical force measurement.
基金supported by The National Key Research and Development Program of China(2022YFB3206400)the Fundamental Research Funds for the Central Universities(No.xhj032021016-06)+1 种基金the National Science and Technology Major Project(Grant No.J2022-V-0003-0029)the Open Research Fund of SKLMS(Grant No.sklms2021009).
文摘With the growing demand for thermal management of electronic devices,cooling of high-precision instruments,and biological cryopreservation,heat flux measurement of complex surfaces and at ultralow temperatures has become highly imperative.However,current heat flux sensors(HFSs)are commonly used in high-temperature scenarios and have problems when applied in low-temperature conditions,such as low sensitivity and embrittlement.In this study,we developed a flexible and highly sensitive HFS that can operate at ultralow to high temperatures,ranging from−196°C to 273°C.The sensitivities of HFSs with thicknesses of 0.2 mm and 0.3 mm,which are efficiently manufactured by the screen-printing method,reach 11.21μV/(W/m2)and 13.43μV/(W/m2),respectively.The experimental results show that there is a less than 3%resistance change from bending to stretching.Additionally,the HFS can measure heat flux in both exothermic and absorptive cases and can measure heat flux up to 25 kW/m2.Additionally,we demonstrate the application of the HFS to the measurement of minuscule heat flux,such as heat dissipation of human skin and cold water.This technology is expected to be used in heat flux measurements at ultralow temperatures or on complex surfaces,which has great importance in the superconductor and cryobiology field.
