Developing a calibration and collection system of platinum resistance temperature sensor using Python language environment can read the information returned by the serial port and automatically generate an"Temper...Developing a calibration and collection system of platinum resistance temperature sensor using Python language environment can read the information returned by the serial port and automatically generate an"Temperature Sensor Calibration Record Table"excel table with the current date as the file name.It can collect data from 10 platinum resistance temperature sensors at once,achieving automation and improving work efficiency.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
An E-type high-precision temperature sensor, which is adopted for upper air meteorology, was proposed in this paper. A computational fluid dynamics(CFD) method was implemented to analyze temperature rise induced by so...An E-type high-precision temperature sensor, which is adopted for upper air meteorology, was proposed in this paper. A computational fluid dynamics(CFD) method was implemented to analyze temperature rise induced by solar radiation at different altitudes and solar radiation intensities. A temperature rise correction equation was obtained by fitting the CFD results using a Broyden-Fletcher-Goldfarb-Shanno(BFGS) method. To verify the performance of the temperature sensor, an experimental platform was constructed. Through simulations and experiments, the relationship among the altitude, solar radiation intensity and radiation temperature rise was obtaned. The root-mean-square error(RMSE) between the temperature rise derived from the correction equation and that derived from the experiments is 0.013 K. The sample determination coefficient r2 of the solar radiation error correction equation is 0.9975.展开更多
Resonant temperature sensors have drawn considerable attention for their advantages such as high sensitivity,digitized signal output and high precision.This paper presents a new type of resonant temperature sensor,whi...Resonant temperature sensors have drawn considerable attention for their advantages such as high sensitivity,digitized signal output and high precision.This paper presents a new type of resonant temperature sensor,which uses capacitive micromachined ultrasonic transducer(CMUT)as the sensing element.A lumped electro-mechanical-thermal model was established to show its working principle for temperature measurement.The theoretical model explicitly explains the thermally induced changes in the resonant frequency of the CMUT.Then,the finite element method was used to further investigate the sensing performance.The numerical results agree well with the established analytical model qualitatively.The numerical results show that the resonant frequency varies linearly with the temperature over the range of 20℃to 140℃ at the first four vibrating modes.However,the first order vibrating mode shows a higher sensitivity than the other three higher modes.When working at the first order vibrating mode,the temperature coefficient of the resonance frequency(TCf)can reach as high as-1114.3 ppm/℃ at a bias voltage equal to 90%of the collapse voltage of the MCUT.The corresponding nonlinear error was as low as 1.18%.It is discovered that the sensing sensitivity is dependent on the applied bias voltages.A higher sensitivity can be achieved by increasing the bias voltages.展开更多
Optical fiber temperature sensors have been widely employed in enormous areas ranging from electric power industry,medical treatment,ocean dynamics to aerospace.Recently,graphene optical fiber temperature sensors attr...Optical fiber temperature sensors have been widely employed in enormous areas ranging from electric power industry,medical treatment,ocean dynamics to aerospace.Recently,graphene optical fiber temperature sensors attract tremendous attention for their merits of simple structure and direct power detecting ability.However,these sensors based on transfer techniques still have limitations in the relatively low sensitivity or distortion of the transmission characteristics,due to the unsuitable Fermi level of graphene and the destruction of fiber structure,respectively.Here,we propose a tunable and highly sensitive temperature sensor based on graphene photonic crystal fiber(Gr-PCF)with the non-destructive integration of graphene into the holes of PCF.This hybrid structure promises the intact fiber structure and transmission mode,which efficiently enhances the temperature detection ability of graphene.From our simulation,we find that the temperature sensitivity can be electrically tuned over four orders of magnitude and achieve up to~3.34×10^(-3) dB/(cm·℃)when the graphene Fermi level is~35 meV higher than half the incident photon energy.Additionally,this sensitivity can be further improved by~10 times through optimizing the PCF structure(such as the fiber hole diameter)to enhance the light–matter interaction.Our results provide a new way for the design of the highly sensitive temperature sensors and broaden applications in all-fiber optoelectronic devices.展开更多
Surface acoustic wave(SAW)resonator with outstanding quality factors of 4829/6775 at the resonant/anti-resonant frequencies has been demonstrated on C-doped semi-insulating bulk GaN.The impact of device parameters inc...Surface acoustic wave(SAW)resonator with outstanding quality factors of 4829/6775 at the resonant/anti-resonant frequencies has been demonstrated on C-doped semi-insulating bulk GaN.The impact of device parameters including aspect ratio of length to width of resonators,number of interdigital transducers,and acoustic propagation direction on resonator performance have been studied.For the first time,we demonstrate wireless temperature sensing from 21.6 to 120℃ with a stable temperature coefficient of frequency of–24.3 ppm/℃ on bulk GaN-based SAW resonators.展开更多
Effect of anode area on temperature sensing ability is investigated for a vertical GaN Schottky-barrier-diode sensor.The current-voltage-temperature characteristics are comparable to each other for Schottky barrier di...Effect of anode area on temperature sensing ability is investigated for a vertical GaN Schottky-barrier-diode sensor.The current-voltage-temperature characteristics are comparable to each other for Schottky barrier diodes with different anode areas,excepting the series resistance.In the sub-threshold region,the contribution of series resistance on the sensitivity can be ignored due to the relatively small current.The sensitivity is dominated by the current density.A large anode area is helpful for enhancing the sensitivity at the same current level.In the fully turn-on region,the contribution of series resistance dominates the sensitivity.Unfortunately,a large series resistance degrades the temperature error and linearity,implying that a larger anode area will help to decrease the series resistance and to improve the sensing ability.展开更多
In order to control the working wavelength range of the fiber surface plasmon resonance(SPR)temperature sensor and realize the wavelength division multiplexing type multi-channel fiber SPR temperature sensor,by compre...In order to control the working wavelength range of the fiber surface plasmon resonance(SPR)temperature sensor and realize the wavelength division multiplexing type multi-channel fiber SPR temperature sensor,by comprehensively investigating the influence of liquids with different thermal-optical coefficients and solid packaging materials on the performance of fiber SPR temperature sensor,a dual-channel fiber SPR temperature sensor based on liquid-solid cascade encapsulation was designed and fabricated.The liquid temperature sensing stage encapsulated in capillary worked in 616.03 nm-639.05 nm band,the solid sensing stage coated with pouring sealant worked in 719.37 nm-825.27 nm band,and the two stages were cascaded to form a fiber dual-channel temperature sensor.The testing results indicated that when the temperature range was 35℃-95℃,the sensitivity of two-stage temperature detection was−0.384 nm/℃and−1.765 nm/℃respectively.The proposed fiber sensor has simple fabrication and excellent performance which can be widely used in various fields of dual-channel temperature measurement and temperature compensation.展开更多
The present study aims at improving the accuracy of weather forecast by providing useful information on the behavior and response of a sounding temperature sensor.A hybrid approach relying on Computational Fluid Dynam...The present study aims at improving the accuracy of weather forecast by providing useful information on the behavior and response of a sounding temperature sensor.A hybrid approach relying on Computational Fluid Dynamics and a genetic algorithm(GA)is used to simulate the system represented by the bead thermistor and the surrounding air.In particular,the influence of different lead angles,sensor lead length,and lead number is considered.The results have shown that when the length of the lead wire of the bead thermistor is increased,the radiation temperature rise is reduced;when the number of lead wire is four and the angle between the lead wires is 180°,the solar radiation angle has a scarce influence on the radiation temperature rise of the sounding temperature sensor.展开更多
The development of wearable technologies promotes the research of flexible sensors.It is hoped that a flexible sensor can collect different physiological data,such as temperature and respiratory rate(RR).The temperatu...The development of wearable technologies promotes the research of flexible sensors.It is hoped that a flexible sensor can collect different physiological data,such as temperature and respiratory rate(RR).The temperature of the exhaled gas is generally higher than that in the air,and the periodic change of temperature is related to the respiratory rate.In this work,we use platinum fiber and spandex fiber to prepare yarn-based temperature sensor with high tensile performance through hollow spindle wrapping spinning technology.After the measurement,the sensitivity of the sensor can reach at least 3.18×10^(-3)℃^(-1).We use the sensor and ordinary fabric mask to prepare a sensor mask that can monitor human respiratory signals to explore the performance of the sensor in RR measurement.The experimental results show that when measuring human RR,the yarn-based temperature sensor can accurately distinguish different respiratory states such as normal breathing,deep breathing,and rapid breathing while speaking.It is suggested that yarn-based temperature sensors can be used in medical fields such as real-time respiratory detection and temperature measurement.展开更多
Organic thin film transistors based on an F<sub>16</sub>CuPc/α6T pn heterojunction have been fabricated and analyzed to investigate the temperature dependence of electrical properties and apply in tempera...Organic thin film transistors based on an F<sub>16</sub>CuPc/α6T pn heterojunction have been fabricated and analyzed to investigate the temperature dependence of electrical properties and apply in temperature sensors. The mobility follows a thermally activated hopping process. At temperatures over 200 K, the value of thermal activation energy (E<sub>A</sub>) is 40. 1 meV, similar to that of the single-layer device. At temperatures ranging from 100 to 200 K, we have a second regime with a much lower E<sub>A</sub> of 16.3 meV, where the charge transport is dominated by shallow traps. Similarly, at temperatures above 200 K, threshold voltage (V<sub>T</sub>) increases linearly with decreasing temperature, and the variations of V<sub>T</sub> of 0.185 V/K is larger than the variation of V<sub>T</sub> (~0.020 V/K) in the single layer devices. This result is due to the interface dipolar charges. At temperatures ranging from 100 K to 200 K, we have a second regime with much lower variations of 0.090 V/K. By studying gate voltage (V<sub>G</sub>)-dependence temperature variation factor (k), the maximum value of k (~0.11 dec/K) could be obtained at V<sub>G</sub> = 5 V. Furthermore, the pn heterojunction device could be characterized as a temperature sensor well working at low operating voltages.展开更多
We propose a low-cost compact microfluidic temperature sensor by virtue of the temperature-dependent permittivity of liquid.The sensor is composed of a coplanar waveguide(CPW)transmission line loaded with three resona...We propose a low-cost compact microfluidic temperature sensor by virtue of the temperature-dependent permittivity of liquid.The sensor is composed of a coplanar waveguide(CPW)transmission line loaded with three resonators and a microfluidic plate with three channels.The resonant frequency of each resonator relies on the temperature-dependent dielectric property of liquid in corresponding channel,which therefore can be used to extract the temperature.The proposed sensor features a compact size and low cost since it requires only micro fluid volume instead of additional electronic components to produce significant frequency shift with changing temperature.Moreover,it exhibits decent accuracy and stability in a temperature sensing range from 30℃ to 95℃.A theoretical analysis of the sensor is provided,followed by the detailed characterization method,and a prototype is designed,manufactured,and measured to verify the theoretical analysis.展开更多
The temperature dependence of the bending loss light energy in multimode optical fibers is reported and analyzed. The work described in this paper aims to extend an initial previous analysis concerning planar optical ...The temperature dependence of the bending loss light energy in multimode optical fibers is reported and analyzed. The work described in this paper aims to extend an initial previous analysis concerning planar optical waveguides, light energy loss, to circular optical waveguides. The paper also presents à novel intrinsic fiber optic sensing device base on this study allowing to measure temperatures parameters. The simulation results are validated theoretically in the case of silica/silicone optical fiber. A comparison is done between results obtained with an optical fiber and the results obtained from the previous curved optical planar waveguide study. It is showed that the bending losses and the temperature measurement range depend on the curvature radius of an optical fiber or waveguide and the kind of the optical waveguide on which the sensing process is implemented.展开更多
This paper reports a novel technique for fabrication of a flexible skin with a temperature sensor array (40×1 sensors). A simplified MEMS technology using platinum resistors as sensing materials, which are sandwi...This paper reports a novel technique for fabrication of a flexible skin with a temperature sensor array (40×1 sensors). A simplified MEMS technology using platinum resistors as sensing materials, which are sandwiched between two polyimide layers as flexible substrates is developed. The two polyimide layers are deposited on top of a thin aluminum layer, which serves as a sacrificial layer such that the flexible skin can be released by metal etching and peeled off easily. The flexible skin with a temperature sensor array has a high mechanical flexibility and can be handily attached on a highly curved surface to detect tiny temperature distribution inside a small area. The sensor array shows a linear output and has a sensitivity of 7.5mV/℃ (prior to amplifiers) at a drive current of 1 mA. To demonstrate its applications, two examples have been demonstrated, including measurement of temperature distribution around a micro heater of a micro PCR (polymerase chain reaction) chip for DNA amplification and detection of separation point for flow over a circular cylinder. The development of the flexible skin with a temperature sensor array may be crucial for measuring temperature distribution on any curved surface in the fields of aerodynamics, space exploration, auto making and biomedical applications etc.展开更多
In high-speed cutting, natural thermocouple, artificial thermocouple and infrared radiation temperature measurement are usually adopted for measuring cutting temperature, but these methods have difficulty in measuring...In high-speed cutting, natural thermocouple, artificial thermocouple and infrared radiation temperature measurement are usually adopted for measuring cutting temperature, but these methods have difficulty in measuring transient temperature accurately of cutting area on account of low response speed and limited cutting condition. In this paper, NiCr/NiSi thin-film thermocouples(TFTCs) are fabricated according to temperature characteristic of cutting area in high-speed cutting by means of advanced twinned microwave electro cyclotron resonance(MW-ECR) plasma source enhanced radio frequency(RF) reaction non-balance magnetron sputtering technique, and can be used for transient cutting temperature measurement. The time constants of the TFTCs with different thermo-junction film width are measured at four kinds of sampling frequency by using Ultra-CFR short pulsed laser system that established. One-dimensional unsteady heat conduction model is constructed and the dynamic performance is analyzed theoretically. It can be seen from the analysis results that the NiCr/NiSi TFTCs are suitable for measuring transient temperature which varies quickly, the response speed of TFTCs can be obviously improved by reducing the thickness of thin-film, and the area of thermo-junction has little influence on dynamic response time. The dynamic calibration experiments are made on the constructed dynamic calibration system, and the experimental results confirm that sampling frequency should be larger than 50 kHz in dynamic measurement for stable response time, and the shortest response time is 0.042 ms. Measurement methods and devices of cutting heat and cutting temperature measurement are developed and improved by this research, which provide practical methods and instruments in monitoring cutting heat and cutting temperature for research and production in high-speed machining.展开更多
Metal-coated fiber Bragg grating(FBG)temperature sensors were prepared via electroless nickel(EN)plating and tin electroplating methods on the surface of normal bare FBG.The surface morphologies of the metal-coated la...Metal-coated fiber Bragg grating(FBG)temperature sensors were prepared via electroless nickel(EN)plating and tin electroplating methods on the surface of normal bare FBG.The surface morphologies of the metal-coated layers were observed under a metallographic microscope.The effects of pretreatment sequence,pH value of EN plating solution and current density of electroplating on the performance of the metal-coated layers were analyzed.Meanwhile, the Bragg wavelength shift induced by temperature was monitored by an optical spectrum analyzer.Sensitivity of the metal-coated FBG(MFBG)sensor was almost two times that of normal bare FBG sensor.The measuring temperature of the MFBG sensor could be up to 280°C,which was much better than that of conventional FBG sensor.展开更多
A highly sensitive optical fiber temperature sensor based on a section of liquid-filled silica capillary tube(SCT)between single mode fibers is proposed. Two micro-holes are drilled on two sides of SCT directly by usi...A highly sensitive optical fiber temperature sensor based on a section of liquid-filled silica capillary tube(SCT)between single mode fibers is proposed. Two micro-holes are drilled on two sides of SCT directly by using femtosecond laser micromachining, and liquid polymer is filled into the SCT through the micro-holes without any air bubbles and then sealed by using ultra-violet(UV) cure adhesive. The sidewall of the SCT forms a Fabry–Perot resonator, and loss peaks are achieved in the transmission spectrum of the SCT at the resonant wavelength. The resonance condition can be influenced by the refractive index variation of the liquid polymer filled in SCT, which is sensitive to temperature due to its high thermooptical coefficient(-2.98 × 10^-4℃^-1). The experimental result shows that the temperature sensitivity of the proposed fiber structure reaches 5.09 nm/℃ with a perfect linearity of 99.8%. In addition, it exhibits good repeatability and reliability in temperature sensing application.展开更多
A temperature sensor is demonstrated and fabricated by coating the single-mode tapered optical fiber with temperature-sensitive silicone rubber. It works on the change of the evanescent fields in the tapered optical f...A temperature sensor is demonstrated and fabricated by coating the single-mode tapered optical fiber with temperature-sensitive silicone rubber. It works on the change of the evanescent fields in the tapered optical fiber. Small changes in the refractive index of coating film greatly influence the power of evanescent fields, which modulate the transmission optical power in the waist region. The range of temperature measured is from 20°C to 70°C. The results show that the temperature sensor has high temperature sensitivity (0.012 mW/°C) and good repeatability.展开更多
Yb3+:Er3+co-doped oxy-fluoride ceramics glass has been prepared.The mechanism of up-conversion emissions about Er3+was discussed,and the temperature properties of green up-conversion fluorescence between 303 and 823 K...Yb3+:Er3+co-doped oxy-fluoride ceramics glass has been prepared.The mechanism of up-conversion emissions about Er3+was discussed,and the temperature properties of green up-conversion fluorescence between 303 and 823 K were investigated.The results show that the sensitivity of this sample reaches its maximum value,about 0.0047 K 1,when the temperature is 383 K,indicating that this kind of sample can be used as high temperature and high sensitivity optical temperature sensor.展开更多
In the present study,anodic films on aluminium alloy was used as the dielectric layer for Cu thinfilm temperature sensor,and then Cu film was deposited by unbalanced magnetron sputtering ion plating as the sensitive l...In the present study,anodic films on aluminium alloy was used as the dielectric layer for Cu thinfilm temperature sensor,and then Cu film was deposited by unbalanced magnetron sputtering ion plating as the sensitive layer.Microstructure and surface morphologies of Cu film were investigated by optical microscope(OM),atomic force microscope(AFM) and scanning electron microscope(SEM).Electrical properties of Cu thin-film temperature sensor were tested by four-point probe technique and Digit Multimeter.The results showed that the surface roughness of anodic films can be reduced from Ra 58.096 nm to Ra 16.335 nm by proper polishing.Continual Cu stripes can be obtained both on polished anodic alumina film and smooth alumina wafer by etching after Cu film annealing.The resistivity of Cu films before and after 300 ℃ as well as 400 ℃ annealing are 12.48 mΩ·cm,5.48 mΩ·cm and 4.83 mΩ·cm,respectively.The resistances of Cu thin-film temperature sensor in 70 ℃ and 0 ℃ are 946.5 Ω and 761.15 Ω respectively.The temperature coefficient of resistivity(TCR) of the sensor is 3479 × 10^(- 6) /℃.展开更多
基金Supported by the Scientific Research and Technology Development Project of Wuzhou Meteorological Bureau(WUQIKEZ2021009).
文摘Developing a calibration and collection system of platinum resistance temperature sensor using Python language environment can read the information returned by the serial port and automatically generate an"Temperature Sensor Calibration Record Table"excel table with the current date as the file name.It can collect data from 10 platinum resistance temperature sensors at once,achieving automation and improving work efficiency.
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.
文摘An E-type high-precision temperature sensor, which is adopted for upper air meteorology, was proposed in this paper. A computational fluid dynamics(CFD) method was implemented to analyze temperature rise induced by solar radiation at different altitudes and solar radiation intensities. A temperature rise correction equation was obtained by fitting the CFD results using a Broyden-Fletcher-Goldfarb-Shanno(BFGS) method. To verify the performance of the temperature sensor, an experimental platform was constructed. Through simulations and experiments, the relationship among the altitude, solar radiation intensity and radiation temperature rise was obtaned. The root-mean-square error(RMSE) between the temperature rise derived from the correction equation and that derived from the experiments is 0.013 K. The sample determination coefficient r2 of the solar radiation error correction equation is 0.9975.
基金supported in part by the National Natural Science Foundation of China ( 51375378, 91323303 )the 13th Fok Ying Tung Education Foundation ( 132010 )+5 种基金the Science and Technology Research Project of Shaanxi (2012KJXX-01)the Fundamental Research Funds for the Central Universities ( 2012jdgz08 )the Major National Science and Technology Project ( 2011ZX04004-061 )the 111 Program ( B12016 )National Key Scientific Instrument and Equipment Development Projects of China ( 2012YQ03026101 )The China Scholarship Council
文摘Resonant temperature sensors have drawn considerable attention for their advantages such as high sensitivity,digitized signal output and high precision.This paper presents a new type of resonant temperature sensor,which uses capacitive micromachined ultrasonic transducer(CMUT)as the sensing element.A lumped electro-mechanical-thermal model was established to show its working principle for temperature measurement.The theoretical model explicitly explains the thermally induced changes in the resonant frequency of the CMUT.Then,the finite element method was used to further investigate the sensing performance.The numerical results agree well with the established analytical model qualitatively.The numerical results show that the resonant frequency varies linearly with the temperature over the range of 20℃to 140℃ at the first four vibrating modes.However,the first order vibrating mode shows a higher sensitivity than the other three higher modes.When working at the first order vibrating mode,the temperature coefficient of the resonance frequency(TCf)can reach as high as-1114.3 ppm/℃ at a bias voltage equal to 90%of the collapse voltage of the MCUT.The corresponding nonlinear error was as low as 1.18%.It is discovered that the sensing sensitivity is dependent on the applied bias voltages.A higher sensitivity can be achieved by increasing the bias voltages.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52021006,52025023,51991342,and 11888101)the Key R&D Program of Guangdong Province,China(Grant Nos.2019B010931001,2020B010189001,and 2018B030327001)+6 种基金the Pearl River Talent Recruitment Program of Guangdong Province,China(Grant No.2019ZT08C321)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000)Beijing Natural Science Foundation,China(Grant No.JQ19004)Beijing Municipal Science&Technology Commission,China(Grant No.Z181100004818003)the China Postdoctoral Science Foundation(Grant No.2020M680177)National Postdoctoral Program for Innovative Talents of China(Grant No.BX20190016)China Postdoctoral Science Foundation(Grant No.2019M660280).
文摘Optical fiber temperature sensors have been widely employed in enormous areas ranging from electric power industry,medical treatment,ocean dynamics to aerospace.Recently,graphene optical fiber temperature sensors attract tremendous attention for their merits of simple structure and direct power detecting ability.However,these sensors based on transfer techniques still have limitations in the relatively low sensitivity or distortion of the transmission characteristics,due to the unsuitable Fermi level of graphene and the destruction of fiber structure,respectively.Here,we propose a tunable and highly sensitive temperature sensor based on graphene photonic crystal fiber(Gr-PCF)with the non-destructive integration of graphene into the holes of PCF.This hybrid structure promises the intact fiber structure and transmission mode,which efficiently enhances the temperature detection ability of graphene.From our simulation,we find that the temperature sensitivity can be electrically tuned over four orders of magnitude and achieve up to~3.34×10^(-3) dB/(cm·℃)when the graphene Fermi level is~35 meV higher than half the incident photon energy.Additionally,this sensitivity can be further improved by~10 times through optimizing the PCF structure(such as the fiber hole diameter)to enhance the light–matter interaction.Our results provide a new way for the design of the highly sensitive temperature sensors and broaden applications in all-fiber optoelectronic devices.
基金The research is supported by the National Natural Sciences Foundation of China(Grant No.61974137)the One Hundred Person project of the Chinese Academy of Science.
文摘Surface acoustic wave(SAW)resonator with outstanding quality factors of 4829/6775 at the resonant/anti-resonant frequencies has been demonstrated on C-doped semi-insulating bulk GaN.The impact of device parameters including aspect ratio of length to width of resonators,number of interdigital transducers,and acoustic propagation direction on resonator performance have been studied.For the first time,we demonstrate wireless temperature sensing from 21.6 to 120℃ with a stable temperature coefficient of frequency of–24.3 ppm/℃ on bulk GaN-based SAW resonators.
基金supported by the Scientific Research Support Foundation for Introduced High-Level Talents of Shenyang Ligong University(Grant No.1010147000914)the Science and Technology Program of Ningbo(Grant No.2019B10129)。
文摘Effect of anode area on temperature sensing ability is investigated for a vertical GaN Schottky-barrier-diode sensor.The current-voltage-temperature characteristics are comparable to each other for Schottky barrier diodes with different anode areas,excepting the series resistance.In the sub-threshold region,the contribution of series resistance on the sensitivity can be ignored due to the relatively small current.The sensitivity is dominated by the current density.A large anode area is helpful for enhancing the sensitivity at the same current level.In the fully turn-on region,the contribution of series resistance dominates the sensitivity.Unfortunately,a large series resistance degrades the temperature error and linearity,implying that a larger anode area will help to decrease the series resistance and to improve the sensing ability.
基金supported by the National Natural Science Foundation of China(Grant No.61705025)the Natural Science Foundation of Heilongjiang Province,China(Grant No.F2018027)+3 种基金partially supported by Chongqing Natural Science Foundation(Grant Nos.cstc2019jcyj-msxmX0431 and cstc2018jcyjAX0817)the Science and Technology Project Affiliated to the Education Department of Chongqing Municipality(Grant Nos.KJQN201801217,KJQN201901226,and KJ1710247)Chongqing Key Laboratory of Geological Environment Monitoring and Disaster Early-Warning in Three Gorges Reservoir Area(Grant Nos.ZD2020A0103 and ZD2020A0102)the Fundamental Research Funds for Chongqing Three Gorges University of China(Grant No.19ZDPY08).
文摘In order to control the working wavelength range of the fiber surface plasmon resonance(SPR)temperature sensor and realize the wavelength division multiplexing type multi-channel fiber SPR temperature sensor,by comprehensively investigating the influence of liquids with different thermal-optical coefficients and solid packaging materials on the performance of fiber SPR temperature sensor,a dual-channel fiber SPR temperature sensor based on liquid-solid cascade encapsulation was designed and fabricated.The liquid temperature sensing stage encapsulated in capillary worked in 616.03 nm-639.05 nm band,the solid sensing stage coated with pouring sealant worked in 719.37 nm-825.27 nm band,and the two stages were cascaded to form a fiber dual-channel temperature sensor.The testing results indicated that when the temperature range was 35℃-95℃,the sensitivity of two-stage temperature detection was−0.384 nm/℃and−1.765 nm/℃respectively.The proposed fiber sensor has simple fabrication and excellent performance which can be widely used in various fields of dual-channel temperature measurement and temperature compensation.
文摘The present study aims at improving the accuracy of weather forecast by providing useful information on the behavior and response of a sounding temperature sensor.A hybrid approach relying on Computational Fluid Dynamics and a genetic algorithm(GA)is used to simulate the system represented by the bead thermistor and the surrounding air.In particular,the influence of different lead angles,sensor lead length,and lead number is considered.The results have shown that when the length of the lead wire of the bead thermistor is increased,the radiation temperature rise is reduced;when the number of lead wire is four and the angle between the lead wires is 180°,the solar radiation angle has a scarce influence on the radiation temperature rise of the sounding temperature sensor.
基金National Natural Science Foundation of China(Nos.12002085 and 51603039)Shanghai Pujiang Program,China(No.19PJC002)+2 种基金Fundamental Research Funds for the Central Universities of ministry of Education of China(Nos.2232017D-12)Key Laboratory of Textile Science and Technology(Donghua University),Ministry of Education,China(No.KLTST201623)Initial Research Funds for Young Teachers of Donghua University,China(No.104-07-005388)。
文摘The development of wearable technologies promotes the research of flexible sensors.It is hoped that a flexible sensor can collect different physiological data,such as temperature and respiratory rate(RR).The temperature of the exhaled gas is generally higher than that in the air,and the periodic change of temperature is related to the respiratory rate.In this work,we use platinum fiber and spandex fiber to prepare yarn-based temperature sensor with high tensile performance through hollow spindle wrapping spinning technology.After the measurement,the sensitivity of the sensor can reach at least 3.18×10^(-3)℃^(-1).We use the sensor and ordinary fabric mask to prepare a sensor mask that can monitor human respiratory signals to explore the performance of the sensor in RR measurement.The experimental results show that when measuring human RR,the yarn-based temperature sensor can accurately distinguish different respiratory states such as normal breathing,deep breathing,and rapid breathing while speaking.It is suggested that yarn-based temperature sensors can be used in medical fields such as real-time respiratory detection and temperature measurement.
文摘Organic thin film transistors based on an F<sub>16</sub>CuPc/α6T pn heterojunction have been fabricated and analyzed to investigate the temperature dependence of electrical properties and apply in temperature sensors. The mobility follows a thermally activated hopping process. At temperatures over 200 K, the value of thermal activation energy (E<sub>A</sub>) is 40. 1 meV, similar to that of the single-layer device. At temperatures ranging from 100 to 200 K, we have a second regime with a much lower E<sub>A</sub> of 16.3 meV, where the charge transport is dominated by shallow traps. Similarly, at temperatures above 200 K, threshold voltage (V<sub>T</sub>) increases linearly with decreasing temperature, and the variations of V<sub>T</sub> of 0.185 V/K is larger than the variation of V<sub>T</sub> (~0.020 V/K) in the single layer devices. This result is due to the interface dipolar charges. At temperatures ranging from 100 K to 200 K, we have a second regime with much lower variations of 0.090 V/K. By studying gate voltage (V<sub>G</sub>)-dependence temperature variation factor (k), the maximum value of k (~0.11 dec/K) could be obtained at V<sub>G</sub> = 5 V. Furthermore, the pn heterojunction device could be characterized as a temperature sensor well working at low operating voltages.
基金Project supported by the Natural Science Foundation of Zhejiang Province,China(Grant No.LQ19F010007)the National Natural Science Foundation of China(Grants Nos.61901146 and 61874038)the Smart City Collaborative Innovation Center of Zhejiang Province,China
文摘We propose a low-cost compact microfluidic temperature sensor by virtue of the temperature-dependent permittivity of liquid.The sensor is composed of a coplanar waveguide(CPW)transmission line loaded with three resonators and a microfluidic plate with three channels.The resonant frequency of each resonator relies on the temperature-dependent dielectric property of liquid in corresponding channel,which therefore can be used to extract the temperature.The proposed sensor features a compact size and low cost since it requires only micro fluid volume instead of additional electronic components to produce significant frequency shift with changing temperature.Moreover,it exhibits decent accuracy and stability in a temperature sensing range from 30℃ to 95℃.A theoretical analysis of the sensor is provided,followed by the detailed characterization method,and a prototype is designed,manufactured,and measured to verify the theoretical analysis.
文摘The temperature dependence of the bending loss light energy in multimode optical fibers is reported and analyzed. The work described in this paper aims to extend an initial previous analysis concerning planar optical waveguides, light energy loss, to circular optical waveguides. The paper also presents à novel intrinsic fiber optic sensing device base on this study allowing to measure temperatures parameters. The simulation results are validated theoretically in the case of silica/silicone optical fiber. A comparison is done between results obtained with an optical fiber and the results obtained from the previous curved optical planar waveguide study. It is showed that the bending losses and the temperature measurement range depend on the curvature radius of an optical fiber or waveguide and the kind of the optical waveguide on which the sensing process is implemented.
文摘This paper reports a novel technique for fabrication of a flexible skin with a temperature sensor array (40×1 sensors). A simplified MEMS technology using platinum resistors as sensing materials, which are sandwiched between two polyimide layers as flexible substrates is developed. The two polyimide layers are deposited on top of a thin aluminum layer, which serves as a sacrificial layer such that the flexible skin can be released by metal etching and peeled off easily. The flexible skin with a temperature sensor array has a high mechanical flexibility and can be handily attached on a highly curved surface to detect tiny temperature distribution inside a small area. The sensor array shows a linear output and has a sensitivity of 7.5mV/℃ (prior to amplifiers) at a drive current of 1 mA. To demonstrate its applications, two examples have been demonstrated, including measurement of temperature distribution around a micro heater of a micro PCR (polymerase chain reaction) chip for DNA amplification and detection of separation point for flow over a circular cylinder. The development of the flexible skin with a temperature sensor array may be crucial for measuring temperature distribution on any curved surface in the fields of aerodynamics, space exploration, auto making and biomedical applications etc.
基金supported by National Natural Science Foundation of China(Grant No.50775210)Liaoning Provincial Natural Science Foundation of China(Grant No.20062143)Liaoning Provincial Universities Science and Technology Program of China(Grant No.05L023)
文摘In high-speed cutting, natural thermocouple, artificial thermocouple and infrared radiation temperature measurement are usually adopted for measuring cutting temperature, but these methods have difficulty in measuring transient temperature accurately of cutting area on account of low response speed and limited cutting condition. In this paper, NiCr/NiSi thin-film thermocouples(TFTCs) are fabricated according to temperature characteristic of cutting area in high-speed cutting by means of advanced twinned microwave electro cyclotron resonance(MW-ECR) plasma source enhanced radio frequency(RF) reaction non-balance magnetron sputtering technique, and can be used for transient cutting temperature measurement. The time constants of the TFTCs with different thermo-junction film width are measured at four kinds of sampling frequency by using Ultra-CFR short pulsed laser system that established. One-dimensional unsteady heat conduction model is constructed and the dynamic performance is analyzed theoretically. It can be seen from the analysis results that the NiCr/NiSi TFTCs are suitable for measuring transient temperature which varies quickly, the response speed of TFTCs can be obviously improved by reducing the thickness of thin-film, and the area of thermo-junction has little influence on dynamic response time. The dynamic calibration experiments are made on the constructed dynamic calibration system, and the experimental results confirm that sampling frequency should be larger than 50 kHz in dynamic measurement for stable response time, and the shortest response time is 0.042 ms. Measurement methods and devices of cutting heat and cutting temperature measurement are developed and improved by this research, which provide practical methods and instruments in monitoring cutting heat and cutting temperature for research and production in high-speed machining.
基金the National Natural Science Foundation of China(No.60777038).
文摘Metal-coated fiber Bragg grating(FBG)temperature sensors were prepared via electroless nickel(EN)plating and tin electroplating methods on the surface of normal bare FBG.The surface morphologies of the metal-coated layers were observed under a metallographic microscope.The effects of pretreatment sequence,pH value of EN plating solution and current density of electroplating on the performance of the metal-coated layers were analyzed.Meanwhile, the Bragg wavelength shift induced by temperature was monitored by an optical spectrum analyzer.Sensitivity of the metal-coated FBG(MFBG)sensor was almost two times that of normal bare FBG sensor.The measuring temperature of the MFBG sensor could be up to 280°C,which was much better than that of conventional FBG sensor.
基金Project supported by the Scientific Research Project of Institutions of Higher Learning in Inner Mongolia Autonomous Region,China(Grant No.NJZY19214)
文摘A highly sensitive optical fiber temperature sensor based on a section of liquid-filled silica capillary tube(SCT)between single mode fibers is proposed. Two micro-holes are drilled on two sides of SCT directly by using femtosecond laser micromachining, and liquid polymer is filled into the SCT through the micro-holes without any air bubbles and then sealed by using ultra-violet(UV) cure adhesive. The sidewall of the SCT forms a Fabry–Perot resonator, and loss peaks are achieved in the transmission spectrum of the SCT at the resonant wavelength. The resonance condition can be influenced by the refractive index variation of the liquid polymer filled in SCT, which is sensitive to temperature due to its high thermooptical coefficient(-2.98 × 10^-4℃^-1). The experimental result shows that the temperature sensitivity of the proposed fiber structure reaches 5.09 nm/℃ with a perfect linearity of 99.8%. In addition, it exhibits good repeatability and reliability in temperature sensing application.
基金Project supported by the Shanghai Leading Academic Discipline Project (Grant No.S30108)the Universities Foster Innovation Foundation Projects for Major Projects in Ministry of Education (Grant No.708041)
文摘A temperature sensor is demonstrated and fabricated by coating the single-mode tapered optical fiber with temperature-sensitive silicone rubber. It works on the change of the evanescent fields in the tapered optical fiber. Small changes in the refractive index of coating film greatly influence the power of evanescent fields, which modulate the transmission optical power in the waist region. The range of temperature measured is from 20°C to 70°C. The results show that the temperature sensor has high temperature sensitivity (0.012 mW/°C) and good repeatability.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10804015 )the Science Foundation of the Education Department of Liaoning Province of China (Grant No. 2009A417)
文摘Yb3+:Er3+co-doped oxy-fluoride ceramics glass has been prepared.The mechanism of up-conversion emissions about Er3+was discussed,and the temperature properties of green up-conversion fluorescence between 303 and 823 K were investigated.The results show that the sensitivity of this sample reaches its maximum value,about 0.0047 K 1,when the temperature is 383 K,indicating that this kind of sample can be used as high temperature and high sensitivity optical temperature sensor.
基金Sponsored by the National Natural Science Foundation of China(Grant No. 60971020)
文摘In the present study,anodic films on aluminium alloy was used as the dielectric layer for Cu thinfilm temperature sensor,and then Cu film was deposited by unbalanced magnetron sputtering ion plating as the sensitive layer.Microstructure and surface morphologies of Cu film were investigated by optical microscope(OM),atomic force microscope(AFM) and scanning electron microscope(SEM).Electrical properties of Cu thin-film temperature sensor were tested by four-point probe technique and Digit Multimeter.The results showed that the surface roughness of anodic films can be reduced from Ra 58.096 nm to Ra 16.335 nm by proper polishing.Continual Cu stripes can be obtained both on polished anodic alumina film and smooth alumina wafer by etching after Cu film annealing.The resistivity of Cu films before and after 300 ℃ as well as 400 ℃ annealing are 12.48 mΩ·cm,5.48 mΩ·cm and 4.83 mΩ·cm,respectively.The resistances of Cu thin-film temperature sensor in 70 ℃ and 0 ℃ are 946.5 Ω and 761.15 Ω respectively.The temperature coefficient of resistivity(TCR) of the sensor is 3479 × 10^(- 6) /℃.
