Temperature is an important physical variable that indicates the condition of the human body and artificial systems.Advanced wearable applications require the development of temperature sensors with different form fac...Temperature is an important physical variable that indicates the condition of the human body and artificial systems.Advanced wearable applications require the development of temperature sensors with different form factors.In this study,a fiber-shaped thermoelectric temperature sensor is fabricated using a continuous graphene fiber whose two halves possess different reduction states.A seamless junction is formed by partially reducing a wet-spun graphene oxide fiber with hydroiodic acid(HI)solutions of different concentrations.One-half of the fiber is mildly reduced with 0.97 wt%HI,while the other half is highly reduced with 30.6 wt%HI.The different reduction states of the graphene composite fiber result in different Seebeck coefficients,allowing for the fabrication of a fiber-shaped graphene thermocou-ple without any laborious assembly.The flexible graphene thermocouple exhibits high sensitivity with a thermopower of 12.5μV K^(-1)in the temperature range of room temperature to∼70℃.Furthermore,it exhibits high linearity with a correlation coefficient exceeding 0.995 and fast response with a time constant of 0.24 s.Owing to its mechanical robustness and flexibility,the stand-alone graphene ther-mocouple can be knitted into a cotton fabric glove,which presents a fast response to environmental changes without any external power source.This work offers a unique fabrication method for producing a high-performance,flexible thermocouple that features a seamless and clear junction without the use of additional materials.This alternative method eliminates the complicated assembly processes typically required for conventional thermocouples.展开更多
Characterized by thinness,lightness and flexibility,flexible thin-film temperature sensors can be tightly fitted to different shapes of surfaces to measure their surface temperatures.However,the deformation in sensor ...Characterized by thinness,lightness and flexibility,flexible thin-film temperature sensors can be tightly fitted to different shapes of surfaces to measure their surface temperatures.However,the deformation in sensor installation and stress caused during temperature testing can lead to the deterioration in testing capability of the sensor.In this paper,the Peano structure is used to optimize the thin-film design for reducing the internal stress value.Additionally,multiwalled carbon nanotubes(MWCNTs)are doped into the thermoelectric material(Indium oxide,In2O3)to construct a powder-fiber staggered adhesive thin-film micro-structure,with the parameters involved in the co-conformal deposition of the thin-film optimized.Unaffected by force/deformation,a thermocouple-type flexible thin-film temperature sensor with high stability and reliability is developed.This sensor is considered promising for contact/non-contact(gas/liquid shock,etc.)measurement.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Ministry of Science and ICT(Nos.2022R1A2B5B02002413,2022R1A4A1031182,and 2019R1A2C2089785)supported by the Korea Institute of Industrial Technology(kitech JA-20-0001).
文摘Temperature is an important physical variable that indicates the condition of the human body and artificial systems.Advanced wearable applications require the development of temperature sensors with different form factors.In this study,a fiber-shaped thermoelectric temperature sensor is fabricated using a continuous graphene fiber whose two halves possess different reduction states.A seamless junction is formed by partially reducing a wet-spun graphene oxide fiber with hydroiodic acid(HI)solutions of different concentrations.One-half of the fiber is mildly reduced with 0.97 wt%HI,while the other half is highly reduced with 30.6 wt%HI.The different reduction states of the graphene composite fiber result in different Seebeck coefficients,allowing for the fabrication of a fiber-shaped graphene thermocou-ple without any laborious assembly.The flexible graphene thermocouple exhibits high sensitivity with a thermopower of 12.5μV K^(-1)in the temperature range of room temperature to∼70℃.Furthermore,it exhibits high linearity with a correlation coefficient exceeding 0.995 and fast response with a time constant of 0.24 s.Owing to its mechanical robustness and flexibility,the stand-alone graphene ther-mocouple can be knitted into a cotton fabric glove,which presents a fast response to environmental changes without any external power source.This work offers a unique fabrication method for producing a high-performance,flexible thermocouple that features a seamless and clear junction without the use of additional materials.This alternative method eliminates the complicated assembly processes typically required for conventional thermocouples.
基金supported by Yangtze River Delta(Bengbu)Industry-Education Integration and Collaboration Center of State Key Laboratory for Manufacturing Systems Engineering,National Natural Science Foundation of China(52293405,52505633)AVIC Industry Academia-Research Cooperation Project(HFZL2023CXY011)+2 种基金Postdoctora Innovative Talent Program of China(BX20240278)China Postdoctoral Science Foundation(2025M773615)Key Laboratory for Precision/Non-traditional Machining and Micromanufacturing Technology of Ministry of Education Open Project Fund,Dalian University of Technology(B202503).
文摘Characterized by thinness,lightness and flexibility,flexible thin-film temperature sensors can be tightly fitted to different shapes of surfaces to measure their surface temperatures.However,the deformation in sensor installation and stress caused during temperature testing can lead to the deterioration in testing capability of the sensor.In this paper,the Peano structure is used to optimize the thin-film design for reducing the internal stress value.Additionally,multiwalled carbon nanotubes(MWCNTs)are doped into the thermoelectric material(Indium oxide,In2O3)to construct a powder-fiber staggered adhesive thin-film micro-structure,with the parameters involved in the co-conformal deposition of the thin-film optimized.Unaffected by force/deformation,a thermocouple-type flexible thin-film temperature sensor with high stability and reliability is developed.This sensor is considered promising for contact/non-contact(gas/liquid shock,etc.)measurement.
