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
The combustion chamber temperature of newgeneration aircraft engines can reach an ultrahigh temperature of 1800℃,making temperature monitoring of key components crucial.Thin-film thermocouples(TFTCs)are highly sensit...The combustion chamber temperature of newgeneration aircraft engines can reach an ultrahigh temperature of 1800℃,making temperature monitoring of key components crucial.Thin-film thermocouples(TFTCs)are highly sensitive and have rapid response times;however,their upper-temperature limit remains below 1800℃.This study proposes an ultrahightemperature film thermocouple,which is enhanced by yttriastabilized zirconia(YSZ)for positive films,indium oxide(In_(2)O_(3))for negative films,and aluminum oxide(Al_(2)O_(3))for protective films.The thermocouple is designed on the basis of temperature measurement principles,first principles,and simulations,and it is manufactured via screen printing.The results indicate that the maximum working temperature is 1850℃.In experiments with different doping ratios at 1800℃,the thermocouple achieves a maximum temperature electromotive force(TEMF)of 258.5 mV and a maximum Seebeck coefficient of 180.9μV/℃,with an In_(2)O_(3):YSZ92(ZrO_(2)(92 wt%):Y_(2)O_(3)(8 wt%))ratio of 9:1 in wt%.Through the lumped heat capacity method,the response time was measured at 2.8 ms,which demonstrated good dynamic response characteristics.A film thermocouple was successfully utilized to measure a gas temperature of 1090℃ at the outlet of an air turbine rocket(ATR)engine,confirming its high-temperature operational capability.To improve the repeatability of the TFTCs without affecting their thermoelectric outputs,a convolutional neural network-long short-term memory network(CNN-LSTM)-attention neural network is implemented to mitigate the repeatability errors,achieving a high repeatability of 99.53%.Additionally,the compensated temperature data are compared with those obtained from a standard B-type thermocouple,showing a full-scale error of±0.73%FS.This study provides a feasible solution for ultrahigh temperature measurements.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
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supported in part by the National Key R&D Program(No.2023YFB3209600)the National Natural Science Foundation of China(No.52475570).
文摘The combustion chamber temperature of newgeneration aircraft engines can reach an ultrahigh temperature of 1800℃,making temperature monitoring of key components crucial.Thin-film thermocouples(TFTCs)are highly sensitive and have rapid response times;however,their upper-temperature limit remains below 1800℃.This study proposes an ultrahightemperature film thermocouple,which is enhanced by yttriastabilized zirconia(YSZ)for positive films,indium oxide(In_(2)O_(3))for negative films,and aluminum oxide(Al_(2)O_(3))for protective films.The thermocouple is designed on the basis of temperature measurement principles,first principles,and simulations,and it is manufactured via screen printing.The results indicate that the maximum working temperature is 1850℃.In experiments with different doping ratios at 1800℃,the thermocouple achieves a maximum temperature electromotive force(TEMF)of 258.5 mV and a maximum Seebeck coefficient of 180.9μV/℃,with an In_(2)O_(3):YSZ92(ZrO_(2)(92 wt%):Y_(2)O_(3)(8 wt%))ratio of 9:1 in wt%.Through the lumped heat capacity method,the response time was measured at 2.8 ms,which demonstrated good dynamic response characteristics.A film thermocouple was successfully utilized to measure a gas temperature of 1090℃ at the outlet of an air turbine rocket(ATR)engine,confirming its high-temperature operational capability.To improve the repeatability of the TFTCs without affecting their thermoelectric outputs,a convolutional neural network-long short-term memory network(CNN-LSTM)-attention neural network is implemented to mitigate the repeatability errors,achieving a high repeatability of 99.53%.Additionally,the compensated temperature data are compared with those obtained from a standard B-type thermocouple,showing a full-scale error of±0.73%FS.This study provides a feasible solution for ultrahigh temperature measurements.
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.
