Flexible strain sensors are revolutionizing human–machine interactions and next-generation health care by enabling realtime monitoring of human motion and precision medical treatment.However,developing lightweight fl...Flexible strain sensors are revolutionizing human–machine interactions and next-generation health care by enabling realtime monitoring of human motion and precision medical treatment.However,developing lightweight flexible strain sensors that combine high sensitivity with a broad monitoring range remains a significant challenge.To address this challenge,an advanced structural engineering strategy based on the sodium chloride(NaCl)template sacrificial method is employed to simultaneously increase sensitivity and mechanical robustness.By leveraging a NaCl template sacrificial method,a hierarchical synergistic conductive network is constructed within the thermoplastic polyurethane(TPU)matrix formed via in situ growth.This design enables ultra-high sensitivity across a broad strain range,offering promising potential for wearable sensing applications.The resulting sensor exhibits exceptional performance characteristics,including a low detection limit(0.176%),high sensitivity(gage factor,GF=331.7),wide sensing range(up to 230.1%),rapid response/recovery times(133 ms/133 ms),and remarkable durability exceeding 4000 cycles.Furthermore,the sensor demonstrated excellent electrothermal conversion performance with a positive temperature coefficient of 0.00207°C^(−1)and an achievable saturation temperature of 54.2°C(1.0 A).Finally,the sensor was successfully integrated into a smart wearable system,enabling precise recognition and classification of multiple gestures through machine learning algorithms while also exhibiting significant potential for inflammation hyperthermia therapy.展开更多
Flexible wearable electronics have garnered substantial attention as promising alternatives to traditional rigid metallic conductors,particularly for personal health monitoring and bioinspired skin applications.Howeve...Flexible wearable electronics have garnered substantial attention as promising alternatives to traditional rigid metallic conductors,particularly for personal health monitoring and bioinspired skin applications.However,these technologies face persistent challenges,including low sensitivity,limited mechanical strength,and difficulty in capturing weak signals.To address these issues,this study developed a hierarchical sandwich-structured piezoresistive foam sensor using phase inversion and NaCl sacrificial templating methods.The sensor exhibits an exceptional sensitivity of up to 83.4 kPa⁻1 under an ultralow detection pressure of 2.43 Pa.By optimizing the foam porosity,its mechanical performance was significantly enhanced,reaching a tensile fracture elongation of 257.3%at 73.42%porosity.The hierarchical sandwich structure provided mechanical buffering and layer-enhancement functionalities for dynamic responses,whereas the nanostructure further refined signal acquisition and interference resistance.Signal analysis using discrete wavelet transform(DWT)and continuous wavelet transform(CWT)enables multiscale and multifrequency characterization of arterial resistance signals under varying applied pressures.These findings underscore the sensor’s ability to capture weak signals and analyze complex pulse dynamics.This advancement paves the way for the extensive application of multifunctional sensors in smart devices and health care.This method offers a robust scientific basis for further understanding and quantifying arterial pulse characteristics.展开更多
文摘Flexible strain sensors are revolutionizing human–machine interactions and next-generation health care by enabling realtime monitoring of human motion and precision medical treatment.However,developing lightweight flexible strain sensors that combine high sensitivity with a broad monitoring range remains a significant challenge.To address this challenge,an advanced structural engineering strategy based on the sodium chloride(NaCl)template sacrificial method is employed to simultaneously increase sensitivity and mechanical robustness.By leveraging a NaCl template sacrificial method,a hierarchical synergistic conductive network is constructed within the thermoplastic polyurethane(TPU)matrix formed via in situ growth.This design enables ultra-high sensitivity across a broad strain range,offering promising potential for wearable sensing applications.The resulting sensor exhibits exceptional performance characteristics,including a low detection limit(0.176%),high sensitivity(gage factor,GF=331.7),wide sensing range(up to 230.1%),rapid response/recovery times(133 ms/133 ms),and remarkable durability exceeding 4000 cycles.Furthermore,the sensor demonstrated excellent electrothermal conversion performance with a positive temperature coefficient of 0.00207°C^(−1)and an achievable saturation temperature of 54.2°C(1.0 A).Finally,the sensor was successfully integrated into a smart wearable system,enabling precise recognition and classification of multiple gestures through machine learning algorithms while also exhibiting significant potential for inflammation hyperthermia therapy.
文摘Flexible wearable electronics have garnered substantial attention as promising alternatives to traditional rigid metallic conductors,particularly for personal health monitoring and bioinspired skin applications.However,these technologies face persistent challenges,including low sensitivity,limited mechanical strength,and difficulty in capturing weak signals.To address these issues,this study developed a hierarchical sandwich-structured piezoresistive foam sensor using phase inversion and NaCl sacrificial templating methods.The sensor exhibits an exceptional sensitivity of up to 83.4 kPa⁻1 under an ultralow detection pressure of 2.43 Pa.By optimizing the foam porosity,its mechanical performance was significantly enhanced,reaching a tensile fracture elongation of 257.3%at 73.42%porosity.The hierarchical sandwich structure provided mechanical buffering and layer-enhancement functionalities for dynamic responses,whereas the nanostructure further refined signal acquisition and interference resistance.Signal analysis using discrete wavelet transform(DWT)and continuous wavelet transform(CWT)enables multiscale and multifrequency characterization of arterial resistance signals under varying applied pressures.These findings underscore the sensor’s ability to capture weak signals and analyze complex pulse dynamics.This advancement paves the way for the extensive application of multifunctional sensors in smart devices and health care.This method offers a robust scientific basis for further understanding and quantifying arterial pulse characteristics.
