1成果简介

　　柔性传感器在智能可穿戴设备、电子皮肤和健康监测领域展现出巨大应用潜力。然而，采用简单且经济高效的制备方法开发具有宽感知范围和高灵敏度的高性能传感器仍面临挑战。有别于仅能检测应变的传统单功能传感器，本文，上海电机学院曹胜彬 教授团队在《 ‌Mater Des》期刊发表名为“Graphene/MXene modified polyurethane flexible nanomembrane for dual-functional pressure-temperature sensing”的论文，研究基于电纺纳米纤维平台开发了一种柔性可穿戴压力-温度双功能传感器。通过将石墨烯/MXene复合溶液喷涂于聚氨酯（PU）纳米纤维膜上，制备出电阻式压力传感器。
　　同时，通过将石墨烯/MXene与聚（3,4-乙烯二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT:PSS）结合，将电阻式温度传感器与压力传感器集成，形成双功能传感器。制备的传感器展现出超高灵敏度（GF≈1200）、快速响应时间（110毫秒）、高耐久性及稳定性能，经5000次运动循环后仍无性能衰减。该双功能传感器可实现1℃分辨率的精准温度检测。在实际应用中，该传感器可舒适佩戴于手腕，能够实时监测脉搏跳动等细微应变变化、手指弯曲等大幅应变变化，以及体温波动等温度变化。
　　2图文导读 

　　图1. Schematic diagrams for preparing (a) polyurethane nanofiber film, (b) pressure-sensitive sensing layer, (c) temperature sensing layer and overall assembly of sensor and (d) applications of sensor.

　　图2. Photographs of the PU nanofiber film (a) before and (b) after being treated with composite suspension (top to bottom stretched by 25%, 45% and 75%, respectively), SEM images of PU fiber film (c) without and (d) with composite suspension treatment, (e) SEM-EDS mapping images of the treated PU nanofiber film.

　　图3. Analysis of MXene/GR-PU composite: (a) Infrared Fourier transform infrared (FTIR) spectrum, (b) powder XRD patterns and (c) Raman spectrum.

　　图4. (a) Schematic on sensing mechanism of dual-functional pressure–temperature sensor, (b-d) relative resistance change response under varied strains of 0–35 % measured at different temperatures of (b)15 °C, (c) 25 °C and (d) 35 °C, (e) combined plot of signals collected at different strains under varying temperatures.

　　图5. (a) Schematic setup for evaluating the permeability of different films and (c) corresponding the water vapor permeability chart, (b) PI film and PDMS film SEM, (d) Sensor performance testing setup, (e) I-V curve of the sensor under 0–40% stretching, (f) Relationship between sensor resistance change and strain, (g) diagram of temperature evaluation setup, (h) I-V curve of the sensor under different temperature gradients, (i) Variation of hotspot voltage with varied temperature ΔT.

　　图6. Pressure–temperature dual-functional sensor evaluations: (a) long-term stability, (b) relative resistance change response under varied strains and (c) different frequency response under 20 % stretching, (d) thermoelectric current with various strains under different temperature gradients, (e) tension recovery response pattern and (f) sensor thermal response curve at a temperature gradient ΔT = 1°C.

　　图7. Human body movements detection: (a) Pulse signal on wrist, (b-d) bending at (b) Knee, (c) index finger bending and (d) Elbow, (e) vibration at throat, (f) Mouse click, Hotspot voltage patterns (g) at different distances from the fire source and (h) at different temperatures, (i) Relative resistance output changes caused by skin temperature in different states.
　　3小结
　　一种压力-温度柔性双功能传感系统已成功研制，可同时实现对压力与温度信号的高性能检测。该传感系统的制备过程简便，易于集成，在实际应用中操作直观。得益于石墨烯与MXene的协同效应，系统压力传感单元展现出超高灵敏度（GF≈1200）、 毫秒级快速响应（上升时间≈110毫秒，下降时间≈130毫秒）、宽应变检测范围（0–50%）及优异的循环稳定性（经5000次加载卸载测试仍保持稳定性能）。同时，基于石墨烯、MXene及PEDOT:PSS的高热敏特性，该传感器对温度变化响应显著，可有效区分微小温差（低至1℃），实现不同热源的精准识别。在人体动作检测中，系统不仅能稳定捕捉大范围关节运动，更能精确感知脉搏、喉部震动等微弱生理信号。此外，该系统展现出精准区分各类温度场景的能力，彰显其在可穿戴健康监测与人机交互领域的广阔应用前景。
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