柔性传感器在可穿戴电子设备中发挥着重要作用。这项研究通过制备一种兼具传感和电磁波吸收能力的聚氨酯泡沫,解决了材料不友好、制备工艺复杂和成本高等问题。采用一步发泡法制备了一种含有氧化还原石墨烯(rGO)的多功能木质素基聚氨酯泡沫(LPUF)。这种木质素基聚氨酯泡沫压阻传感器具有优异的性能,包括在 0～90%的宽压缩范围内具有出色的电阻变化性能,以及在循环600s内具有稳定的电阻变化。该传感器能够监测不同尺寸的变形,对不同频率(0.5Hz、0.2Hz、1Hz、2Hz)的外部刺激具有良好的响应性能,当前响应时间为0.19s。在 0～90%压缩变形的应变范围内,测量因子(GF)值分别为1.51、6.96和65.30。该传感器不仅能检测到人体肢体和关节的粗大运动,还能长时间检测到张口、吞咽、呼吸(呼吸频率为18次/min)和脉搏(脉搏频率为68次/min)等细微的生理活动,并且对所有活动大小都具有良好的重现性和可重复性。此外,这种泡沫还具有电磁辐射吸收特性,含石墨烯的木质素基聚氨酯泡沫(rGO@LPUF)在X波段的平均电磁干扰值为21dB。这种多功能泡沫的制备工艺简单、材料来源广泛、响应性能优异,并具有传感和电磁辐射吸收功能,因此在未来的柔性可穿戴电子设备和医疗保健应用中具有巨大潜力。
Flexible sensors play a vital role in wearable electronic devices.This work addressed the issues of unfriendly materials,complex preparation processes,and high costs by preparing a polyurethane foam with both sensing and electromagnetic wave absorbing capabilities.A multifunctional lignin-based polyurethane foam (LPUF) containing redox graphene (rGO) was prepared by the one-step foaming method.The lignin-based polyurethane foam piezoresistive sensor exhibited excellent properties,including an outstanding resistance change performance over a broad compression range of 0～90% and stable resistance change within 600s of cycling.The sensor demonstrated the ability to monitor deformation of different sizes and exhibited good response performance to external stimuli at different frequencies (0.5Hz,0.2Hz,1Hz,2Hz),with a current response time of 0.19s.The gauge factor (GF) values were determined as 1.51,6.96,and 65.30 within the strain range of 0% to 90% compression deformation.The sensor successfully detected not only gross movements of human limbs and joints but also subtle physiological activities such as mouth opening,swallowing,breathing (respiratory rate of 18/min),and pulse (pulse rate of 68/min) over extended periods with good reproducibility and repeatability for all activity sizes.Additionally,this foam exhibited electromagnetic radiation absorption properties,with graphene-containing lignin-based polyurethane foam (rGO@LPUF) demonstrating an average EMI value of 21dB in the X-band.Due to its simple preparation process,wide availability of materials,excellent response performance,and functionality in sensing and electromagnetic radiation absorption,this multifunctional foam holds significant potential for future flexible wearable electronic devices and healthcare applications.
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基金资助
国家重点研发计划项目(2017YFE0102300);宁波市重点研发计划项目(2022Z139);国家自然科学基金(U21B2093)
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