皮肤-电极界面的传感性能及应用

柔性压力传感器由于其可弯曲、折叠、拉伸、小巧轻便等优势，在可穿戴设备、智能机器人等领域具有巨大的应用前景。目前大部分柔性压力传感器采用三层结构设计，传感器中最重要的活性层（例如离电型压力传感器中的离子凝胶）往往需要经过复杂的设计、合成、制备过程，同时有的活性层需要与外界环境隔离以保持其性能稳定。

人体皮肤组织本身就是天然的离子活性材料，含有大量的Na⁺、Cl^-、K⁺等离子。本文采用人体皮肤作为离电型压力传感器中的活性层，通过在皮肤表面贴附两个电极（有微结构的传感电极，以及没有微结构的对电极），构成皮肤电极压力传感结构（SEMS）。SEMS中，皮肤-电极界面形成电荷间距在纳米级别的双电层，通过电极与皮肤接触面积的变化，改变双电层界面面积和电容值，实现对表皮压力的传感。本研究将高长径比的柱状微结构引入传感电极，使SEMS具有灵敏度高（11.8 kPa^-1）、响应速度快（~15 ms）、检测限低（~0.2 Pa）、稳定性好（可承受5000次循环加载/卸载）等特点，同时具有良好的抗干扰和抗汗性能。基于此传感原理而开发的智能手套能够完成对使用者脉搏信号和触觉信号的实时检测，且在长期佩戴中受汗液影响较小。此外，本研究进一步提出并设计的自粘附皮肤-电极压力传感结构可嵌合到皮肤纹理中，达成更加稳定的接触界面和更好的使用体验。

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