基于 PVDF-HFP 的高灵敏度高线性度柔性电容式压力传感器设计

       随着全球老龄化的加剧和物质生活水平的提高，人们越来越关注自身 的健康状况。然而，现有的医疗系统和设备难以为每个人提供及时有效的 医疗服务。因此，构建微小、便携的健康监测器件，以实现精准、实时的 健康监测人体生理信号，成为备受关注的技术问题。由于人体生理活动， 如呼吸、心跳、说话和运动等都会产生人体界面压力的变化，因此使用可 贴合人体皮肤、响应速度快的便携式柔性压力传感器可以精确采集多种人 体生理信号，实现对人体的精准、实时、连续长时程的健康监测。

       本文从电容式压力传感器的内部结构出发，通过在电极层中引入微结 构，建立传感器灵敏度等性能与微结构空间复杂度关系模型，研究影响电 容传感器性能的物理学效应与机制。首先，选用杨氏模量较小的聚二甲基 硅氧烷（Polydimethylsiloxane，PDMS）作为基底材料。接着，首次提出使 用朱槿花天然材料作为微结构模板，通过正反两次倒模得到了具有乳突状 的 PDMS 基底材料。为提高传感器灵敏度，介电层材料选用了具有压电特 性的聚偏氟乙烯-六氟丙烯（Polyvinylidene fluoride-hexafluoropropylene， PVDF-HFP）离子凝胶膜。通过激光切割制备图案化掩模版，放在具有微结 构和表面平滑的 PDMS 上，随后均匀喷涂银纳米线，分别用作上下电极层 材料。对制备的柔性压力传感器进行了性能分析，结果显示在 2.5-5 kPa 的 压力范围内，灵敏度高达 42.35 kPa^-1，且其在 0-15 kPa 的压力范围内总体 线性度高达 98.18%。该传感器的快速响应时间和恢复时间均为 61.5 ms，通 过 3000 次重复性测试且误差较小，表面出良好的耐久度与稳定性，并在检 测微弱压力应用方面具有一定潜力，可以对玉米粒、绿豆等微小颗粒做出 响应。此外，该传感器在人体脉搏、呼吸以及声带振动监测等方面表现出 良好的可应用性，显示了在人体健康和运动状态监测及电子皮肤等柔性可 穿戴器件中巨大的应用潜力。

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