基于三维导电网络的压力传感器制备及性能研究

  近年来，柔性压力传感器作为核心部件之一在植入式电子设备、电子皮肤和可穿戴式健康监测设备等领域展现出巨大的应用潜力。目前，基于电阻式柔性压力传感器的研究主要集中于通过优化敏感材料性能及提出新颖的结构设计来对电阻式压力传感器性能进行提升。本论文提出银纳米线（AgNWs）三维编织态导电网络作为器件的导电功能层，并引入一种刚性力学传导结构，提升柔性电阻式压力传感器的灵敏度等性能。主要研究结果如下：
为实现三维编织态银纳米导电网络与后期的刚性微球铺陈与封装工艺的兼容性，提出了聚二甲基硅氧烷（PDMS）软光刻工艺，将硬质硅基底的倒四棱锥腔阵列复刻到柔性基体上，避免三维导电网络在转移过程中造成的损伤，同时实现了器件结构调控的可行性。此外，实现了三维编织态AgNWs导电网络在PDMS上的可控沉积。并研究了AgNWs墨水在PDMS模板微腔体中的流体自组装行为。

将刚性氧化锆（ZrO2）微球引入到上述压力传感器中，在不破坏下层三维导电层的前提下将刚性微球阵列成功铺陈到PDMS微腔体中，并利用PDMS浇筑实现了微球阵列的定位和封装。通过将低杨氏模量微结构PDMS弹性体和高杨氏模量ZrO2微球组装在一起，并采用三维AgNWs导电网络作为功能层，制备柔性压力传感器。测试结果显示，引入刚性微球后，压力传感器的灵敏度提升了10倍。分析该刚性微球可在局部区域形成应力集中，将外加压力高效地定向传递到导电功能层，从而提高了器件的性能。采用有限元仿真对刚性微球作用下器件的应力应变进行了评估，从理论角度验证了刚性微球的力传导机理。

本文从器件结构设计、三维编织态导电层自组装行为、刚性微球的力传导机制等对器件的性能影响出发，提出了一种基于三维编织态AgNWs导电网络及刚性微球耦合的柔性压力传感器，对新型高灵敏性压阻式压力传感器的结构设计、制备和性能提升有一定的工程价值和指导意义。

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