微米尺度表面结构对柔性电极界面电学特性的影响研究

As the contact area between finger and the forced object reduces from fingertip size to the micron-scale, the intensity of pressure on the contact area increases one hundred million fold at the same pressure due to the area decreases the same fold. On the basis of the microscale effect, the project will develop a flexible sensitive tactile sensor using new conductive polymers and the thin film electrode with the improved configuration through detecting the electrode capacitance or contact resistance. The detail ideas are as follows: (1) the flexible thin film electrodes are produced using silicone material and polythiophene with high electrical conductivity as the matrix and coating respectively. The soft silicone with space or surface micron-structural features including different shape, size and distribution density is added to the gap between the thin film electrodes and consequently compressed. Then the correlation between the capacitance and the structural shape and the compressive distance of the soft silicone filler is researched. (2) the flexible thin film electrode with the surface micron-structural features is produced by micro-structure processing on the surface of the soft silicone material and polythiophene coating with low electrical conductivity. The correlation between the contact resistance and the structural deformation and the contact area of the surface micro-structure with the different shape, size and distribution density is researched under the same condition as the former. The study aims to explore the effective way to improve the tactile sensor performance using the surface microscale effect, so as to provide technical support for the development of a new generation of artificial skin.

当手指与受力物体的接触面积从指尖大小缩小到微米尺度后，面积缩小约1亿倍，而相同压力下的压强却增大了相同的倍数。基于这种微尺度效应，本项目拟从新型导电聚合物的应用与改进薄膜电极结构两方面着手，分别以电极电容和接触电阻为检测量，研制柔性好、灵敏度高的触觉传感器。具体思路如下：（1）以柔性硅酮材料为基体，高电导率型聚噻吩为涂层，制作柔性薄膜电极。通过在电极间填充具有空间或表面微米结构特征的柔性硅酮材料，研究不同构型、尺寸、分布密度的填充物，在电极受压后的结构形态、压缩距离与电极电容间的关系；（2）在柔性硅酮材料表面进行微结构加工，以低电导率型聚噻吩作为覆盖层，制作表面具有微米结构特征的薄膜电极，进一步研究表面上不同构型、尺寸、分布密度的微结构受力后的结构变形、接触面积变化与接触电阻间的关系。本项目旨在探索利用表面微尺度效应提高触觉传感器性能的有效途径，为新一代人工皮肤的研制提供技术支持。

当前可穿戴设备和智能机器人已经成为消费电子产品和国民经济的主要发展方向，而柔性触觉传感器或多维力传感器正是其不可缺少的重要组成部分。本项目旨在探索利用表面微尺度效应提高触觉传感器性能的有效途径，为新一代人工皮肤的研制提供技术支持。本项目以柔性电容式压力传感器为主要研究对象，围绕柔性介电薄膜、表面微结构化、传感器叠层结构、传感器尺寸与电容响应关系、多维力解耦算法等方面开展研究。结果表明薄膜表面微结构化可显著提高柔性电容式压力传感器的灵敏度；而堆叠结构的应用对提高传感器信号输出有明显效果；含单层微结构化薄膜的敏感单元，其尺寸大小与信号响应并不存在单调增减关系，而是存在一个使灵明度最大化的最佳值；多维力解耦算法必须结合传感器结构特点才能达到提高精度降低解耦难度的目的。本项目证实了介电层薄膜表面微结构化是一种提高柔性电容式压力传感器性能的行之有效的方法，对于开发类似结构原理的传感器具有重要的参考价值。