基于核-壳结构设计的柔性触觉传感器及其应用研究

Flexible tactile sensor is one of the key technologies in flexible wearable electronics and intelligent robots. It is of great significance for realizing human health monitoring and human/machine friendly interaction. However, traditional flexible tactile sensors still have shortcomings in device construction, sensing sensitivity, mechanical stability under high stress, long-term wear comfort, etc. It is challenging to fabricate sensors with highly sensitive, fast response, stable sensing under high pressure and long-term comfort abilities. In this project, we design an ionic activated material with core-shell structure. The pore skeleton of porous polymer material(core structure), as a mechanical support layer, offers a stable mechanical deformation, and ionic gel active layer on the surface of the pore skeleton(shell structure) constructs electronic double layer interface to provide capacitive sensing function. Such capacitive sensors is expected to achieve high sensitivity, stable sensing under high pressure, and comfortable wearing functions such as ventilation and perspiration. The project aims to establish the relation between the reaction process of the ion gel activated layer and the sensing performance by regulating the preparation process of the active material of the core-shell structure. Moreover, the activation process can be applied to the large-area porous substrate to achieve activated layer in desired area for sensing, which helps to develop a new way to prepare smart sensing cloth with high sensitivity and comfort long-term wearablity.

柔性触觉传感器是柔性可穿戴电子、智能机器人中核心技术之一，对实现人体健康监测及评估、人/机友好交互具有重要意义。然而，常规柔性触觉传感器在器件的构筑、传感灵敏度、高应力下的力学稳定性、长期穿戴舒适性等方面仍存在不足，制备高灵敏、快响应、大压力下稳定传感并且可长期舒适穿戴的传感器颇具挑战。本项目根据“核-壳结构”材料的设计思路，以高分子多孔材料的孔骨架为力学支撑层，提供稳定的力学变形，通过在孔骨架表面构筑离子凝胶活性层，构筑多孔的离子型电容式传感器，达到高灵敏、高压下稳定传感，并兼顾透气、排汗等舒适穿戴功能。项目将通过调控“核-壳结构”活性材料的制备工艺，建立离子凝胶活性层的反应工艺与器件传感性能之间的关联，并将活化工艺拓展到大面积多孔基底上，实现局部的区域传感，为制备高灵敏、可长期舒适穿戴的智能传感服装提供新途径。

柔性压力传感器是可穿戴柔性电子、智能机器人中的核心技术之一，对实现人体健康监测及评估、人/机友好交互具有重要意义。然而，柔性压力传感器往往需引入有微结构的离子软材料来提升灵敏度，并且以多层简单堆叠封装而成，这导致了多层、多材结构界面兼容性问题，严重影响其在复杂受力下的长期服役稳定性。制备既具有高灵敏、又满足复杂工况下长期服役稳定的柔性压力传感器颇具挑战。本项目选取力学响应灵敏的高分子多孔材料和纤维为力学骨架，通过引入稳定粘附的离子凝胶层，构建了“核-壳结构”高灵敏传感介电层。随后利用溶剂浸润法对高分子聚集态结构重排，实现了导电层和介电层的粘附一体化制备，解决了多层、多材传感结构的界面兼容问题。结果表明基于“核-壳结构”设计的多孔聚氨酯基柔性压力传感器在0-300kPa压力范围内具有较高灵敏度（16.25kPa-1），同时具有较高的耐疲劳性，同时具备透气、抗菌性能，在人体长期可穿戴领域具有潜在应用价值；进一步的，基于气流纺丝工艺制备的聚酰亚胺基纤维层叠一体式柔性压力传感器，导电-介电粘附界面韧性界面韧性高达120 Jm-2，在0-4000kPa的超宽检测范围能保持高灵敏传感，低压区灵敏度可达156.6kPa-1。融合界面使得器件在1970kPa压力、437kPa剪切力作用下循环10,000次无疲劳。阵列化集成的柔性智能足底压力传感系统可实现高精度足底压力分布的检测及步态分析，并在跑步等复杂工况下稳定传感。此外，基于全PDMS材质的一体式粘合封装的柔性压力传感器，在如汽车碾压极端工况下，仍能够表现出优异的稳定传感功能。“同质”设计及多层界面的粘附可从根本上解决不同材料体系导致的界面兼容性差和力学失配问题，达到材料-材料的共融设计，本项目研究结果对后续电子皮肤在智能制造、健康监测等领域中复杂受力模式下的可靠稳定传感功能的构筑提供了新方法。