纤维基三明治夹芯结构电子皮肤的可控制备及动态压力传感机制研究

Nowadays the electronic skins for pulse monitoring widely exist the weaknesses of poor breathability and low sensitivity, easily causing the problem of skin irritation and the difficulties of data reading and analysis, which can hardly meet the urgent needs of high comfort and stability for long-term and real-time pulse monitoring. This project intends to study the formation and structure regulation of fiber based electronic skin, and reveal its dynamic pressure sensing mechanism, so as to obtain a highly sensitive and breathable electronic skin. Recently the applicants fabricated an all-fiber structured electronic skin using the electrospinning technique, which can sense the pressure change with decent permeability. However, the current pressure response accuracy is still not capable of fulfilling the requirement of practical application. This project will carry out the controllable preparation of laminated sandwich structured (namely orientation-porous-orientation) fiber materials and their piezoelectric properties optimization research, reveal the forming boundary condition and control rules of sandwich structured nanofibers, simulate the evolution process of charge formation and transfer on the surface of nanofibers, establish the suitable pressure response model for multilayered composite nanofibers, clarify the pressure sensing mechanism of fiber based electronic skin, illustrate the inner relation between the intrinsic structure of fiber based electronic skin and its application performance, realize the goals of sensitivity higher than 500 mV/kPa and linearity better than 0.1 %F.S. in the range of 10-100 kPa, in order to eventually meet the demand in the field of intelligent wearables.

当前脉搏监测用电子皮肤普遍存在不透气、灵敏度低等缺陷，易导致皮肤发炎、读数和分析困难等问题，难以满足长期实时监测对高舒适性和稳定性的迫切需求。本项目拟研究纤维基电子皮肤的成型及结构调控规律，揭示其动态压力传感机制，从而获得高灵敏度可呼吸电子皮肤。近期申请者利用静电纺丝技术制备出全纤维结构触觉传感型电子皮肤，其透气性优异，但现有压力响应精度仍未达到实际应用要求。本项目将开展三明治夹芯（取向-多孔-取向）结构纤维膜材料的可控制备及其压电性能优化研究，揭示三明治夹芯结构纳米纤维膜的成型边界条件及调控规律，模拟纤维膜表面电荷形成与转移的演变过程，建立适用于多层复合纤维结构的压力响应模型，阐明纤维基电子皮肤的压力传感机制，明晰纤维基电子皮肤本体结构与应用性能间的内在关联，实现在10-100kPa区间内灵敏度高于500mV/kPa，线性度优于0.1%F.S.的目标，以满足其在智能可穿戴领域的应用需求。

受生物皮肤的启发，电子皮肤作为一种新型的可穿戴系统具有仿皮肤触觉传感功能，并在多个领域具有广阔的应用前景，如人工假肢、智能机器人、可穿戴设备、健康监测等。依据其实际应用性能，除传感性能外，电子皮肤还必须具有良好的柔性、可拉伸性、轻量化、可呼吸性等基本性能。纤维和织物材料作为人体的第二“皮肤”与皮肤贴附性较好，具有柔软、透气、轻薄等独特优势，将其与可穿戴技术结合解决电子皮肤难以集成、不透气等问题具有重要意义。而静电纺丝技术能够直接制备微纳米纤维，具有设备简单、成本低廉、可连续生产等优势。本课题以纳米纤维膜为核心设计纤维基三明治夹芯结构电子皮肤，通过材料设计、纤维形貌调控及后处理工艺提升纤维膜的传感性能、透气性能及力学性能，并基于多种传感原理，对各个功能层实现集成设计，进一步赋予器件多功能的特性，以满足可穿戴电子器件更连续、灵敏的监测需求和复杂多变的使用环境。