柔性离子液体凝胶驱动的介电弹性体高频振荡器力电耦合行为

Dielectric elastomer(DE), as one of the electro-active polymers, has attracted increasing attention in recent years. Diverse potential applications of DE include soft robotics, actuators and sensors, energy harvesters, and morphing aircrafts. Conventional DE devices use electronic conductors, including carbon-based or nano-materials based grease or solid electrodes, and metal electrodes, with limitation on stretchability,transparency or system assembly. The recently reported stretchable and transparent hydrogel iononic conductors pave the way for development of DE devices. The volatility of water solvent, however, dramatically limits its lifetime. We for the first time propose to synthesize flexible, stretchable, transparent, nonvolatile ionogels as ionic conductors for the development of high frequency oscillator working at frequency beyond 20kHz. Finite element method in combination with incremental harmonic balance method is proposed to calculate the low and mid frequency vibration of oscillators, and energy finite element method is adopted to evaluate the high frequency response. The simulation results are compared with experimental results for validation. We will study several factors, such as geometrical parameters of oscillator, mass and stiffness of conductor, prestretch, and the vibro-acoustic coupling of oscillator and air, to probe the electro-mechanical behaviors and failure mechanism of the oscillator. The results will provide novel material realization, model, analysis method, and techniques for the design, fabrication, and failure prediction of electro-active polymer based soft machines.

介电弹性体(DE)是近年来倍受关注的一种电活性聚合物，在柔性机器人、驱动器及传感器、能量收集器、变体飞行器等领域有重要应用前景。传统DE器件采用电子导体来驱动，主要包括含碳颗粒、纳米材料等导电元素的膏状或固体电极以及金属电极，在延展性、透明性或系统集成方面存在缺陷。最近报道的柔性、透明水凝胶离子导体，为DE器件研制开辟了新思路，但水的挥发性限制了器件的寿命。项目首次提出制备低模量、高拉伸比、透明、不挥发的离子液体凝胶为离子导体，研制20kHz高频振荡器。提出采用有限元和增量谐波平衡法联合求解中低频振动，能量有限元法求解高频振动，并和实验测试结果互相对比印证。研究振荡器几何参数、导体质量和刚度、预拉伸以及振荡器与空气的声振耦合等因素对振荡器力电耦合行为的影响，揭示高频振荡器的失效机理。本项目的研究成果将为电活性聚合物软机械的设计、研制和失效预测提供新的材料实现、理论模型、分析方法和技术手段。

介电弹性体是一种新型电活性聚合物，在驱动器、俘能器、可穿戴电子等领域有广泛的应用前景。传统的介电弹性体采用的是流体状的碳膏电极或其他固体电子导体电极。项目丰富发展了离子导体驱动介电弹性体柔性器件的设计原理和实现方案，在低模量、高拉伸比、透明、不挥发离子凝胶导体的制备，离子凝胶导体驱动的介电弹性体驱动器及振荡器的力电耦合行为，离子导体驱动介电弹性体软机械设计、制备、实验验证和力电耦合数值模拟方法等方面取得重要进展。在项目执行过程中，在Adv. Mater.等国际重要期刊发表学术论文23篇，出版专著1部，参加国内外学术会议并做邀请报告9次，培养博士生3名，硕士生2名。项目研究成果为柔性导线、可调光学、高频振荡器以及软机器的设计和实现提供了新思路和新方法。