Dielectric elastomer actuators
Dielectric elastomer actuators
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DOI：
10.1063/5.0043959
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发表时间：
2021-04-21
影响因子：
3.2
通讯作者：
Clarke, David R.
中科院分区：
文献类型：
--
作者：
Hajiesmaili, Ehsan;Clarke, David R.
介电弹性体致动器（dea）是一种软的电动致动器，没有分立的运动部件，但可以表现出大应变（10%-50%）和中等应力（类似于100kPa）。本教程描述了DEA操作的物理基础，从简单的线性分析开始，然后是描述执行器大应变特性所需的非线性牛顿和能量方法。这些导致了致动应变和有用的非量纲参数的理论限制，如归一化电击穿场。分析指导了弹性体材料和柔性电极的选择。由于dea在高电场下工作，本教程介绍了影响介电击穿威布尔分布的一些因素，几何效应，区分永久和“软”击穿，以及“自清除”及其与证明测试的关系，以提高器件的可靠性。在电场作用下分子排列的新证据也被提出。在柔顺电极的讨论中，碳纳米管（CNT）电极的基本原理是基于其柔顺性和即使在拉伸时也能保持其渗透电导率的能力。为那些希望自己制造碳纳米管电极的人提供了投诉程序。渗透电极不可避免地只产生部分表面覆盖，并介绍了对致动器性能的影响。描述了致动器几何的发展，包括最近的3D打印。介绍了多用途可重构变形执行机构的物理基础，并对其进行了分析，并用实例进行了说明。最后，将讨论实现更高性能dea的前景。
Dielectric elastomer actuators (DEAs) are soft, electrically powered actuators that have no discrete moving parts, yet can exhibit large strains (10%-50%) and moderate stress (similar to 100kPa). This Tutorial describes the physical basis underlying the operation of DEA's, starting with a simple linear analysis, followed by nonlinear Newtonian and energy approaches necessary to describe large strain characteristics of actuators. These lead to theoretical limits on actuation strains and useful non-dimensional parameters, such as the normalized electric breakdown field. The analyses guide the selection of elastomer materials and compliant electrodes for DEAs. As DEAs operate at high electric fields, this Tutorial describes some of the factors affecting the Weibull distribution of dielectric breakdown, geometrical effects, distinguishing between permanent and "soft" breakdown, as well as "self-clearing" and its relation to proof testing to increase device reliability. New evidence for molecular alignment under an electric field is also presented. In the discussion of compliant electrodes, the rationale for carbon nanotube (CNT) electrodes is presented based on their compliance and ability to maintain their percolative conductivity even when stretched. A procedure for making complaint CNT electrodes is included for those who wish to fabricate their own. Percolative electrodes inevitably give rise to only partial surface coverage and the consequences on actuator performance are introduced. Developments in actuator geometry, including recent 3D printing, are described. The physical basis of versatile and reconfigurable shape-changing actuators, together with their analysis, is presented and illustrated with examples. Finally, prospects for achieving even higher performance DEAs will be discussed.