Recent progress in the development of dielectric elastomer materials and their multilayer actuators

Dielectric elastomers (DEs) have emerged as one of the most promising artificial muscle technologies, due to their exceptional properties such as large actuation strain, fast response, high energy density, and flexible processibility for various configurations. Over the past two decades, researchers have been working on developing DE materials with improved properties and exploring innovative applications of dielectric elastomer actuators (DEAs). This review article focuses on two main topics: recent material innovation of DEs and development of multilayer stacking processes for DEAs, which are important to promoting commercialization of DEs. It begins by explaining the working principle of a DEA. Then, recently developed strategies for preparing new DE materials are introduced, including reducing mechanical stiffness, increasing dielectric permittivity, suppressing viscoelasticity loss, and mitigating electromechanical instability without pre-stretching. In the next section, different multilayer stacking methods for fabricating multilayer DEAs are discussed, including conventional dry stacking, wet stacking, a novel dry stacking method, and micro-fabrication-enabled stacking techniques. This review provides a comprehensive and up-to-date overview of recent developments in high-performance DE materials and multilayer stacking methods. It highlights the progress made in the field and also discusses potential future directions for further advancements. 介电弹性体(DE)具有驱动应变大、 响应快、 能量密度高、 可灵活处理各种配置等特点, 已成为最具前景的人工肌肉技术之一. 在过去的二十年中, 研究人员一直致力于开发性能改善的DE材料, 并探索介电弹性体驱动器(DEA)的创新应用. 本文重点讨论了两大主题: 介电弹性体的材料创新和介电弹性体驱动器多层堆叠工艺的发展, 这对推动介电弹性体的商业化应用具有重要意义. 本文对高性能介电弹性体材料和多层堆叠方法的最新进展进行了综述, 强调了在该领域取得的进展, 并讨论了未来潜在的研究方向. 在广泛的商业应用之前, DE仍有几个问题需要解决. 第一, 设计能够在高驱动频率(100 Hz量级)下保持大而稳定驱动应变(超过100%)的DE材料. 第二, 解决DE和DEA长时间使用的稳定性. 为了提高寿命, 应仔细研究失效机理, 并根据机理适当调整DE材料的介电性能. 第三, 需要开发具有高环境耐受性的DE材料. 最后, 需要解决高电压驱动导致的安全问题. 叠层DE驱动器(MDEA)的开发与DE的材料创新同样重要, 但MDEA的制备仍存在许多挑战. 适用于超薄DE薄膜堆叠的叠层工艺需要被探索. 此外, 提高当前叠层方法的扩展性也很重要, 以兼容大规模制造工艺.