The Role of Macroscopic Defects on Electromechanical Instability in Elastomer Dielectrics and Strategies for Mitigation

宏观缺陷对弹性体电介质机电不稳定性的作用及缓解策略

• 批准号: 2301509
• 负责人: Alex Chortos
• 金额: $ 32.56万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2301509&HistoricalAwards=false
• 关键词: Role; Macroscopic; Defects; Electromechanical; Instability

Polymer-based actuators provide new opportunities for emerging fields such as human machine interfaces due to their low cost and mechanical flexibility. Electrical actuation of soft elastomer achieves fast deformation, but the mechanism is limited by susceptibility to defects that can cause elastomer structures to fail prematurely. This award supports fundamental research into the role of defects in electrical actuation of elastomers (i.e, elastomer dielectrics) and explores mechanisms to overcome the negative impact of defects. The insights from this work could enable the adoption of low-cost polymer actuators for applications in medical devices, consumer electronics, and national defense, thus contributing to the benefit of society. The interdisciplinary nature of the work, spanning materials properties, mechanics of structures, and electronic properties, provides training opportunities for students in an emerging high-tech field. The award includes activities that leverage excitement about 3D printing and soft robotics to recruit students towards research. At the high school level, the award supports a course on 3D printing that includes content on the mechanics of polymers and their impact on the strength of structures. At the undergraduate level, a soft robotics club offers students the opportunity to get hands-on experience with the effect of polymer mechanics on robot performance.Electromechanical instability has been characterized for idealized elastomer dielectrics in a wide range of geometries. However, in manufactured systems, defects can reduce the critical electric field, which leads to the onset of instability, limiting the capability of the structure. The electromechanical deformation of many defects cannot be modeled analytically, motivating the use of a finite element approach. In this research, a finite element model will be validated through experimental monitoring of the electrically induced deformation in single-layer dielectrics with controlled sizes of defects. These devices will consist of silicone dielectrics to minimize non-idealities associated with viscoelasticity and dielectric dispersion. Finite element modeling over a range of defect sizes and geometries will provide computationally derived trends in the free energy associated with defects as a function of the defect size, geometry, and constitutive model of the elastomer. Multilayer dielectrics will be modeled to determine the influence of defects within one component of mechanically coupled structures. The introduction of discontinuous stiff electrodes in multilayer dielectrics will be investigated computationally and experimentally as a method to mitigate the effect of defects. Knowledge gained in this work will provide insights into the role of defects in field-coupled deformable structures.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

基于聚合物的致动器由于其低成本和机械灵活性而为诸如人机界面的新兴领域提供了新的机会。软弹性体的电致动实现了快速变形，但是该机制受到对可能导致弹性体结构过早失效的缺陷的敏感性的限制。该奖项支持对缺陷在弹性体电致动中的作用进行基础研究，并探索克服缺陷负面影响的机制。这项工作的见解可以使低成本聚合物致动器在医疗设备，消费电子和国防中的应用成为可能，从而为社会利益做出贡献。这项工作的跨学科性质，跨越材料性能，结构力学和电子性能，为学生提供了新兴高科技领域的培训机会。该奖项包括利用对3D打印和软机器人技术的兴奋来招募学生进行研究的活动。在高中阶段，该奖项支持3D打印课程，其中包括聚合物力学及其对结构强度的影响。在本科阶段，软机器人俱乐部为学生提供了获得实践经验的机会，与聚合物力学对机器人性能的影响。机电不稳定性已被表征为理想化的弹性体在广泛的几何形状。然而，在制造的系统中，缺陷可以降低临界电场，这导致不稳定性的开始，限制了结构的能力。许多缺陷的机电变形不能被建模分析，激励使用有限元方法。在这项研究中，有限元模型将通过实验监测的电致变形的单层缺陷的控制尺寸进行验证。这些器械将由硅橡胶组成，以最大限度地减少与粘弹性和介电分散相关的非理想性。在一系列缺陷尺寸和几何形状上的有限元建模将提供与缺陷相关的自由能的计算导出趋势，作为弹性体的缺陷尺寸、几何形状和本构模型的函数。将对多层结构进行建模，以确定机械耦合结构的一个组件内的缺陷的影响。本文将从计算和实验两方面研究在多层膜中引入不连续刚性电极以减轻缺陷的影响。在这项工作中获得的知识将提供现场耦合变形结构中缺陷的作用的见解。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。