Liu Xuejing, Xing Yu, Sun Wenjie, Zhang Zhouqiang, Guan Shengqi, Li Bo
College of Mechanical and Electrical Engineering, Xi'an Polytechnic University, Xi'an, China.
School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, China.
Front Robot AI. 2021 Apr 21;8:672154. doi: 10.3389/frobt.2021.672154. eCollection 2021.
The dielectric elastomer (DE) is a new kind of functional polymer that can be used as a smart actuator due to the large deformation induced by voltage excitation. Dielectric elastomer actuators (DEAs) are usually excited by dynamic voltages to generate alternating motions. DEAs are prone to premature breakdown failure during the dynamic excitation, while the research on the breakdown of DEAs under cyclic voltage excitation is still not fully revealed. In this paper, the dynamic breakdown behaviors of DEAs made from VHB4910 film were experimentally investigated. The factors affecting the breakdown behavior of DEAs under dynamic voltages were determined, and the relevant changing laws were summarized accordingly. The experimental results show that under dynamic voltage excitation, the critical breakdown voltage of DEAs were augmented slowly with voltage frequency and showed a substantial dispersion. In addition, the maximum cycle numbers before breakdown were significantly affected by voltage parameters (such as frequency, amplitude, waveform). Finally, the underlying mechanisms of breakdown under cyclic voltages were discussed qualitatively, a power-law equation was proposed to characterize the maximum cycle number for the dynamic breakdown of DEAs, and related parameters were fitted. This study provides a new path to predict the service life of DEAs under dynamic voltage.
介电弹性体（DE）是一种新型功能聚合物，由于电压激励会引起大变形，它可被用作智能致动器。介电弹性体致动器（DEA）通常由动态电压激励以产生交变运动。DEA在动态激励过程中容易出现过早击穿失效，而关于DEA在循环电压激励下击穿的研究仍未完全揭示。本文对由VHB4910薄膜制成的DEA的动态击穿行为进行了实验研究。确定了影响DEA在动态电压下击穿行为的因素，并据此总结了相关变化规律。实验结果表明，在动态电压激励下，DEA的临界击穿电压随电压频率缓慢增大且呈现出较大的离散性。此外，击穿前的最大循环次数受电压参数（如频率、幅度、波形）的显著影响。最后，定性地讨论了循环电压下的击穿潜在机制，提出了一个幂律方程来表征DEA动态击穿的最大循环次数，并对相关参数进行了拟合。本研究为预测DEA在动态电压下的使用寿命提供了一条新途径。
