Affiliation:
1. School of Mechanical and Electrical Engineering, Xi’an University of Architecture and Technology, Xi’an 710049, China
2. Department of Mechanical and Electrical Engineering, Yuncheng University, Yuncheng 044000, China
3. Research Centre for Medical Robotics and Minimally Invasive Surgical Devices, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences, Shenzhen 518055, China
Abstract
Inspired by the fact that flying insects improve their power conversion efficiency through resonance, many soft robots driven by dielectric elastomer actuators (DEAs) have achieved optimal performance via first-order modal resonance. Besides first-order resonance, DEAs contribute to multiple innovative functions such as pumps that can make sounds when using multimodal resonances. This study presents the multimodal resonance of a rectangular planar DEA (RPDEA) with a central mass bias. Using a combination of experiments and finite element modeling (FEM), it was discerned that under a prestretch of 1.0 × 1.1, the first-, second-, and third-order resonances corresponded to vertical vibration, rotation along the long axis, and rotation along the short axis, respectively. In first-order resonance, superharmonic, harmonic, and subharmonic responses were activated, while only harmonic and subharmonic responses were observed in the second- and third-order resonances. Further investigations revealed that prestretching tended to inhibit third-order resonance but could elevate the resonance frequencies of the first and second orders. Conveniently, both the experimental and FEM results showed that the frequencies and amplitudes of the multimodal resonances could be tuned by adjusting the amplitudes of the excitation signals, referring to the direct current (DC) amplitude and alternating current (AC) amplitude, respectively. Moreover, instead of linear vibration, we found another novel approach that used rotation vibration to drive a robot with soft bristles via hopping locomotion, showcasing a higher speed compared to the first-order resonance in our robot.
Funder
Key R&D Project in Shaanxi Province
Reference39 articles.
1. Soft Actuators for Soft Robotic Applications: A Review;Mishra;Adv. Intell. Syst.,2020
2. Shape Memory Alloy (SMA) Actuators: The Role of Material, Form, and Scaling Effects;Kim;Adv. Mater.,2023
3. A review of shape memory polymers and composites: Mechanisms, materials, and applications;Xia;Adv. Mater.,2021
4. Review of dielectric elastomer actuators and their applications in soft robots;Guo;Adv. Intell. Syst.,2021
5. Gu, G.Y., Zhu, J., Zhu, L.M., and Zhu, X. (2017). A survey on dielectric elastomer actuators for soft robots. Bioinspir. Biomim., 12.