Active tensegrity structures using electrostatic actuators

Abstract

Tensegrity structures have been applied to soft robots because of their light weight, mechanical stability, and flexibility. Many tensegrity robots developed in other research have been driven by motors. However, there are concerns that the use of motors may lead to problems such as increased weight, increased structural complexity, and reduced flexibility. In this study, we propose the integration of a type of smart material, hydraulically amplified self-healing electrostatic actuators (HASEL actuators), into tensegrity structures. The use of HASEL actuators as cables for tensegrity is expected to simplify the structure, reduce weight, and improve flexibility. In this paper, we fabricated and characterized a tensegrity structure consisting of three rods and four HASEL actuators to demonstrate the proof-of-concept of a tensegrity structure integrating HASEL actuators. OPP film was used for the shell, Fluorinert (FC40, 3M) was used for the liquid dielectric, and conductive double-sided tape (CN4490, 3M) was used for the electrodes of HASEL actuators. The rods were fabricated by a 3D printer (Form3, Formlabs). Four Hasel actuators were subjected to a voltage and the change in tensegrity structure was determined. It was confirmed that the higher the applied voltage, the smaller the tensegrity structure. The experimental results indicate that the tensegrity structure integrated with the HASEL actuators is actuated, and the concept proposed in this study is proven. Further analysis of the characteristics and optimization of the tensegrity structure will be the focus of future work.