Rigid electrodes enhance the strain and force output of Peano-HASEL actuators

Abstract

Peano-HASEL (hydraulic amplified self-healing electrostatic) actuators represent a recent advancement in the field of muscle-like soft actuators. They typically consist of flexible electrodes, a flexible and inextensible shell, and liquid dielectric. However, Peano-HASEL actuators employing flexible electrodes can only utilize the electrostatic force generated by a limited area of electrodes to maintain compression of the liquid, resulting in a restricted strain and force outputs. In this Letter, we show that a Peano-HASEL actuator employing rigid electrodes exhibits a significantly enhanced strain and force output. Compared to the conventional flexible-electrode Peano-HASEL actuator, the actuator with rigid electrodes demonstrates a remarkable improvement, with a more than 200% increase in strain output and a more than 140% increase in force output. Notably, we successfully showcase the capability of a Peano-HASEL actuator with rigid electrodes to reliably lift a 50 g load at an 8 kV voltage, a task that the counterpart with flexible electrodes of the same electrode length, width, and oil volume fails to accomplish. This highlights the great potential of rigid-electrode Peano-HASEL actuators for applications such as robotic manipulation.