Fortifying performance of soft actuator using hetero-space charge characteristics of PVC-gel & dielectric liquid

Abstract

A novel soft actuator design is presented in this paper. The actuator termed ‘EPIC’ utilizes the amplified electrostatic force when the surface charge inducing phenomenon of PVC-gel and the special geometry of the actuator are combined. Based on the principle, this novel actuator can exert large force at low operating voltage compared to the actuator utilizing only electrostatic force between electrodes. This suggests a new possibility to solve the high input driving voltage and limited output force issues of the dielectric electro-active polymer actuator (EAP). Also, the theoretical modeling of this actuator suggests new design criteria (dielectric constant ratio) for designing similar kinds of hydraulic actuators based on electrostatic force. Consequently, the designed prototype of the actuator could exert force larger than 4N and maximum displacement of 2mm despite their small size and weight(60mm width, 8.5 height and 25.5g weight including frame), without additional design optimization. Also, a focal length tunable lens was implemented as an application. The fabricated EPIC tunable lens has circular visible area, as large as 30mm diameter, and 178mm focal length change based on the high output force of the actuator.