Soft dielectric elastomer actuator for micropump application

Abstract

This paper reports a miniaturized soft dielectric elastomer actuator targeted at an active flow controlled application. The muscle-alike soft actuator buckles when subjected to a pre-stretch tensile force by a pull up spring that is made from 2 mm thick elastic plastic. The actuator forms an out-of-plane deflection in a conical frustum shape profile and couples with a pair of diffuser elements to rectify the fluid flow in a contraction and expansion mode. To achieve desired deflection, finite element analysis is deployed to study the geometrical design of the elastomer parameters. A maximum deflection of 0.42 mm is noted at 4.2 kV, where beyond this voltage, wrinkle is formed on the compliant electrode. The deflection dynamic response of each repetitive actuation cycle achieves high reliability at low operating frequency of 0.1 Hz and 0.25 Hz with the standard deviation of 1.4% and 1.25%, respectively. The frequency dependent characteristic of the device is determined by measuring the effective deflection at each frequency cycle. Experimental characterization of the fabricated micropump shows a successful maximum flow rate of 42 μL/s at an optimum frequency of 3 Hz.