Lowering the voltage of dielectric elastomer actuators (DEA) for wearables

Abstract

Dielectric elastomer actuators (DEAs) often require the use of high voltage for its operation. In the application of DEAs for wearables, it is important to avoid the use of high voltage for safety purposes. Thus, there is a need to further reduce the voltage for the operation of DEAs. The aim of this project is to synthesize polyurethane acrylate (PUA) DEA functionalize with a fluorine group (CF), trifluoroethyl acrylate (TFEA), in order to increase the dielectric constant for higher performances at lower voltages. Fluoroelastomers have very high dielectric constants and display hydrophobic properties. Hydrophobic properties can expand the stability of DEAs especially for wearables that may be exposed to environments with moisture.

In this report, a dielectric elastomer actuator (DEA) is designed through free radical polymerization between polyurethane acrylate (PUA) and trifluoroethyl acrylate (TFEA). The introduction of polar CF groups will increase the dielectric constant to achieve higher performances at lower voltages. The fluorine atoms further lower the surface free energy of the elastomer which causes them to be hydrophobic. By combining high actuation performance at lower electric fields and imparting hydrophobic properties to DEAs, these actuators can achieve higher stability and be better suited for wearables that may be exposed to environments with moisture.