Piezo-ionic actuator for haptic feedback

Abstract

Electroactive polymers have received substantial attention for actuation because of their muscle-like actuation behaviour. These polymers are typically studied under ionic and electric classes based on their fundamental response mechanisms. In this study, a hybrid piezo-ionic actuator is developed and characterised by its electromechanical response to analyse the piezo-ionic synergistic effect in a cantilever beam actuation design. The piezo-ionic actuator was developed using polyvinylidene fluoride (PVDF) combined with an [Pmim][TFSI] ionic liquid (IL) filler. The addition of IL into the PVDF network promotes the formation of electroactive phases (β and γ), consequently enhancing the electromechanical response of PVDF while maintaining the characteristic fast response time of piezo materials. The IL also plasticize the PVDF polymer and increases its conductivity which also causes the electrical parameters to vary with frequency. It results in higher dielectric loss, energy storage and hysteresis in PVDF/IL responses. To evaluate the actuator performance, the force generated by the hybrid actuator is measured and a finger sleeve is designed for haptic feedback analysis.