Exploiting the molecular and nano-structure engineering, electroactive polymers (EAPs) with giant electromechanical responses have been developed at Penn State. For the field actuated EAPs, a class of defects modified polar-fluoropolymers have been demonstrated to exhibit a high electrostrictive strain, a high energy conversion efficiency, and high elastic energy density (< 1 J/cm3), which has been commercialized by Akema and commercial actuator products have been developed at Novesentis. This talk will briefly review these results. In contrast, the ionic EAPs such as ionic polymer metal composites whose actuation mechanism is based on the excess ion accumulation/depletion at the electrodes, suffer low actuation strain, elastic energy density, and efficiency. On the other hand, the very low operation voltage, often below 5 volts, of i-EAPs is very attractive, compared with very high operation voltage of the field actuated EAPs. In the past several years, we have been investigating approaches to significantly enhance the electromechanical response of i-EAPs. This talk will present the recent works on a class of nano-structure engineered graphene nano-composites that exhibit a high strain response (< 50% strain) with an exceptionally high elastic energy density < 1.5 J/cm3, induced under low voltage (< 5 V) with a high efficiency. These results point out the potential of EAPs in achieving high performance by exploiting nano-structure engineering and their promise for advanced solid state actuator applications.
ACKNOWLEDGEMENT: The work was supported by NSF under Grant No. CMMI-1130437.