Modification of Dielectric Elastomer with Ionic Units: A New Approach to Lowering Driving Electric Fields

Dielectric elastomers (DEs) have emerged as promising artificial muscles, capable of replicating or even surpassing natural muscle performance. However, their widespread application is severely hindered by the requirement for high driving electric fields. To address this issue, recent research has focused on incorporating ionic units into DEs to enhance polarization. Notably, the effect of ionic units in boosting the dielectric constant far exceeds that of conventional polar groups or high-permittivity fillers, thus enabling successful operation of dielectric elastomer actuators (DEAs) at significantly lower electric fields. This review provides a comprehensive overview of ion modification strategies for DEs. We systematically compare the material design principles between ion-modified DEs and conventional ionic polymers (e.g., those in ionic polymer-metal composites), and elucidate how different ionic components influence the dielectric, mechanical, and actuation properties of DEs. Finally, we highlight the state-of-the-art applications of ion-modified DEs in soft robots and wearable electronics, and discuss the challenges and potential solutions for advancing these materials toward practical low-field actuation.