Smart polydimethylsiloxane sponges with high piezoelectric responses

Abstract In recent years, soft and stretchable electrets have drawn considerable attention for their wide applications in energy harvesters, sensors, and actuators. However, existing electrets struggle to attain both longevity and stretchability (softness), which means charge retention capability and stretchability (softness) of electrets conflict. In this article, one novel soft and stretchable electret (PPSE) with great electromechanical performance is demonstrated. The PPSE is composed of a polydimethylsiloxane (PDMS) sponge and polytetrafluoroethylene (PTFE) particles. The uniformly distributed pores obtained by the sugar leaching method inside the PPSE can not only accumulate macroscopic dipoles but also provide great stretchability, flexibility, and softness for the material. The resulting PPSE has a large value up to 477 pC/N and great charge stability. Moreover, by the virtue of stretchability and softness, it can output electric signals from twisting, bending, and other mechanical interactions without breaking apart. With these great performances, PPSE will potentially enable applications for actuation, sensing, and energy harvesting.