Effects of the soft matrices in dielectric elastomer actuator electrodes on their actuation performance

Dielectric elastomer actuator (DEA) based flexible and stretchable electronics have attracted considerable attention over the past decades. The electrode components play an important role in the DEA performance. In this work, we studied how the incorporation of soft matrices in the electrodes affects the DEA actuation. The ultrasonic spraying was used to fabricate multiwall carbon nanotube (MWCNT) based electrodes for DEA. The results indicated that the addition of a water-soluble block polymer and silicone gel (acting as the soft matrices) could improve the actuation of the DEA with neat MWCNT electrodes by ~10% and ~24%, respectively. An inkjet printing ink, consisting of polydimethylsiloxane (PDMS), carbon black (CB) and chlorobenzene, was further developed. The stability, particle size, resistance, and morphology of 1-3 printing layers were characterized. The DEA with the inkjet-printed CB/PDMS electrodes showed 50% area stain at 2500 V, which is higher than the actuation with neat CB powder or CNT electrodes reported previously. Both results of the ultrasonic spraying and inkjet printing confirmed that the incorporation of soft matrices in the electrodes is helpful for DEA actuation.