A self healable dielectric elastomer artificial muscle

Dielectric elastomers are soft electroactive polymers capable of large-strain actuation with the moniker artificial muscle. However, current dielectric elastomers exhibit limited operational stability when operated at strain and energy density in the neighborhood of natural muscles, due to mechanical fatigue or electrical breakdown. In this work, we design a dielectric elastomer comprising a bimodal network structure and zwitterionic side groups to overcome electro-mechanical instability and enable self-healing. The resulting material demonstrates a stably operable strain of 125% at a field of 25 MV m−1 over 150,000 cycles and can heal from mechanical or electrical damage for longer lifespan. It allows the demonstration of bionic arms and grippers outperforming human arms and hands and capable of recovery from mechanical damage and electrical breakdown. Dielectric elastomers are responsive polymer promising for artificial muscles, though stability is a challenge. Here the authors design a bimodal zwitterionic elastomer to overcome electro-mechanical instability and imparts self-healing properties.