Enhanced Electro-Actuation and Self-Healing Properties of Dielectric Elastomers by Introducing Ultrafine BaTiO3 and Semi-Interpenetrating Macromolecules

The dielectric elastomer (DE) is a kind of electroactive polymer that can deform under an applied electric field. However, it remains challenging to effectively enhance the electro-actuation of the DE at low driving electric fields. Furthermore, during long-term utilization, the DE is vulnerable to aging and mechanical damage, which inevitably affects its electromechanical stability and seriously shortens its service life. Thus, it is crucial to prepare DE composites featuring large low-field-actuated strain along with self-healing capability. Herein, an ultrafine BaTiO3 (uf-BaTiO3) nanoparticle and methyl vinyl silicone (MVQ) incorporating the polydimethylsiloxane (PDMS)-based DE composite was prepared to construct a typical semi-interpenetrating polymer network. The uf-BaTiO3 nanoparticles with a large specific surface area can form more heterogeneous interfaces with the PDMS matrix, leading to a significant improvement in interfacial polarization. Meanwhile, the MVQ macromolecule can avoid the introduction of defects within DE composites due to its excellent interfacial compatibility with the PDMS matrix. In particular, an excellent electro-actuated strain of 50.7% at an electric field of 50 V/μm and a high self-healing efficiency of 76% in a short time of 15 min can be obtained from the 5 MVQ/3 wt % uf-BaTiO3/PDMS composite. This study provides a feasible route for preparing advanced DE composites with the simultaneously improved low-field electro-actuation property and self-healing capability.