Enhanced dielectric, energy storage, and actuated performance of TPU/BaTiO3 dielectric elastomer composites by thermal treatment

In this paper, barium titanate nanoparticles (BaTiO3, BT) were incorporated into the polyurethane (TPU) matrix to prepare dielectric elastomer composites. Then, the composites were thermal treated to improve the interfacial compatibility between TPU and BT, enhance the interface polarization, and improve the dielectric properties. The results showed that the dielectric constant of the composites after thermal treatment at 150? reached to 7.3 at 1 kHz, the elongation at break remained 1934%, and the elastic modulus (Y) dropped to 4.4 MPa. In addition, the discharge energy density reached 73 mJ/cm(3) under an electric field of 300 kV/cm, and charge-discharge energy conversion efficiency was up to 84%. More importantly, the electrically actuated displacement of 2.61 mm at electric field of 160 kV/cm was 1.7 times greater than that of untreated composites. The composites worked stably under the action of the circulating electric field. This study provided a new strategy for obtaining high-performance dielectric elastomer actuators, which were expected to be applied to biomimetic robots, human skin, or dielectric energy storage devices.