Increased electroaction through a molecular flexibility tuning process in TiO2–polydimethylsilicone nanocomposites

Flexible polymer materials with obvious electrostriction characteristics display a significant potential for application as novel potential actuators in the future. We report advanced TiO2–polydimethylsilicone (TiO2–PDMS) nanocomposites with electroaction that is effectively increased through a molecular flexibility tuning process. The increase in the electromechanical sensitivity (by 550%) and actuation strain (by 230%) under a low electric field in low elastic modulus TiO2–PDMS composites originates from the flexibility tuning process by the introduction of dimethylsilicone oil (DMSO). The DMSO is miscible with PDMS resulting in a uniform composition at the molecular level, which can significantly decrease the elastic modulus of the dielectric elastomer composites from 820 kPa to 95 kPa. The experimental results are interpreted using the swelling elastomers theory. It suggests that reducing the elastic modulus could be a good strategy to improve the actuation performance with a low electric field.