Dimensional effect of SrTiO3 particles on functional performance optimization of polydimethylsiloxane-based composites for dielectric elastomer actuators

Dielectric elastomer materials have a great application potential in electromechanical sensing and energy-harvesting fields. However, the realization of high electro-actuation properties under a relatively low electric field is still a critical challenge. Herein two series of polydimethylsiloxane (PDMS)-based dielectric elastomer composites incorporated SrTiO3 (STO) with distinguishing diameters were prepared through solution-blending and compression moulding methods. The resultant STO/PDMS composites showed significantly enhanced dielectric permittivity and Young’s modulus. Moreover, the PDMS-based composite filled with 4 vol.% nano-scaled STO exhibited an improved electro-actuation strain of 3.3% at a very low electric field of 24 V μm−1, which was 30% larger than that of the neat PDMS. The experimental results revealed that the electro-active performance of dielectric elastomer composite under low electric fields can be influenced by the size of incorporating functional units, and be also successfully optimized by regulating the fillers-matrix interfacial interaction. This study provides a promising strategy to design and fabricate novel dielectric elastomers with advanced low-field driving electro-active properties.