Towards materials with enhanced electro-mechanical response: CaCu3Ti4O12/Polydimethylsiloxane composites

We describe a straightforward production pathway of polymer matrix composites with increased dielectric constant for dielectric elastomer actuators (DEAs). Up to date, the approach of using composites made of high dielectric constant ceramics and insulating polymers has not evidenced any improvement in the performance of DEA devices, mainly as a consequence of the ferroelectric nature of the employed ceramics. We propose here an unexplored alternative to these traditional fillers, introducing Calcium Copper Titanate (CCTO) CaCu3Ti4O12, which has a giant dielectric constant making it very suitable for capacitive applications. All CCTO/Polydimethylsiloxane (PDMS) composites developed display an improved electro-mechanical performance. The largest actuation improvement was achieved for the composite with 5.1 vol.% of CCTO, having an increment in the actuation strain of about 100% together with a reduction of 25% in the electric field compared to the raw PDMS matrix.
LJR, MH, MALM and RV gratefully acknowledge the financial support of the Spanish Ministry of Science and Innovation (MICINN) through project MAT 2010-18749 and the 7th Framework Program of E.U. through HARCANA 55 (NMP3-LA-2008-213277). RV acknowledges the mobility grant PA1003132 from CSIC. PL, MAR and JFF kindly acknowledge financial support from the MICINN project MAT 2010-21088-C03-01.The authors are in debt to Manuel Rus, from ICTP-CSIC, for the technical support in the electro-mechanical experimental set-up.