A Piezoelectric Thermoplastic Elastomer Containing A Bent Core Liquid Crystal

A special pressure molding technique, in which a polar smectic bent-core liquid crystal material was confined in a thermoplastic elastomer film, created soft, biocompatible and highly piezoelectric materials. The converse piezoelectric response of the polymer films was evaluated by interferometry experiments and the piezoelectric coupling constants were found to be d₃₃ ~ 1 nm/V. This piezoelectric effect is larger than of the commercially available piezoelectric ceramics, and is comparable with cellular electrets and electrospun fiber mats containing ferroelectric nanoparticles. Small Angle X-ray Scattering (SAXS) results show that the confined liquid crystal becomes aligned in the polymer during the pressure release. The large piezoelectric effect is due to the vitrified macroscopic polarization created during this process.  These materials are promising for practical applications such as in actuator technologies in biomedical devices.