Electromechanical transduction and actuation performance of P(VDF-TrFE)/P(VDF-TrFE-CTFE) electroactive polymer blends

Abstract

Electroactive polymer (EAP) blends of relaxor-ferroelectric P(VDF-TrFE-CTFE) and ferroelectric P(VDF-TrFE) were investigated for enhanced electromechanical transduction. Blends containing 0–30 wt% copolymer were stencil-printed onto thin steel substrates for characterization in dielectric, mechanical, and structural properties, while unimorph cantilever actuators were produced for characterizing transduction. Copolymer addition increased the Young's modulus and promoted ferroelectric ordering while reducing dielectric permittivity and dielectric loss in the EAPs. Maximum quasi-static actuation displacements improved from 8.1 mm at 50 V/µm in neat terpolymer samples to 9.2 mm at 48.3 V/µm in 10 wt% blends, that showed the highest overall improvements. At 20 V/µm, the maximum deflection and transducer efficiency respectively reached 2.1 mm and 0.0576%, corresponding to 94.4% and 357% improvements over the pure terpolymer. Under dynamic operation, the 10 wt% blends also produced the highest resonant displacement (2.30 mm at 6.7 V/µm), yielding a 53.7% improvement over the pure terpolymer. Higher copolymer contents (20 and 30 wt%) further increased in stiffness and unimorph efficiency but showed lower displacement due to reduced EAP film stress. These results demonstrate that polymer blending is an effective strategy to tune transduction performance in PVDF-based unimorph actuators, with further gains expected through optimization of blend composition and actuator design.