Smart material for printing: piezo-electric polymer film

Abstract

Poly(vinylidene fluoride) (PVDF) has four crystalline structures (α, β, γ and δ phase structures) in solid state. The extraordinary PVDF electrical properties are directly attributable to its crystalline structure. Only α-phase structure shows no crystal dipole, but this phase structure is converted easily into other phase structures according to some schemes. Generally, PVDF is given uniaxial stretch and polarization processes in order to convert into β-phase or γ- phase structure before sensor and actuator film use. However, we recently found a novel method in which PVDF film structure became β-phase or γ-phase without mechanical deformation processes. Furthermore, this technique enables us to apply printing technology, and realize the creation of free-form 3D sensor and actuators. In the development of printed PVDF film, the integration of material fabrication technique, its crystalline structure state, forming technology and macroscopic electrical properties will be important research topics. Up to the present, authors have constructed PVDF film fabrication techniques. As a result, PVDF crystalline structure was changeable using the techniques. In addition, some in-house PVDF property measurement systems have been constructed for the sensor and actuator applications. Furthermore, a novel PVDF printer, which can draw freeform 2D PVDF film, has been developed on the basis of PVDF film fabrication results. In present paper, we would introduce our PVDF film fabrication techniques, in-house PVDF property measurement systems and P-p printer.