Design and fabrication of piezoelectric microactuators based on β-poly(vinylidene fluoride) films for microfluidic applications

This paper reports a fabrication method for producing piezoelectric poly(vinylidene fluoride) films in their electroactive beta-phase that features controlled thickness, smooth and flat surface, and high transparency. These piezoelectric films are suitable for being used as integrated microactuators, such as piezoelectric pumps and/or mixers, in microfluidic applications. Their actuation circuit design is also reported. ATR-FTIR, UV-VIS transmittance spectroscopy and SEM techniques were used for calculating the beta-phase content, for determining the transparency and for evaluating the morphology of the produced beta-PVDF films, respectively. beta-PVDF films with a thickness of about 25 mu m were deposited by spin-coating. It was concluded that the processing parameter that mostly affect the films quality was their drying temperature. Indeed, the drying temperature of 30 degrees C proved to be the most suitable for obtaining non-porous and transparent films, with a beta-phase content of approximately 75%.