Converting Parylene C into a Thin Film Piezoelectric Material

Flexible polymer based piezoelectric materials are being extensively investigated, but their role in microelectromechanical systems (MEMS) is still limited due primarily to their low temperature capabilities. This paper focuses on converting a widely used MEMS polymer (Parylene-C) into a piezoelectric film. The paper investigates how crystallinity of the film effects the piezoelectric properties along with varying the poling method and properties. The results demonstrate that through electric poling Parylene-C can generate piezoelectric properties and that annealing the samples significantly enhances the piezoelectric properties. We were able to achieve relatively high d33 values of 5.4 pC/N when annealed at 150°C. We demonstrated that both poling methods and the properties of the poling such as temperature and applied voltage influence the properties and needs to be further investigated.