Parylene-N as a high Temperature thin Film Piezoelectric Material

Thin film piezoelectric materials are in high demand in microsystem devices, but common materials used are stiff ceramic materials. Flexible piezoelectrics are needed for low frequency applications or devices requiring large deformations, but they are often limited in microfabrication due to their low Curie temperatures. This paper investigates the development of a parylene-based high temperature piezoelectric material, and how crystallinity of the film affects the piezoelectric properties. Increasing the films crystallinity for Parylene-N resulted in an increase in d
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value of 12.6 pC/N when the film was annealed at 350°C and the sample maintained its piezoelectric properties when elevated to >250°C. The results demonstrate that modified Parylene-N thin films can be used a MEMS compatible piezoelectric material at elevated temperatures.