High quality factors of silicon membranes with piezoelectric actuation and detection scheme for biosensing purpose in liquid media

Abstract

The paper is about 4 times 4 matrices of piezoelectric membranes that were fabricated by standard micromachining techniques starting with silicon-on-insulator (SOI) wafer. Each membrane (circular shaped) can be individually addressed for actuation and sensing applications through a PbZr(x)Ti(1-x)O3 (PZT) 800-nm thick film. The main objective of this work is to study the dynamic behavior of the piezoelectric membranes in air and liquid media. The results showed high quality factors in air (up to 150) and in water-glycerol (lowered by a factor 4 for a glycerol proportion in water less than 30%) while the resonant frequencies were significantly decreased by the liquid apparent added mass effects