Piezoelectric-actuated, piezoresistive-sensed circular micromembranes for label-free biosensing applications

摘要

In this paper, we report on the fabrication and characterization of the dynamic behavior of circular micromembranes integrating a piezoelectric thin film for actuation and a boron-doped silicon piezoresistor for sensing purposes. Resonant frequencies corresponding to high-order modes of vibration are measured, respectively, in air and deionized water. The measurements are compared with theoretical values calculated using the extended Lamb's model [H. Lamb, Proc. R. Soc. London 98, 205 (1920)] adapted to the microscale. Moreover, label-free detection of Bacillus atrophaeus (or B. atrophaeus) with a concentration of 10~8 spores/mL is repeatedly performed in real-time which assesses the biosensing potential of microscale circular membranes bearing actuation and sensing elements.