Conditioning Circuit for Simultaneous Sensing and Actuation in Piezoelectric MEMS Resonators

This paper presents a conditioning circuit able to simultaneously actuate and measure the output of an integrated resonator with embedded aluminum nitride (AlN) layer. The basic idea is to use this active layer as actuation transducer and as sensor to detect the resonant frequency of a MEMS oscillator. In this context a suitable conditioning system has been developed and the working principle has been demonstrated with a MEMS cantilever fabricated in PiezoMUMPs technology, used as a mass sensor. The sensor was characterized by means of known masses of Al2O3 nano-particles, deposited at the free end of the beam. The proposed architecture has been studied and modeled, and a prototype of the MEMS has been characterized demonstrating the validity of the proposed technique.