Design and simulation of a resonance-based MEMS viscosity sensor

Abstract

The paper presents the design and simulation of a MEMS-based resonant viscosity sensor using a piezoelectric micro diaphragm. The sensor comprises a vibrating diaphragm as a resonating element with piezoelectric excitation and detection. As the viscosity of the liquid beneath the diaphragm changes, the resonant frequency also changes. A numerical model of a diaphragm is designed in the COMSOL Multiphysics FEM tool, and its resonance characteristics were studied with a fluid of different viscosities beneath it. To support the numerical simulation results, mesoscale experimentation was also performed using a stainless steel thin sheet as a diaphragm and also to verify the proof of concept of the proposed sensor. The major benefit of the proposed sensor is that it uses the resonance measurement principle and can be shown to offer good stable performance, resolution, reliability, and response time. The proposed sensor can also be showcased as a hand-held laboratory product for quick viscosity measurements