Novel mass detection based on magnetic excitation in anti-resonance region

Abstract

A novel mass sensor resonator in anti-resonance mode to detect the particles in the order of picogram is proposed. The model is a cantilever beam composed of a PZT-5A layer as readout and Metglas 2605SC as a magnetostrictive material. The cantilever beam is exposed to harmonic magnetic field; once the Metglas experiences the magnetic field, undergoes mechanical strain and as a result the PZT-5A gives off electrical potential difference throughout the output circuit. The governing motion equations in the presence of the added distributed mass is derived and numerically integrated over the time. The voltage frequency response curves are determined. The results reveal that for small enough external loads in the output circuit between two successive natural frequencies, there exist an anti resonance region where the steady state response amplitude dramatically drops. Once the added mass is deposited on the micro beam the frequency response curve is shifted along the frequency domain and as a result the response amplitude suddenly jumps which is used as a measure of the added mass.