Development of a Torsional Paddle Microresonator for mass detection

This paper presents the development of a torsional micro paddle resonator (TPM), designed for mass detection purposes. The system is designed to operate using a lorentz force electromagnetic driving system, which allows the implementation of a contactless actuating mechanism. Finite element simulations were conducted in order to evaluate the effects of positioning suitable magnets and to optimise the magnetic flux across the TPM. The TPM was fabricated from a 200 nm thick silicon nitride substrate using a focused ion beam (FIB) machine. The fabricated device was characterised in an air medium using a laser vibrometer. The device exhibited a Q factor of 1970 in air, which was determined by application of a Lorentzian curve fit to experimental data and a working frequency of about 1 MHz. This is greater than previously reported Q factor values for integrated micro cantilever sensors.