Electromechanical model of a resonating nano-cantilever-based sensor for high-resolution and high-sensitivity mass detection

A simple linear electromechanical model for an electrostatically driven res onating cantilever is derived. The model has been developed in order to det ermine dynamic quantities such as the capacitive current flowing through th e cantilever-driver system at the resonance frequency, and it allows us to calculate static magnitudes such as position and voltage of collapse or the voltage versus deflection characteristic. The model is used to demonstrate the theoretical sensitivity on the attogram scale of a mass sensor based o n a nanometre-scale cantilever, and to analyse the effect of an extra feedb ack loop in the control circuit to increase the Q factor.