Effective Sensor Properties of a Novel Co-Resonant Cantilever Sensor

Abstract

Co-resonantly coupled cantilever sensors have recently been introduced as a very promising concept to strongly increase the sensitivity of dynamic-mode cantilever MEMS sensors (several orders of magnitude experimentally demonstrated) while maintaining the ease of detection. Mechanical coupling and eigenfrequency matching of a micro- and a nanocantilever lead to a coupled system where any interaction at the highly sensitive nanocantilever alters the oscillatory state of the entire system which is detected at the microcantilever with standard laser-based methods. The coupled system’s sensor properties are described by effective parameters which depend on the subsystems’ properties and the degree of eigenfrequency matching. Here, the focus is on the implications of the effective properties on sensor performance with regard to sensitivity and detectability, which will be illustrated by an exemplary sensor model.