Configuration analysis of sensing element for micro-cantilever sensor using dual nano-ring resonator

Abstract

Two photonic crystal rings of hexagonal lattice are lying transversely and longitudinally in silicon micro-cantilever at the junction of the microcantilever and the substrate. This unique dual nano-ring (DNR) resonator demonstrates channel drop filter characteristics. When DNR is used as sensing element of a microcantilever sensor, the wavelength shift of resonant peak measured at the backward drop terminal is a function of applied force at the microcantilever tip. The derived Q-factor is about 3000, and the minimum detectable force can be as small as 37nN for longitudinal case and 16.7nN for transverse case.