Design and Modeling of a Novel Two Dimensional Nano-Scaled Force Sensor Based on Silicon Photonic Crystal

Photonic crystal, which is an attractive optical structure for controlling and manipulating the flow of light, has been widely used to design mechanical sensors in microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS). In this work, a novel two dimension nano-scaled force sensor based on silicon photonic crystal, in which a nanocavity is embedded in an L-shaped microcantilever, is developed and studied numerically. This microcantilever is extremely sensitive to the small refractive index changes produced by two dimensional component forces. The relationship between the force and the output wavelength is determined using finite element method and finite difference time-domain method. As we found, the range of the force sensor in each component force in X and Y directions are 0-1μN.And the resolutions of each component force in X and Y directions are 1.891 nm/μN and 1.418 nm/μN, respectively, for a 30μm long and 15μm wide cantilever. The novel photonic crystal sensor shows promising linear characteristics as an optical nanomechanical sensor.