Micro-opto-electro-mechanical system based microcantilever sensor for biosensing applications

Abstract

The strain sensing action of a photonic integrated microcantilever induced by the binding of biomolecules such as antibodies and antigens is an important factor in biosensing applications. Since sensitivity is the key factor in sensor performance for early detection of any bio analyte, increasing the sensitivity of the photonic integrated microcantilever becomes more critical. This can be achieved by varying the geometry of the microcantilever. Two photonic integrated microcantilever configurations—stepped profile and T-shaped microcantilevers—are considered for pressure sensing, and a comparative analysis between both designs is presented. The sensitivity of the microcantilever is improved for a small magnitude of force such as 0.1 MPa to 0.4 MPa for the T-shaped profile of the microcantilever. The resonant wavelength and wavelength shift between two structures are evaluated for various ranges of applied pressure. Sensitivities of the stepped profile and T-shaped microcantilevers are calculated as 0.58 nm/MPa in the range of 10 MPa to 25 MPa, and 92 nm/MPa in the range of 0.1 MPa to 0.4 MPa, respectively. Simulation results show that the proposed sensing configuration, i.e., T-shaped microcantilever, has high sensitivity and a significant range of wavelength at low-pressure values. This capability of the T-shaped microcantilever enhances feasibility for future fabrication and implementation in different biomedical applications.