A Proposal for a Novel Surface-Stress Based BioMEMS Sensor Using an Optical Sensing System for Highly Sensitive Diagnoses of Bio-particles.

In this paper, a BioMEMS sensor by using a surface-stress sensing approach, connected to a highly sensitive optical sensing system, is proposed to diagnose various types of biomolecules. The MEMS transducer is composed of a fixed-fixed beam with immobilized receptors on the surface which is connected to a Ring Resonator (RR) filter. The interaction between the target biomolecules and the receptors induces surface stresses on the beam. This stress results in the beam deformation which leads to changes in the coupling coefficient of the RR. Consequently, the transmission spectrum of the RR experiences changes, measured by using an optical photo-detector. Therefore, by analyzing the response of the photo-detector output, one can detect the number of target biomolecules in the sample and assign a level of contamination, infection or bioparticles, caused by the specific disease. Furthermore, the MEMS functional characteristics and the optical properties of the proposed biosensor are designed and analyzed respectively by using the finite element method (FEM) and the finite difference time domain (FDTD) approach. The obtained functional characteristics of the proposed device show that the present optical BioMEMS sensor can be used for highly sensitive diagnoses of various types of diseases and their progress level.