Biosensors are an integral part of medical diagnostics. The materials, as well as the structural makeup used in these devices, are being upgraded through various solid-state processes, chemical processes, and micro-machining techniques. The material porous Silicon (PSi) has biosensing capabilities that can cause immobility of the attached biomolecules in its pores. The variation in porosity with current density was presented and related to the different etched stages of the silicon surface. PSi is a novel patterned cantilever MEMS resonator membrane that can be utilized for high-precision biosensing. Finite element modeling shows the strain distribution in the novel design. A theoretical base of the coupled oscillations in the sensors for the difference in dimension separation and absorbance was given.