Modeling and simulation of variable thickness based stepped MEMS cantilever designs for biosensing and pull-in voltage optimization

Abstract

Highly sensitive microcantilevers have most commonly and widely been adopted for Bio-MEMS and RF-MEMS applications. The μl and pl blood serums contain few triglyceride (TG) and glucose molecules. Hence, the conventional rectangular microcantilever sensors are not good enough to detect these small TG and glucose concentrations. In mM or μM level TG and glucose detection, the proposed variable sectional thickness based stepped beams showed nearly 3 to 5x more tip deflection then the conventional beam, while surface area, length and width of each beams were kept constant. In RF switching application by electrostatic actuation, the proposed stepped beam switches require less bias voltage for perfect switching and inferred less pull-in voltage requirement as the conventional switch. The mathematical models of proposed variable sectional thickness microcantilevers have also developed, which showed good agreement with simulation results.