Synergistic Design of Resonant Elements and Force Multipliers to Boost the Sensitivity in Resonant Sensing Applications

Abstract

This letter introduces a versatile design methodology to enhance the sensitivity of resonant sensors through geometrical modifications to their resonant elements and force-multiplier mechanisms. These improvements are achieved, first, by modifying the boundary conditions of the common resonant beam sensing elements to increase their responsiveness to axial forces and, second, by enhancing the efficiency of force-multiplier mechanisms to go beyond basic force-multiplication of the presently used lever structures. The effectiveness of these modifications is validated through simulations and experimental testing of fabricated test structures. We also demonstrate the utility of the approach through the analysis, design, and fabrication of several resonant accelerometers as prime candidates that benefit from these advancements. Experimental results demonstrate a 35% increase in device sensitivity compared to a baseline resonant accelerometer while offering a higher quality factor for the resonant beam elements, which can help improve the resolution of the sensor. The proposed approach does not require changes to microfabrication processes and can be utilized to improve the performance of various devices through simple structural modifications.