摘要
This work presents a robust and modular strategy for enabling high-fidelity (i.e., high signal-to-noise ratio, SNR) operation of MEMS resonators in conductive liquid environments, common in biological and chemical sensing. While bottom-electrode signal routing effectively shields the AC signal path from electrical leakage and interference, it still introduces extra parasitic capacitive feedthrough (FT) that degrades signal clarity. To overcome this, we integrate a PCB-level electromagnetic FT cancellation technique based on electromagnetic interaction between interconnects. Such a cancellation loop, decoupled from the MEMS device and implemented at the PCB level, suppresses FT without affecting the mechanical structure, enabling modular optimization. Experimental results show that combining this method with bottom routing improves stopband rejection in saline medium by a factor of three (from 5 dB to 15 dB) and significantly enhances phase change at resonance. This approach enables reliable detection of resonance in conductive liquids, even under damping effects, providing a practical solution for deploying MEMS resonators in fluidic environments requiring precise, real-time sensing.