Acoustic gravimetric biosensors, while simple, robust, and low-cost, suffer from low quality factors (Q-factors) due to dissipation in liquid environments. This research introduces a microfluidic QCM (µ-QCM) that mitigates this by confining liquid in microchannels. Finite element analysis and dimensional studies revealed that the ratio of channel width to pressure wavelength (W/λp) and channel height to shear evanescent wavelength (H/λs) are key performance determinants. A fabricated µ-QCM demonstrated a 10-fold improvement in dissipation compared to conventional QCM, offering advantages in data interpretation, sample volume, and temperature control. This paradigm shift enhances sensitivity and accuracy for gravimetric sensing.

Yicheng Zhao, Zehra Parlak, Wenjun Yu, Daniel French, Wilkins Aquino, Stefan Zauscher