Towards a Hybrid Mass Sensing System by Combining a QCM Mass Sensor With a 3-DOF Mode Localized Coupled Resonator Stiffness Sensor

Abstract

This paper describes a hybrid mass sensing system comprising a QCM (quartz crystal microbalance) mass sensor operating under atmospheric pressure and a 3-DOF mode localized coupled resonator operating in vacuum. Nanoparticles as consecutive mass perturbations are added onto the QCM, the output signals with respect to the amount of mass change are then being manipulated to generate electrostatic forces. Subsequently, the electrostatic forces act on the 3-DOF mode localized coupled resonator as external stiffness perturbations. The output metrics of the hybrid system were defined as: the resonant frequency shifts, vibration amplitude changes, and the changes in resonance amplitude ratio. Measured data was analyzed for these metrics and compared. This work demonstrated that the proposed hybrid mass sensing system attained a 𝟐. 𝟓 × 𝟏𝟎 𝟔 𝑵(𝐦 • 𝐤𝐠) −𝟏 mass to stiffness transduction factor, and has the potential to be employed as a direct liquid contact biochemical transducer.

Platform for Weakly Coupled Electro-Mechanical Resonators with Arbitrary Tunability

“…In recent years, there has been a growing interest in weakly coupled resonators due to their enhanced sensitivity and common-mode resilience in contrast to single resonators [1][2][3]. However, conventional coupled resonators are limited in their adjustability after fabrication as they are purely mechanical resonators.…”