Relative Vibration of Suspended Particles With Respect to Microchannel Resonators and Its Effect on the Mass Measurement

In this work, the three-dimensional fluid–solid interaction vibration of particle in the oscillating resonator and its effect on the dynamic characteristics are analyzed and discussed. It demonstrates that the displacement of a particle is composed of two components, one is in phase with the acceleration of resonator and the other is out of phase. The former is responsible for the added mass effect and the latter results in a small damping. A modified measurement principle for detecting the buoyant mass is then presented by considering the in-phase component. The three-dimensional (3D) fluid–solid interaction problem involving the particle, fluid, and resonator is numerically solved, and the effects of density ratio, inverse Stokes number, and the ratio of channel height to particle diameter are studied. Based on the numerical results, a function characterizing the in-phase component is identified through a fitting procedure. According to the modified measurement principle and the analytical expression for the in-phase component, a calibration method is developed for measuring buoyant mass. Using this calibration method, the systematic measurement error induced by the vibration of particles can be effectively reduced.