Acoustic Centrifugation Facilitating Particle Sensing in Liquid on a Piezoelectric Resonator

Abstract

We have developed a hybrid device that fuses the techniques of acoustofluidic localization and resonator-based mass sensing of particles in liquid-phase for in-situ analysis in a <inline-formula> <tex-math notation="LaTeX">$\mu \text{L}$ </tex-math></inline-formula> droplet. An elliptic plate resonator (EPR) was used in this work to verify the capability of acoustofluidic manipulation on a resonator chip. Particles were focused on the EPR by the acoustic tweezers to increase the effectiveness of detection. The EPR has a reasonably high liquid-phase quality factor (<inline-formula> <tex-math notation="LaTeX">${Q}$ </tex-math></inline-formula>) and low motional resistance (<inline-formula> <tex-math notation="LaTeX">${R}_{m}$ </tex-math></inline-formula>) to allow the detection of focused particles in liquid. Moreover, the resonator chip can be detached from the acoustic tweezing device without damage. This allows replacement of just the chip when required. A potential application of this work is organizing and sensing cells on-chip using the concepts herein.