High-throughput cell manipulation using low-frequency quasi-Scholte wave-based acoustofluidics

High-throughput and biocompatible acoustofluidic manipulation of living cells and microparticles is essential for applications in cellular medicine, tissue engineering, and drug screening. Conventional surface acoustic wave (SAW)–based devices have been widely adopted; however, their high operating frequencies limit throughput, and the conversion of SAWs into leaky bulk waves in liquids induces strong acoustic streaming that compromises manipulation stability. Here, we present a low-frequency acoustofluidic device that exploits non-leaky quasi-Scholte waves in a piezoelectric thin plate to achieve high-throughput, stable, two-dimensional manipulation of particles and cells. Numerical simulations and laser Doppler vibrometry measurements confirm robust excitation of the quasi-Scholte mode, revealing evanescent acoustic fields with strong vertical gradients and well-defined in-plane standing waves in liquid. Experiments with microparticles and in vitro cells further demonstrate stable one- and two-dimensional patterning over large areas while maintaining high cell viability. This quasi-Scholte-wave-based acoustofluidic platform provides a reliable, effective, and high-throughput approach for precise manipulation of cells and biomaterials.