Acoustofluidics
Sound waves can be used to push cells and particles around inside a microfluidic channel without touching them, which is useful for separating cells or concentrating nanoparticles for diagnosis. Standing surface acoustic waves create a pattern of forces across the channel, and the result depends on details of the device. In this project, led by X. Yang and Dongfang Liang, finite-element models showed how the height of the channel relative to the acoustic pattern (Li et al., Physics of Fluids 2023) and the acoustic properties of its walls (Li et al., Computer Methods and Programs in Biomedicine 2025) control where particles end up. Adding a temperature gradient to the acoustic field concentrates nanoparticles more efficiently than either alone (Dong et al., Physics of Fluids 2024).