Acoustophoresis of Disks

Unlike acoustophoresis of spherical particles, acoustophoresis of disk-shaped particles also shows an acousticradiation torque which induces disk rotations. The present paper aims to study the acoustophoretic dynamics of disks which are exposed to an ultrasonic standing wave in a microfluidic context. A numerical model allowed to calculate torques beyond the existing simplified analytical models from literature. Numerical as well as experimental results were found to agree for microfluidic disk-shaped alumina particles of 7.5 μm diameter at ultrasonic frequencies around 2 MHz.Application potential is expected for acoustophoresis of disk-shaped cells in biomedical devices (e.g. red blood cells in flow cytometers), assembly of disks or micromaterial development.