Investigation of Localized Flexural Lamb Wave for Acoustofluidic Actuation and Particle Control

This paper presents an investigation of the acoustofluidic capabilities of highly localized flexural Lamb waves generated on a planar device via a piezoelectric layer deposited on a silicon layer of the silicon-on-nothing wafer. Silicon migration by high temperature annealing allows for the formation of a $2\ \mu \mathrm{m}$ -thin suspended membrane acting as a waveguide for flexural Lamb waves. Transportation, self-alignment and trapping of micro-scale polystyrene particles are achieved using traveling waves and standing waves inside a water droplet deposited atop of the chip.