Three-Dimensional Numerical Modeling of Surface-Acoustic-Wave Devices: Acoustophoresis of Micro- and Nanoparticles Including Streaming

Surface-acoustic-wave (SAW) devices are often made in acoustically soft polymers due to ease of fabrication, but at the cost of high acoustic attenuation. To improve the design of SAW devices, the authors present a comprehensive three-dimensional numerical model that includes SAW transducers, a chip containing a water-filled microchannel, and the acoustic streaming and radiation forces acting on particles suspended in the channel fluid. The model is validated by experiment, and explains how the use of glass leads to SAW devices with increased energy efficiency and improved acoustophoretic focusing ability, compared to polymer-based devices.