Surface Acoustic Wave Microfluidics

Surface acoustic waves (SAWs) are nanometre order electroelastic analogues of earthquake waves that propagate along the surface of a piezoelectric substrate. Due to the fluid-structural coupling between the undulations along the substrate surface and the fluid above the substrate, substantial acoustic energy is transferred into the fluid, which can then be exploited to drive a wide range of microfluidic phenomena, from vibration, which has interesting implications for colloidal patterning and particle trapping/manipulation, thin film and drop translation, jetting and even nebulisation. Additionally, the SAW can be harnessed to drive azimuthal rotation in a fluid, thus constituting a powerful mechanism for driving chip-scale microcentrifugation.

Relevant Publications

1. LY Yeo, JR Friend. Ultrafast Microfluidics Using Surface Acoustic Waves. Invited paper: Biomicrofluidics 3, 012002 (2009).
2. RP Hodgson, M Tan, L Yeo, J Friend. Transmitting High Power RF Acoustic Radiation via Fluid Couplants into Superstrates for Microfluidics. Appl Phys Lett 94, 024102 (2009).
3. J Friend, LY Yeo. Microscale Acoustofluidics: Microfluidics Driven via Acoustics and Ultrasonics. Rev Mod Phys 83, 647–704 (2011).
4. LY Yeo, JR Friend. Surface Acoustic Wave Microfluidics. Annu Rev Fluid Mech 46, 379–406 (2014).

Press Releases

1. Sound-Blasting Chips for On-the-Spot Forensics, New Scientist, 24 May 2010.