Microparticle acoustophoresis in aluminum-based acoustofluidic devices with PDMS covers

Research output: Contribution to journalArticle

Abstract

We present a numerical model for the recently introduced simple and inexpensive micromachined aluminum devices with a polydimethylsiloxane (PDMS) cover for microparticle acoustophoresis. We validate the model experimentally for a basic design, where a microchannel is milled into the surface of an aluminum substrate, sealed with a PDMS cover, and driven at MHz frequencies by a piezoelectric lead-zirconate-titanate (PZT) transducer. Both experimentally and numerically we find that the soft PDMS cover suppresses the Rayleigh streaming rolls in the bulk. However, due to the low transverse speed of sound in PDMS, such devices are prone to exhibit acoustic streaming vortices in the corners with a relatively large velocity. We predict numerically that in devices, where the microchannel is milled all the way through the aluminum substrate and sealed with a PDMS cover on both the top and bottom, the Rayleigh streaming is suppressed in the bulk thus enabling focusing of sub-micrometer-sized particles.

Details

Authors
Organisations
External organisations
  • Technical University of Denmark
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering

Keywords

  • Acoustofluidics, Aluminum microdevices, Microparticle acoustophoresis, Numerical modeling, Polydimethylsiloxane (PDMS) covers
Original languageEnglish
Article number292
JournalMicromachines
Volume11
Issue number3
Publication statusPublished - 2020
Publication categoryResearch
Peer-reviewedYes