Modeling of Microdevices for SAW-Based Acoustophoresis — A Study of Boundary Conditions

We present a finite-element method modeling of acoustophoretic devices consisting of a single, long, straight, water-filled microchannel surrounded by an elastic wall of either borosilicate glass (pyrex) or the elastomer polydimethylsiloxane (PDMS) and placed on top of a piezoelectric transducer that...

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Bibliographic Details
Main Authors: Nils Refstrup Skov, Henrik Bruus
Format: Article
Language:English
Published: MDPI AG 2016-10-01
Series:Micromachines
Subjects:
Online Access:http://www.mdpi.com/2072-666X/7/10/182
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Summary:We present a finite-element method modeling of acoustophoretic devices consisting of a single, long, straight, water-filled microchannel surrounded by an elastic wall of either borosilicate glass (pyrex) or the elastomer polydimethylsiloxane (PDMS) and placed on top of a piezoelectric transducer that actuates the device by surface acoustic waves (SAW). We compare the resulting acoustic fields in these full solid-fluid models with those obtained in reduced fluid models comprising of only a water domain with simplified, approximate boundary conditions representing the surrounding solids. The reduced models are found to only approximate the acoustically hard pyrex systems to a limited degree for large wall thicknesses and but not very well for acoustically soft PDMS systems shorter than the PDMS damping length of 3 mm.
ISSN:2072-666X