title: Acoustomicrofluidic application of quasi-shear surface waves.
abstract: The paper analyzes the possibility of using predominantly boundary polarized surface acoustic waves for actuating fluidic effects in microchannels fabricated inside containers made of PDMS. The aim is to remove a shortcoming peculiar to conventionally utilized predominantly vertically polarized waves. Such waves strongly attenuate while they propagate under container side walls because of the leakage into them. Due to a specific feature of PDMS - extremely small shear elastic modulus - losses of boundary polarized modes should be far smaller. The amplitude of vertical mechanical displacements can be increased right inside the channel owing to the scattering of acoustic fields. As an example, the predominantly vertically polarized surface wave on 128YX LiNbO3is compared with the quasi-shear leaky wave on 64YX LiNbO3. Our computations predict that, given the electric power supplied to the launching transducer, the quasi-shear wave will drive the fluid more efficiently than the surface wave on 128YX LiNbO3when the container wall thickness is larger than 25-30 wavelengths, if there are no additional scatterers inside the channel. In the presence of a scatterer, such as a thin gold strip, the quasi-shear wave can be more efficient when the wall thickness exceeds 10-15 wavelengths.
authors.affiliation: Institute of Crystallography FSRC "Crystallography and Photonics", Russian Academy of Sciences, Leninskii pr. 59, Moscow 119333, Russia; National University of Science and Technology "MISIS", Leninsky pr. 4, Moscow 119049, Russia. Electronic address: alexandre_dar@mail.ru.
authors.forename: A N
authors.initials: AN
authors.lastname: Darinskii
authors.affiliation: IFW Dresden, SAWLab Saxony, P.O. 27 00 16, D-01171 Dresden, Germany; InnoXacs, Am Muehlfeld 34, D-01744 Dippoldiswalde, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Weihnacht
authors.affiliation: IFW Dresden, SAWLab Saxony, P.O. 27 00 16, D-01171 Dresden, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Schmidt