title: Surface acoustic wave induced particle manipulation in a PDMS channel--principle concepts for continuous flow applications.
abstract: A device for acoustic particle manipulation in the 40 MHz range for continuous-flow operation in a 50 μm wide PDMS channel has been evaluated. Unidirectional interdigital transducers on a Y-cut Z-propagation lithium nixobate wafer were used to excite a surface acoustic wave that generated an acoustic standing wave inside the microfluidic channel. It was shown that particle alignment nodes with different inter-node spacing could be obtained, depending on device design and driving frequency. The observed inter-node spacing differed from the standard half-wavelength inter-node spacing generally employed in bulk acoustic transducer excited resonant systems. This effect and the related issue of acoustic node positions relative the channel walls, which is fundamental for most continuous flow particle manipulation operations in channels, was evaluated in measurements and simulations. Specific applications of particle separation and alignment where these systems can offer benefits relative state-of the art designs were identified.
authors.affiliation: Department of Engineering Sciences, Ångström Laboratory, Uppsala University, PO Box 534, SE-75121 Uppsala, Sweden. johansson.lek@gmail.com
authors.forename: Linda
authors.initials: L
authors.lastname: Johansson
authors.forename: Johannes
authors.initials: J
authors.lastname: Enlund
authors.forename: Stefan
authors.initials: S
authors.lastname: Johansson
authors.forename: Ilia
authors.initials: I
authors.lastname: Katardjiev
authors.forename: Ventsislav
authors.initials: V
authors.lastname: Yantchev
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D002470:Cell Survival; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D044085:Microfluidics; D013016:Sound; D014159:Transducers; D014465:Ultrasonics