Manipulation of Particles in a Microchannel with Various Geometric Spaces Using Ultrasound

• Published in: Japanese Journal of Applied Physics 2011-07, Vol.50 (7), p.07HE27-07HE27-4
• Main Authors: Kozuka, Teruyuki, Yasui, Kyuichi, Hatanaka, Shin-ichi, Tuziuti, Toru, Suzuki, Kazuyuki, Towata, Atsuya
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.50.07HE27

A noncontact micromanipulation technique is required in micromachine technology, biotechnology, and other fields. In this study, a standing wave field was generated in a microchannel with a geometric space. It was possible to trap small objects at nodes of the sound pressure distribution in the medium. A microchannel of $1\times 50\times 1$ mm 3 was formed at the center of a glass plate of $50\times 50\times 5$ mm 3 . In the experiment, when the liquid water containing particles was injected into the microchannel on the glass plate irradiated by ultrasound, the particles flowed along several layers. It was shown that the traveling wave was transmitted into the microchannel and the standing wave field was formed in the microchannel. The micromanipulation technique enabled the control of the direction of the particle flow by changing the ultrasound frequency in branched channels with a geometric region at the junction. Moreover, in a triangular region, the particles moved towards the top from the base of the triangle with a fixed frequency.