title: Optically driven micropump with a twin spiral microrotor.
abstract: An optically driven micropump that employs viscous drag exerted on a spinning microrotor with left- and right-handed spiral blades on its rotational axis has been developed using two-photon microfabrication. It was demonstrated that the twin spiral microrotor provides a higher rotation speed than a single spiral microrotor. The rotation speed reached 560 rpm at a laser power of 500 mW. The twin spiral microrotor was also applied to a viscous micropump with a U-shaped microchannel. To pump fluid, the twin spiral microrotor located at the corner of the U-shaped microchannel was rotated by focusing a laser beam. The flow field inside the U-shaped microchannel was analyzed using the finite element method (FEM) based on the Navier-Stokes equation to optimize the shape of the microchannel. It was confirmed that the rotation of the twin spiral microrotor generated a unidirectional laminar flow. Finally, a tandem micropump using two twin spiral microrotors was driven by a dual optical trapping system using a spatial light modulation technique.
authors.affiliation: Department of Mechanical Engineering, Graduate School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501,Japan. maruo@ynu.ac.jp
authors.forename: Shoji
authors.initials: S
authors.lastname: Maruo
authors.forename: Akira
authors.initials: A
authors.lastname: Takaura
authors.forename: Yohei
authors.initials: Y
authors.lastname: Saito