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Issue 14, 2010
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Capillary motor driven by electrowetting

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A micro-structure supported on a droplet is subjected to capillary force and aligned dependent on its shape. If the droplet's boundary conditions at the bottom and the micro-structure are non-circular, capillary torque is exerted on the structures. The direction of torque is determined by the boundary conditions and the position of the structure. By changing the boundary conditions continuously, rotational motion of a plate was achieved. The boundary conditions of the droplet were controlled by electrowetting. We patterned electrodes in an annular shape on the plate supporting the droplet. By changing the voltage-applied electrodes, the boundary conditions were changed and the plate is rotated. The droplet and the plate worked as a capillary motor with this method. We report the relationship between the characteristics of the capillary motor and its rotational motion. We sandwiched a 3.0-μL water droplet between two plates and achieved a rotational motion of 720 rpm at maximum.

Graphical abstract: Capillary motor driven by electrowetting

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Publication details

The article was received on 21 Jan 2010, accepted on 17 Mar 2010 and first published on 26 Apr 2010

Article type: Paper
DOI: 10.1039/C001211D
Citation: Lab Chip, 2010,10, 1781-1786

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    Capillary motor driven by electrowetting

    A. Takei, K. Matsumoto and I. Shomoyama, Lab Chip, 2010, 10, 1781
    DOI: 10.1039/C001211D

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