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Issue 12, 2006
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Optical force field mapping in microdevices

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We present a method for characterizing microscopic optical force fields. Two dimensional vector force maps are generated by measuring the optical force applied to a probe particle for a grid of particle positions. The method is used to map out the force field created by the beam from a lensed fiber inside a liquid filled microdevice. We find transverse gradient forces and axial scattering forces on the order of 2 pN per 10 mW laser power which are constant over a considerable axial range (>35 µm). These findings suggest future useful applications of lensed fibers for particle guiding/sorting. The propulsion of a small particle at a constant velocity of 200 µm s−1 is shown.

Graphical abstract: Optical force field mapping in microdevices

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Publication details

The article was received on 19 Jun 2006, accepted on 07 Sep 2006 and first published on 22 Sep 2006

Article type: Technical Note
DOI: 10.1039/B608669A
Lab Chip, 2006,6, 1545-1547

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    Optical force field mapping in microdevices

    G. Knöner, A. Ratnapala, T. A. Nieminen, C. J. Vale, N. R. Heckenberg and H. Rubinsztein-Dunlop, Lab Chip, 2006, 6, 1545
    DOI: 10.1039/B608669A

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