Laser manipulation in liquid crystals: an approach to microfluidics and micromachines
Laser trapping of particles in three dimensions can occur as a result of the refraction of strongly focused light through micrometre-sized particles. The use of this effect to produce laser tweezers is extremely common in fields such as biology, but it is only relatively recently that the technique...
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Published in | Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences Vol. 364; no. 1847; pp. 2789 - 2805 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
London
The Royal Society
15.10.2006
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Subjects | |
Online Access | Get full text |
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Summary: | Laser trapping of particles in three dimensions can occur as a result of the refraction of strongly focused light through micrometre-sized particles. The use of this effect to produce laser tweezers is extremely common in fields such as biology, but it is only relatively recently that the technique has been applied to liquid crystals (LCs). The possibilities are exciting: droplets of LCs can be trapped, moved and rotated in an isotropic fluid medium, or both particles and defects can be trapped and manipulated within a liquid crystalline medium. This paper considers both the possibilities. The mechanism of transfer of optical angular momentum from circularly polarized light to small droplets of nematic LCs is described. Further, it is shown that droplets of chiral LCs can be made to rotate when illuminated with linearly polarized light and possible mechanisms are discussed. The trapping and manipulation of micrometre-sized particles in an aligned LC medium is used to provide a measure of local shear viscosity coefficients and a unique test of theory at low Ericksen number in LCs. |
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Bibliography: | istex:D7984EE5EE6CE34EED83C42F057B2AE2BAAA34A0 ArticleID:rsta20061855 href:2789.pdf ark:/67375/V84-BK1D74BX-J Discussion Meeting Issue 'New directions in liquid crystals' ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1364-503X 1471-2962 |
DOI: | 10.1098/rsta.2006.1855 |