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Friday, August 10, 2018

Natural convection induced by an optically fabricated and actuated microtool with a thermoplasmonic disk

Einstom Engay, Ada-Ioana Bunea, Manto Chouliara, Andrew Bañas, and Jesper Glückstad

Two-photon polymerization was employed for fabricating microtools amenable to optical trapping and manipulation. A disk feature was included as part of the microtools and further functionalized by electron-beam deposition. The nanostructured gold layer on the disk facilitates off-resonant plasmonic heating upon illumination with a laser beam. As a consequence, natural convection characterized by the typical toroidal shape resembling that of Rayleigh–Bénard flow can be observed. A velocity of several μm·s−1 is measured for 2 μm microspheres dispersed in the surroundings of the microtool. To the best of our knowledge, this is the first time that thermoplasmonic-induced natural convection is experimentally demonstrated using a mobile heat source.

DOI

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