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arXiv · 1010.0470

Active Motion of Janus Particle by Self-thermophoresis in Defocused Laser Beam

Hong-Ren Jiang·Natsuhiko Yoshinaga·Masaki Sano
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Abstract

We study self-propulsion of a half-metal coated colloidal particle under laser irradiation. The motion is caused by self-thermophoresis: i.e. absorption of laser at the metal-coated side of the particle creates local temperature gradient which in turn drives the particle by thermophoresis. To clarify the mechanism, temperature distribution and a thermal slip flow field around a micro-scale Janus particle are measured for the first time. With measured temperature drop across the particle, the speed of self-propulsion is corroborated with the prediction based on accessible parameters. As an application for driving micro-machine, a micro-rotor heat engine is demonstrated.

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Hong-Ren Jiang, Natsuhiko Yoshinaga, Masaki Sano. 2010-11-04. Active Motion of Janus Particle by Self-thermophoresis in Defocused Laser Beam. https://doi.org/10.1103/physrevlett.105.268302

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