Send to

Choose Destination
Phys Rev Lett. 2010 Dec 31;105(26):268302. Epub 2010 Dec 20.

Active motion of a Janus particle by self-thermophoresis in a defocused laser beam.

Author information

Department of Physics, The University of Tokyo, Tokyo, Japan.


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 a 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 microscale 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 a micromachine, a microrotor is demonstrated.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for American Physical Society
Loading ...
Support Center