Regensburg 2013 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 41: Colloids and Complex Liquids I
CPP 41.2: Vortrag
Donnerstag, 14. März 2013, 10:00–10:15, H40
Individually tunable Micromachines driven by laser induced self propelled thermophoresis — •Andreas Bregulla1, Bian Qian2, Haw Yang2, and Frank Cichos1 — 1Universitiy of Leipzig, Germany — 2Princeton University
Trapping and guiding individual micro- or nano-objects in solution by optical means is one important task for nanotechnology. Living cells have developed strategies to transport objects with the help of molecular motors. Thus combining active motion with optical control may deliver new pathways for micro and nanomanipulation. Here we present a new concept based on self-thermophoretic action. A particle which is capped by a thin metal layer is heated by an laser beam causing a temperature gradient along the particle surface. This temperature gradient leads to a directed thermophoretic propulsion of the particle. This directed motion, however, is randomized by rotational Brownian motion and just enhanced the diffusive motion on a large timescale. To overcome this randomizing a stochastic feedback mechanism can be developed, which employs the rotational Brownian motion to suppress their action. This method can be extended to the control of multiple individual particles on independent pathways and provides numerous new perspectives for nano-manipulations in liquids.