Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 39: Colloids and Complex Liquids II - Dynamics and Mechanical Properties

CPP 39.4: Vortrag

Donnerstag, 17. März 2011, 11:15–11:30, ZEU 222

Self-Propelled Thermophoretic Motion of Gold Capped Microparticles — Andreas Bregulla¹, Markus Selmke¹, Ralf Seidel², Michael Mertig³, Klaus Kroy⁴, and •Frank Cichos¹ — ¹Molecular Nanophotonics Group, University Leipzig, Linnéstraße 5,04103 Leipzig — ²DNA Motors Group, BioTeC, University of Technology Dresden, Tatzberg 47-51, 01307 Dresden — ³Physikalische Chemie, Mess- und Sensortechnik, Technische Universität Dresden,Eisenstuckstr. 5 01069 Dresden — ⁴Soft Condensed Matter Theory Group, University Leipzig, Vor dem Hospitaltore 1, 04103 Leipzig

Molecular Motors are the machinery of cells that convert chemical into mechanical energy and transport material in a directed manner. Inspired by these molecular machines a number of different artificial self-propelled swimmers have been realized to mimic the same function for future applications in chip-sized laboratories. Most of these swimmers are, however, based on chemical reactions, which are difficult to control or to interrupt. Here we present the design and function of self-propelled microparticles, which can be addressed and switched externally by a laser field. The self-propelled motion is controlled by optical heating of a thin gold cap on polystyrene particles to generate a temperature gradient. The results on the directed motion of different sized particles provide strong evidence for a thermophoretic driving mechanism. Thus the presented particles provide for the first time a detailed control of the speed of each individual particle.