Format

Send to

Choose Destination
Nature. 1994 Aug 11;370(6489):446-8.

Directional motion of brownian particles induced by a periodic asymmetric potential.

Author information

1
Centre de Recherche Paul Pascal, Pessac, France.

Abstract

Structures possessing spatial asymmetry should act as pumps in the presence of dissipation alone, without the need for macroscopic forces or temperature differences to drive vectorial motion. It has been shown theoretically that particles subjected to an asymmetric periodic potential can display net directional motion even if the space-averaged force is zero. Here we demonstrate such behaviour experimentally. We have studied the behaviour of colloidal particles suspended in solution and exposed to a sawtooth dielectric potential which is turned on and off periodically. The particles exhibit net motion with a velocity that depends on their size, suggesting applications in separation processes for objects in the size range 0.1-5 microns--a range that includes biological structures such as viruses, cells and chromosomes. We furthermore point out the analogy between our device and motor protein assemblies.

PMID:
8047163
DOI:
10.1038/370446a0
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center