DIELECTROPHORETIC RATCHETS

Citation
L. Gorretalini et al., DIELECTROPHORETIC RATCHETS, Chaos (Woodbury, N.Y.), 8(3), 1998, pp. 650-656
Citations number
20
Categorie Soggetti
Mathematics,"Physycs, Mathematical",Mathematics
Journal title
ISSN journal
10541500
Volume
8
Issue
3
Year of publication
1998
Pages
650 - 656
Database
ISI
SICI code
1054-1500(1998)8:3<650:>2.0.ZU;2-O
Abstract
We have experimentally applied some concepts of ''force-free'' motion to micron size particles (latex beads). The coupling of dissipation an d local spatial asymmetry of the potential experienced by the beads ca n put them into motion. The potentials used in these experiments are o f dielectrophoretic nature. To that end, electrodes of particular shap es were used in order to submit the considered suspensions to inhomoge neous ac electric fields. Two regimes were explored: i-the Brownian ra tchet case in which a Brownian particle is successively trapped in a f actory roof-like potential and left ii-ee to diffuse. ii-the shifted r atchets case in which two potentials exhibiting similar characteristic s are applied successively, one of them being shifted by a fraction of their common period relatively to the other. In both cases, a good ag reement with the theoretical predictions was observed. In particular, particles of different sizes were characterized by different macroscop ic velocities leading to the prospect of promising separation techniqu es. (C) 1998 American Institute of Physics.