Gorre-Talini L., Spatz J. P., Silberzan P.
Institut Curie, Section de Recherche-UMR IC/CNRS 168, 11, rue Pierre et Marie Curie-75231 Paris Cedex 05-France.
Chaos. 1998 Sep;8(3):650-656. doi: 10.1063/1.166347.
We have experimentally applied some concepts of "force-free" motion to micron size particles (latex beads). The coupling of dissipation and local spatial asymmetry of the potential experienced by the beads can put them into motion. The potentials used in these experiments are of dielectrophoretic nature. To that end, electrodes of particular shapes were used in order to submit the considered suspensions to inhomogeneous ac electric fields. Two regimes were explored: i-the Brownian ratchet case in which a Brownian particle is successively trapped in a factory roof-like potential and left free to diffuse. ii-the shifted ratchets case in which two potentials exhibiting similar characteristics are applied successively, one of them being shifted by a fraction of their common period relatively to the other. In both cases, a good agreement with the theoretical predictions was observed. In particular, particles of different sizes were characterized by different macroscopic velocities leading to the prospect of promising separation techniques. (c) 1998 American Institute of Physics.
我们已通过实验将一些“无外力”运动的概念应用于微米级粒子（乳胶珠）。珠子所经历的耗散与局部空间不对称势的耦合可使其运动起来。这些实验中使用的势具有介电泳性质。为此，使用了特定形状的电极，以便使所考虑的悬浮液受到非均匀交流电场的作用。研究了两种情况：i - 布朗棘轮情况，即布朗粒子先后被困在类似工厂屋顶的势中，然后自由扩散；ii - 位移棘轮情况，即先后施加两个具有相似特征的势，其中一个相对于另一个在其共同周期的一部分上发生了位移。在这两种情况下，均观察到与理论预测的良好一致性。特别是，不同尺寸的粒子具有不同的宏观速度，这为有前景的分离技术带来了希望。（c）1998美国物理研究所。
