Selection of Brownian particles

  title={Selection of Brownian particles},
  author={Luc Pierre Faucheux and Albert Libchaber},
A macroscopic drift of Brownian particles (1.5 and 2.5 µm diameter silica spheres in water) is induced by switching on and off a spatially periodic asymmetric potential. It is defined by an ac voltage, applied between asymmetrically shaped metallic electrodes deposited on a glass plate. The induced drift is a function of the particle diffusion coefficient; one can thus select particles according to their size.