A submicron device to rectify a square-wave angular velocity
Institute for Advanced Studies in Basic Sciences (IASBS), P.O. Box 45195-1159, 45195, Zanjan, Iran
2 Department of Physics, University of Tehran, P.O. Box 14395-547, Tehran, Iran
Accepted: 18 January 2011
Published online: 16 February 2011
We study a system composed of two thick dielectric disks separated by a thin layer of an electrolyte solution. Initially both plates have the same surface charge distribution. The surface charge distribution has no rotational symmetry. We show that the top plate experiences a torque () if it rotates about its axis by an angle . The torque can be controlled by varying the electrolyte concentration, the separation and the surface charge density of the plates. For a specific example of charged rods attached to the plates, we find () sin(4) . We also study the dynamics of the system. We consider the case where the angular velocity of the bottom disk is a square-wave signal. We find that the average angular velocity of the top disk is not zero.
© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2011