Orientation-controlled dielectrophoretic alignment of silicon microrod on a substrate with high positional accuracy

We demonstrate the orientation-controlled dielectrophoretic alignment of asymmetric Si microrods on a glass substrate with an asymmetric pair of electrodes. By applying AC bias to the electrodes, over 80% of the Si microrods align on the electrode pair so that a particular end of the microrod relates to a certain part of the electrode; the thick and thin ends overlap the thick and thin electrodes, respectively. Furthermore, the orientation of the top and bottom face of the Si microrod is also controllable when the thicknesses of the dielectric film on the top and bottom faces are different.