<title>Electrohydrodynamic propulsion for miniature ships</title>

Pumps utilizing electric traveling waves as the conveyor of liquids have already been presented in various publications. In those considerations, a dielectric liquid has been chosen as the media to propel. Inversely, it is conceivable to use pumps as propulsion motors for tiny vessels. Hereinafter, the proposed electrohydrodynamic (EHD) propulsion motor is based on the electric tube device which has been introduced in earlier papers by the first author for the tasks of particle mass transportation. The device is made by winding 6 parallel and insulated wires to a cylindrical tube. In the present work, the employed wires have a diameter in the range of 56 micrometers - 236 micrometers . Upon the application of multi-phase voltages to the monolayer-electrodes, the created traveling electric field wave carries the charged liquid in the same direction. Various EHD propulsion motors have been fabricated and optimized through a series of experiments. Optimizing parameters involve electrode- dimensions, fabrication materials, applied voltages and frequencies. As evaluative parameters, the propulsion pressure and the rate of liquid flow is determined. Constant and precise liquid propulsion is achieved. It is further shown that this tube structure has a high potential for miniaturization.