Here’s an interesting effect discovered by a group of Iranian physicists at Sharif University of Technology in Tehran, Iran (it’s not often we hear from these guys).
They placed a thin film of water in a square cell and applied two perpendicular electric fields. One was an external electric field. For the other, they used two copper electrodes to generate a voltage across the cell like an electrolysing cell (although no chemical reaction took place).
So they had a pair of electric fields at right angles acting on this thin film. The unexpected result is that the film of water begins to rotate. The team has a number of movies of the effect on its website. They call it a liquid film motor and it’s a quite extraordinary effect. At one point they divide their cell into nine smaller ones and the liquid in each cell rotates in exactly the same way.