  We report on electrically-induced rotations in water films, which can
function at many length scales. The device consists of a two-dimensional cell
used for electrolysis of water films, as simple as an insulator frame with two
electrodes on the sides, to which an external in-plane electric field
perpendicular to the mean electrolysis current density is applied. If either
the external field or the electrolysis current exceeds some threshold (while
the other one is not zero), the liquid film begins to rotate.
