Despite nearly two centuries of study, the response of colloidal suspensions to electric fields can be ... when electrohydrodynamic forces due to constant applied fields compete with gravity.

Words are just too long sometimes. OK, let's get to this voltage thing. Imagine that you have a constant electric field near some object. You want to move an electron from point A to B as shown below.

The constant g—we call this the gravitational field. It's essentially the force per unit mass near the surface of Earth: Now let's do something similar with some electric charges. An electric ...