In the process of electrophoretic deposition (EPD), coatings are formed by forcing particles in solution toward an electrode with an electric field. After the particles reach the electrode surface, they move laterally to either aggregate into clusters or separate, depending on solution conditions and the frequency of the field. With dc electric fields the particles move together to form doublets and triplets, and then higher order clusters until a dense monolayer film is produced as more particles deposit. When the direction of the field is reversed for a partial monolayer, the particles separate. Experimental data verify that electroosmotic flow about each particle on the electrode entrains its neighbors, and a theory has been developed for two and three particle interactions. A similar phenomenon occurs with bubbles near surfaces. Two bubbles come together on a hot surface but move apart on a cold surface. Again, convection caused by a Marangoni flow about each bubble causes the motion. A theory based on this flow is able to predict the motion of the bubble pairs.