Surface charges as a versatile platform for emerging applications.

Surface charges are ubiquitous in nature and their existence is in many forms. Due to an unbalanced electrical force induced by surface charge gradient, the droplet self-propels towards the direction of larger surface charge density. In 2008, Liu and Bard [11] reported the surface charge on the dielectric material can be used as a redox reagent to drive chemical reaction. [Extracted from the article]