Biological applications of electrostatic surface field effects

This paper presents a few biological applications of surface field effects, including dielectrophoresis (DEP), electroosmotic flow (EOF) and liquid actuation. The stretch-and-positioning of DNA based on DEP enables the space-resolved observation of molecular interactions in single-molecule level, with its present application in gene location, and future application in DNA-based molecular constructions. Large genome DNA can be extended from a cell and placed on a chip with the use of EOF with variable flow direction. Electrostatic liquid actuation can be used for rapid transport and dispensing of nanoliter volume of liquids. Due to simplicity and compatibility with micro-fabrication, these surface field-effects are expected to provide convenient methodologies and tools for particle, molecule, and liquid manipulation in on-chip micro-biochemical systems.