Manipulation devices based on magnetic forces, acoustic waves, hydrodynamic flows, light waves, or electrokinetic forces are among the major noninvasive technologies available today. Microfluidic devices exploiting hydrodynamic flows are suitable for cell population sorting, but have difficulties in trapping or controlling specific single objects. This chapter introduces a manipulation technology that is based on combining optical and electrokinetic principles, more specifically, optically induced electrokinetics (OEK) and its applications in manipulation and assembly of micro- and nanoscale entities. Two of the most attractive characteristics of OEK-based manipulation and assembly are operational flexibility and the operational mechanisms that are not restricted by the objects' electrical properties. The chapter presents the theory and operational principles of OEK devices and their major applications in cell trapping, cell sorting, optically induced electroporation, cell inherent properties' study, polymer thin film, and microor nanoparticles' manipulation and assembly by various OEK-based mechanisms.
