title: Rapid and selective concentration of microparticles in an optoelectrofluidic platform.
abstract: We demonstrate rapid manipulation and selective concentration of microparticles using AC electrokinetics such as dielectrophoresis (DEP) and AC electro-osmosis (ACEO) in an optoelectrofluidic platform based on a liquid crystal display (LCD). When 10 V bias at 10 kHz was applied to the optoelectrofluidic device, only the 1 microm-diameter polystyrene particles were concentrated into the projected LCD image patterns and closely packed, forming the crystalline structure by ACEO flow, while the 6 microm-diameter particles were repelled by negative DEP forces. We have characterized this frequency-dependency of the optoelectrofluidic particle behavior according to the particle diameter. On the basis of these results, we can rapidly concentrate the 1 microm-diameter particles and separate them from the 6 microm particles, by applying an AC signal of 10 kHz frequency. This novel technique can be applied to rapidly concentrate, separate and pattern micro-/nanoparticles in many biological and chemical applications.
authors.affiliation: Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Korea.
authors.forename: Hyundoo
authors.initials: H
authors.lastname: Hwang
authors.forename: Je-Kyun
authors.initials: JK
authors.lastname: Park
mesh_terms: D055664:Electrochemical Techniques; D004566:Electrodes; D007700:Kinetics; D050866:Liquid Crystals / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D011137:Polystyrenes