title: Development of a new contactless dielectrophoresis system for active particle manipulation using movable liquid electrodes.
abstract: This study presents a new DEP manipulation technique using a movable liquid electrode, which allows manipulation of particles by actively controlling the locations of electrodes and applying on-off electric input signals. This DEP system consists of mercury as a movable liquid electrode, indium tin oxide (ITO)-coated glass, SU-8-based microchannels for electrode passages, and a PDMS medium chamber. A simple squeezing method was introduced to build a thin PDMS layer at the bottom of the medium chamber to create a contactless DEP system. To determine the operating conditions, the DEP force and the friction force were analytically compared for a single cell. In addition, an appropriate frequency range for effective DEP manipulation was chosen based on an estimation of the Clausius-Mossotti factor and the effective complex permittivity of the yeast cell using the concentric shell model. With this system, we demonstrated the active manipulation of yeast cells, and measured the collection efficiency and the dielectrophoretic velocity of cells for different AC electric field strengths and applied frequencies. The experimental results showed that the maximum collection efficiency reached was approximately 90%, and the dielectrophoretic velocity increased with increasing frequency and attained the maximum value of 10.85 ± 0.95 μm/s at 100 kHz, above which it decreased.
authors.affiliation: School of Mechanical Engineering, Chung-Ang University, Heuksuk-dong, Dongjak-gu, Seoul, Korea.
authors.forename: Hyuk Rok
authors.initials: HR
authors.lastname: Gwon
authors.forename: Suk Tai
authors.initials: ST
authors.lastname: Chang
authors.forename: Chang Kyoung
authors.initials: CK
authors.lastname: Choi
authors.forename: Jung-Yeul
authors.initials: JY
authors.lastname: Jung
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Seong Hyuk
authors.initials: SH
authors.lastname: Lee
mesh_terms: D004129:Dimethylpolysiloxanes; D004566:Electrodes; D004586:Electrophoresis / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D009757:Nylons
chemical_list: D004129:Dimethylpolysiloxanes; D009757:Nylons; C085707:poly(dimethylsiloxane)-polyamide copolymer
keywords: Active particle manipulation; Contactless dielectrophoresis; Movable liquid electrode