Particle focusing in a contactless dielectrophoretic microfluidic chip with insulating structures

Chun Ping Jen, Hsin Yuan Shih, Yung-Chun Lee, Fei Bin Hsiao

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The main purpose of the present study was to investigate the feasibility of applying the technique of contactless dielectrophoresis (cDEP) on an insulator-based dielectrophoretic (iDEP) microdevice with effective focusing of particles. The particles were introduced into the microchannel and pre-confined hydrodynamically by the funnel-shaped insulating structures close to the inlet. The particles were, therefore, repelled toward the center of the microchannel by the negative dielectrophoretic forces generated by the insulating structures. The microchip was fabricated by the technique of cDEP. The electric field in the main microchannel was generated by using electrodes inserted into two conductive micro-reservoirs, which were separated from the main microchannel by thin insulating barriers made of 20 μm-width of PDMS. The impedance of the PDMS barrier under different frequencies was measured by an impedance analyzer and the fitting curve to experimental data using the least-squares method were also addressed. The results revealed the capacitive behavior of the PDMS, in which the impedance decreased with the frequency. The numerical simulations indicated that an increase in the strength of the applied electric field significantly enhanced the performance of focusing. The preliminary experiments employing latex particles with 10 μm in diameter were conducted to demonstrate the feasibility of the present design. The usage of contactless DEP technique makes the insulator-based dielectrophoretic microchip mechanically robust and chemically inert. Furthermore, the voltage applied was also reduced rather than conventional iDEP microchip.

Original languageEnglish
Title of host publicationDTIP 2011 - Symposium on Design, Test, Integration and Packaging of MEMS/MOEMS
Pages362-365
Number of pages4
Publication statusPublished - 2011 Dec 1
Event2011 Symposium on Design, Test, Integration and Packaging of MEMS/MOEMS, DTIP 2011 - Aix-en-Provence, France
Duration: 2011 May 112011 May 13

Publication series

NameDTIP 2011 - Symposium on Design, Test, Integration and Packaging of MEMS/MOEMS

Other

Other2011 Symposium on Design, Test, Integration and Packaging of MEMS/MOEMS, DTIP 2011
Country/TerritoryFrance
CityAix-en-Provence
Period11-05-1111-05-13

All Science Journal Classification (ASJC) codes

  • Hardware and Architecture

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