• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.977-978
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• 2011

• Molecular & Cellular Toxicology
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• v.2 no.4
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• pp.279-284
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• 2006

This paper describes the fabrication methods of a carbon nanotube (CNT) filter and a microdialysis chip. A CNT filter can help perform dialysis on a microfluidic chip. In this study, a membrane type of a CNT filter is fabricated and located in a microfluidic chip. The filter plays a role of a dialysis membrane in a microfluidic chip. In the fabrication process of a CNT filter, individual CNTs are entangled each other by amide bonding that is catalyzed by 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The chemically treated CNTs are shaped to form a CNT filter using a PDMS film-mold and vacuum filtering. Then, the CNT filter is sandwiched between PDMS substrates, and they are bonded together using a thin layer of PDMS prepolymer as adhesive. The PDMS substrates are fabricated to have a microchannel by standard photo-lithography technique.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.334-337
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• 2007

After the advent of micro-Total Analysis Systems(${\mu}-TAS$) based on silicon various polymer for microfluidic chip has been studied. Polymer materials for microfluidic compared with silicon and glass which were traditional materials of a microfluidic chip, have the advantages of economical efficiency simple manufacturing process and wide materials selectivity corresponding to fluids. Surface energy of polymers we, however lower than silicon or glass. To overcome this problem, various surface modification methods have been investigated. The surface modification using laser has the advantage of the simple experiment that only directly irradiated laser beam on the material surface in the air. This work discuss the surface modification of polymethly methacrylate(PMMA) by 4th harmonic Nd:YAG laser (${\lambda}266nm$, pulse) treatment. After the laser treatment, the PMMA surface was investigated using a contact angle measuring instrument. The contact angle was decreased with a increase of the surface oxygen content. This result means the surface energy of PMMA was increased by the laser treatment without changing of its bulk characteristics.

• Journal of Biomedical Engineering Research
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• v.34 no.4
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• pp.189-196
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• 2013

Dielectrophoresis(DEP) is useful in manipulation and separation of micro-sized particles including biological samples such as bacteria, blood cells, and cancer cells in a micro-fluidic device. Especially, those separation and manipulation techniques using DEP in combination of micro fabrication technique have been researched more and more. Recently, it is revealed that a window structure of insulating layer in microfluidic DEP chip is key role in trap of micro-particles around the window structure. However, the trap phenomenon-driven by DEP force gradient did not fully understand and is still illusive. In this study, we characterize the trap mechanism and efficiency with different shapes of window in a microfluidic DEP chip. To do this characterization, we fabricated 4 different windows shapes such as rhombus, circle, squares, and hexagon inside a micro-fluidic chip, and performed micro-sized particles manipulation experiments as varying the frequency and voltage of AC signal. Moreover, the numerical simulation with the same parameters that were used in the experiment was also performed in order to compare the simulation results and the experimental results. Those comparison shows that both results are closely matched. This study may be helpful in design and development of microfluidic DEP chip for trapping micro-scaled biological particle.

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.11a
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• pp.13.1-13.1
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• 2006

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.273-274
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• 2010

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.467-469
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• 2010

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1753-1756
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• 2010

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.86-92
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• 2004

In this paper miniaturized disposable micro/nanofluidic components applicable to bio chip, chemical analyzer and biomedical monitoring system, such as blood analysis, micro dosing system and cell experiment, etc are reported. This system includes various microfluidic components including a micropump, micromixer, DNA purification chip and single-cell assay chip. For low voltage and low power operation, a surface tension-driven micropump is presented, as well as a micromixer, which was implemented using MEMS technology, for efficient liquid mixing is also introduced. As bio-reactors, DNA purification and single-cell assay devices, for the extraction of pure DNA from liquid mixture or blood and for cellular engineering or high-throughput screening, respectively, are presented.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1688-1689
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• 2011

A simple and rapid capillary electrophoresis method was developed for the quantitative analysis of common triazine herbicides. Cyclic voltammetry was employed to clarify the detection voltage which showed characteristic irreversible cathodic peaks. For the analysis, the mixture of triazine herbicides was applied in a microfluidic chip to determine the CE-separated peaks. Soil sample extracts were analyzed directly after drying and redissolution with the supporting electrolyte but without other pretreatment. The results were comparable to those obtained by HPLC with UV detection. Therefore, this method can be used in the rapid determination of pesticide/herbicide residues.