• Journal of the KSME
• /
• v.50 no.11
• /
• pp.35-38
• /
• 2010

이 글에서는 줄기세포 연구의 중요성과 마이크로 미세유체칩에서 줄기세포의 거동을 연구한 선행 연구 사례들을 소개하고자한다.

• Journal of the KSME
• /
• v.57 no.10
• /
• pp.43-47
• /
• 2017

이 글에서는 이온농도분극 현상(ICP : Ion Concentration Polarization)을 활용하여 단백질과 같은 생체물질을 농축하는 종이기반의 미세유체칩에 대하여 소개하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.5
• /
• pp.437-441
• /
• 2014

This paper presents a novel microplatform for high power generation based on reverse electrodialysis. The ideal cation-selective membrane for power generation was realized using geometrically controlled in situ self-assembled nanoparticles. Our proposed membranes can be constructed through a simple and cost-effective process that uses microdroplet control with nanoparticles in a microchannel. Another advantage of our system is that the maximum power and energy conversion efficiency can be improved by changing the geometry of the microchannel and proper selection of the nanoparticle size and material. This proposed platform can be used to supply power sources to other microdevices and contribute to a fundamental understanding of ion transport behavior and the power generation mechanism.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.1
• /
• pp.89-95
• /
• 2012

In this paper, microchannels for the flow control of two fluids with different volumes have been designed, fabricated, and verified. The dimensions of the inlets were determined based on the Stokes equation in order to realize that the flow of the two fluids meet at the same time, and to maintain a certain configuration when the flows passed through each inlet channel. The designed microchannels were confirmed using computational fluid dynamics simulation for the incompressible, Newtonian, and transient flows. In addition, a microfluidic system containing the designed microchannels was fabricated by soft lithography, and the pressure-driven flows of the two fluids were characterized by microfluidic experiments.

• Journal of the Korean Society of Visualization
• /
• v.18 no.3
• /
• pp.84-89
• /
• 2020

Cancer cells secrete angiogenic factors, and nearby vasculatures make new blood vessels essential for cancer development and metastasis in response to these soluble factors. Many efforts have been made to elucidate cancer-endothelial cell interactions in vitro. However, not much is known due to the lack of a suitable co-culture platform. Here, we introduce a 3D printing-based microfluidic system that mimics the in vivo-like cancer-endothelial cell interactions. The tumoroids and endothelial cells are co-cultured, physically separated by porous fibrin gel, allowing communication between two cell types through soluble factors. Using this microfluidic system, we were able to visualize new vessel formation induced by tumoroids of different origins, including liver, breast, and ovary. We confirmed that the ovarian tumoroids most induced angiogenesis while the other two cancer types suppressed it. Utilization of the proposed co-culture platform will help the researchers unveil the underlying mechanisms of the dynamic interplay between tumor and angiogenesis.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.12
• /
• pp.1159-1165
• /
• 2013

Powder blasting, which is an efficient micromachining method for glass, silicon, and ceramics, has a critical disadvantage in that the surface finish is poor owing to the brittle fracture of materials. Low-pressure waterjet machining can be applied to smoothen the rough surface inside the blasted structure. In this study, the surface roughness and sectional dimension of micro-channels are observed during the repetitive application of a waterjet to blasted micro-channels. The asperities and subsurface cracks created by blasting are removed by waterjet machining. Along with the surface roughness, it is found that the sectional dimension increases and the edges of the finished micro-channel become slightly round. Finally, a microfluidic chip is machined by the blasting-waterjet process and a transparent microfluidic channel is obtained efficiently.

• Korean Journal of Microbiology
• /
• v.53 no.2
• /
• pp.71-78
• /
• 2017

Raman microspectroscopy is a promising tool for microbial analysis at single cell level since it can rapidly measure the cell materials including lipids, nucleic acids, and proteins by measuring the inelastic scattering of a molecule irradiated by monochromatic lights. Using Raman spectra provides high specificity and sensitivity in classification of bacteria at the strain level. In addition, a Raman approach coupled with stabled isotope such as $^{13}C$ and $^2H$ is able to detect and quantify general metabolic activity at single cell level. After bacterial detection process by Raman microspectroscopy, interested unculturable cell sorting and single cell genomics can be accomplished by combination with optical tweezer and microfluidic devices. In this review, the characteristics and applications of Raman microspectroscopy were reviewed and summarized in order to provide a better understanding of microbial analysis using Raman spectroscopy.