• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1709-1714
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• 2007

It is demonstrated in this study that the nanoliter reactor arrays with an inkjet printing, can be used for high throughput screen of antibiotic function. As a model antibiotic, gramicidin was used in this study. The gramicidin embedded lipid vesicles were immobilized on the surface in the nanoliter reactor structure with control of the volume in the nanoliter reactor. By dispensing acidic drops into the reactor, the gramicidin function was monitored. The technique developed in this research also has a great potential to be used for discovery of drugs.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.731-732
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• 2008

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2004년도 Proceedings of 2004 Korea-Japan Joint Seminar on Particle Image Velocimetry
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• pp.141-145
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• 2004

Visualization and PIV measurements of the symmetrical recirculation flow in a nanoliter-sized droplet have been performed using the micro PIV system. The airflow sweeps over the nanoliter-sized liquid droplet fixed in a microchannel and the frictional force drags the liquid on the round interface, which causes the symmetrical recirculation flow in the droplet. The internal recirculation flow in the droplet has been visualized and measured successfully. The results of micro PIV measurement show the maximum speed of the recirculation flow is up to 10 mm/s. The high-speed recirculation can enhance a stirring effect and generate strong shear in the droplet, resulting in acceleration of mixing.

• 식품기술
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• 제23권2호
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• pp.205-211
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• 2010

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2004년도 International Symposium
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• pp.1-15
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• 2004

o Various microfluidic components including mixromixers and micropumps have been developed for disposable biochip applications. o Single cell capturing, positioning and nanoliter drug injection chip has been demostrated. o Multi-channel, two-dimensional micro-well array has been fabricated and cell capturing and specific reagent injection have been performed.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.834-834
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• 2005

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.146-153
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• 2006

A passive microfluidic delivery system using hydrophobic valving and pneumatic control was devised for microfluidic handling on a chip. The microfluidic metering, cutting, transport, and merging of two liquids on the chip were correctly performed. The error range of the accuracy of microfluid metering was below 4% on a 20 nL scale, which showed that microfluid was easily manipulated with the desired volume on a chip. For a study of the feasibility of biochemical reactions on the chip, a single enzymatic reaction, such as ${\beta}-galactosidase$ reaction, was performed. The detection limit of the substrate, i.e. fluorescein $di-{\beta}-galactopyranoside$ (FDG) of the ${\beta}-galactosidase$ (6.7 fM), was about 76 pM. Additionally, multiple biochemical reactions such as in vitro protein synthesis of enhanced green fluorescence protein (EGFP) were successfully demonstrated at the nanoliter scale, which suggests that our microfluidic chip can be applied not only to miniaturization of various biochemical reactions, but also to development of the microfluidic biochemical reaction system requiring a precise nano-scale control.

• 한국정밀공학회지
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• 제29권8호
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• pp.913-919
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• 2012

This paper presents results for dispensing and measuring micro-particles using a pneumatic dispensing system. Particle-suspended liquid droplets were dispensed and analyzed quantitatively at various particle concentrations and applied pressures. By using a developed experimental setup, the number of particles and the particle volume ratio in sequentially dispensed droplets were measured. Hydrophilic and hydrophobic surfaces were tested to find a suitable surface for counting the number of particle. It was confirmed that the dispensed particles concentrated into the center of the droplet on the smooth CD surface after evaporation of liquid. As the applied positive pressure increased, the number of particles per droplet increased consistently and the volume fraction of particles remained constant.

• 대한기계학회논문집B
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• 제33권3호
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• pp.178-185
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• 2009

Simple and highly efficient droplet merging method is proposed, which enables two nanoliter or picoliter droplets to merge regularly in a straight microchannel. Using a cross channel with inflows of one oil phase through the main channel and two water phases through the side channels, two droplets of different sizes can be generated alternatingly in accordance with flow rate difference of the water phases. It is shown that for a fixed oil phase flow rate, the flow rate of one water phase required for alternating droplet generation increases linearly with the flow rate of another water phase. By this method, the droplets are merged with 100 % efficiency without any additional driving forces.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1752-1757
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• 2008

Simple and highly efficient droplet merging method is proposed, which enables two nanoliter or picoliter droplets to merge regularly in a straight microchannel. We observe that two droplets of the same size but of different viscosities are merged by velocity difference induced as they are transported with the carrier fluid. To make viscosity difference, the mass ratio of water and glycerol is varied. Two droplets of the same size or of different sizes are generated alternatingly in the cross channel by controlling flowrates. This droplet merging method can be used to mix or encapsulate one target sample with another material, so that it can be applied to cell lysis, particle synthesis, drug discovery, hydrogel-bead production, and so on.