Dong-Chul Han

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This paper presents a novel method for an on-chip erythrocyte deformability test under optical pressure, especially to enhance the level of sensitivity with respect to the detection of cancerous diseases. To demonstrate the performance and sensitivity of the combined method, we introduce the concept of transit velocity, a modified elongation index, and(More)
Transfection of DNA molecules into mammalian cells with electric pulsations, which is so-called electroporation, is a powerful and widely used method that can be directly applied to gene therapy. However, very little is known about the basic mechanisms of DNA transfer and cell response to the electric pulse. We developed a microelectroporation chip with(More)
Cervical spinal epidural abscess, caused by fish bone injury and a secondary infection by Eikenella corrodens which is part of the normal flora, has not been reported. A 72-yr-old man came to the hospital with pain in his posterior neck and both shoulders for 2 months. He also was experiencing weakness on his right side for 3 days. A fish bone had been(More)
This paper presents a novel way of designing a flow focusing channel for microchip flow cytometers. With this method we increased throughput and sensitivity of particle detection at the same time. Generally, to increase the detection throughput of a flow cytometer, the speed of the flow inside the focusing channel needs to be increased, hence reducing the(More)
A portable flow cytometer has been recognized as an important tool for many clinical applications such as HIV/AIDS screening in developing countries and regions with limited medical facilities and resources. Conventional flow cytometers typically require multiple detectors for simultaneous identification of multiple subsets of immune cell. To minimize the(More)
A new cylindrical capacitive sensor (CCS) design for the displacement measurement of precision active magnetic bearing (AMB) spindle is presented in this paper. This research is motivated by the problem that the existing 4-segment CCS is still sensitive to the third harmonic component of the geometric errors of a rotor. The procedure of designing a new CCS(More)
In this paper, we proposed a new measuring method of the speed-dependent tool tip compliance of a high-speed machine tool spindle using an AMB (active magnetic bearing). Single sine wave current excitation is injected through the AMB, and the displacement and force responses are measured with a CCS (cylindrical capacitance sensor) and a dynamometer,(More)
In this study the direct numerical method is applied to solve the perturbed Reynolds" equation. To solve it the perturbed dimensionless mass f low rate is used as the boundary condition under the inherently compensated restrictor. The dynamic characteristics of a rotor supported in the externally pressurized air bearings, such as stiffness and damping(More)