Kwon T.H. – TechConnect Briefs

Replication of nano dimple structures by injection molding with rapid thermal control system

Rha M., Park J.M., Kwon T.H., Pohang University of Science and Technology, KR

The present study proposes an efficient and easy mass production method for nano dimple structures by injection molding. Anodic aluminum oxide (AAO) technique is utilized to make a master with nano dimple structures, and then [...]

Replication of micro/nano combined structure using micro/nano combined aluminum stamp

Cha K.J., Kwon T.H., POSTECH, KR

This paper presents an easy and efficient fabrication method of plastic replicas of micro/nano combined structures using an aluminum stamp with micro/nano combined structures (ASMNCS) on its surface. ASMNCS could be fabricated by two steps: [...]

Chaotic mixing using periodic and aperiodic sequences of mixing protocols in a micromixer

Kang T.G., Singh M.K., Kwon T.H., Anderson P.D., Eindhoven University of Technology, NL

We conducted a numerical study on mixing in a barrier embedded micromixer with an emphasis on the effect of periodic and aperiodic sequences of mixing protocols on mixing performance. A mapping method was employed to [...]

Intrinsic Effects of Materials on Superhydrophobicity of Polymer Replicas from Nature

Lee S.M., Kwon T.H., Pohang University Science and Technology, KR

The present work suggests a mass-producible and large scale fabrication method of superhydrophobic polymeric surfaces by means of material processing equipments which can maximize productivity and cost effectiveness. We fabricated two types of polymeric lotus [...]

Replication of Highly-Hydrophobic Surface with Micro/Nano Combined Structures from Nature

Lee S.M., Kwon T.H., Pohang University of Science and Technology, KR

A highly-hydrophobic film has successfully been fabricated by simply replicating plant leaf surface with micro/nano combined structures. A plant leaf was used as a master to make a mold by nickel electroforming. The positive polymer [...]

Magnetohydrodynamic (MHD) Complex Flow Generation in Microchannel

Kim D.S., Kwon T.H., Pohang University of Science and Technology (POSTECH), KR

In this paper, we present design methodologies for magnetohydrodynamic (MHD) complex flow generation in a simple straight microchannel in which electrodes are patterned on two side walls and bottom wall. The required applied voltage conditions [...]

Fabrication of Hydrophobic Film using Plant Leaves from Nature

Lee H.S., Lee S.M., Lee H.S., Lee S.M., Kwon T.H., Pohang University of Science and Technology, KR

In this study, we have attempted to reproduce the hydrophobic characteristics of plant leaves from nature by replicating the micro/nano feature of leaf surface in UV embossed film. The contact angle (CA) of the replicated [...]

Modeling, Analysis and Design of Centrifugal Force Driven Transient Filling Flow into Rectangular Microchannel

Kim D.S., Kwon T.H., Pohang University of Science and Technology, KR

In this paper, we first present successful modeling and analysis results of a centrifugal force driven transient filling flow into a rectangular microchannel. Two types of exact and pseudo-static approximate solutions were derived for the [...]

Numerical Visualization and Quantification of Chaotic Mixing for Micromixers

Kang T.G., Kwon T.H., Pohang University of Science and Technology, KR

We present a systematic way of visualization and quantification of mixing in chaotic micromixers with a periodic mixing protocol. We name it colored particle tracking method, which consists of three steps. One is flow analysis [...]

Prediction Model of Microlens Fabricated by Modified LIGA Process

Kim D.S., Lee S-K, Lee S.S., Yang S.S., Kwon T.H., Lee S-K, Lee S.S., Pohang University of Science and Technology, KR

In this paper, we present a prediction model for microlens formation by means of a deep X-ray lithography followed by a thermal treatment of a PMMA (Polymethyl-methacrylate) sheet. According to this modeling, X-ray irradiation causes [...]