• KSBB Journal
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• v.24 no.6
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• pp.515-520
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• 2009

This study presented facile method of cell patterning using fabricated PDMS patterns on polyelectrolyte coated surface. This basic principle is the fabrication of functional surface presenting two orthogonal surfaces such as cell adhesive and repellent properties. Cell adhesive surface was firstly fabricated with simple coating of polyelectrolyte multilayer. And then, the desired patterns of PDMS for the prevention of nonspecific binding of cells were transferred onto the previously formed thin film of polyelectrolyte multilayer. Thus, we could prepare novel functional surface simultaneously containing PDMS and polyelectrolyte region. As expected, the PDMS regions showed effective prevention of nonspecific binding of cell and the other region, exposed polyelectrolyte area, provided cell adhesive environment. The height of formed PDMS structure was about 100 nm. Based on this method, cell patterning can be successfully obtained with various pattern shapes and sizes. Therefore, we expect that this simple method will be useful platform technology for the development of cell chip, cell based assay system, and biochip.

• Journal of the Korean Vacuum Society
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• v.16 no.1
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• pp.65-73
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• 2007

The control of surface properties and spatial presentation of functional molecules within a microfluidic channel is important for the development of diagnostic assays, microreactors, and for performing fundamental studies of cell biology and fluid mechanics. Here, we present soft lithographic methods to create robust microchannels with patterned microstructures inside the channel. The patterned regions were protected from oxygen plasma by controlling the dimensions of the poly(dimethylsiloxane)(PDMS) mold as well as the sequence of fabrication steps. The approach was used to pattern a non-biofouling polyethylene glycol(PEG)-based copolymer or the polysaccharide hyaluronic acid(HA) within microfluidic channels. These non-biofouling patterns were then used to fabricate arrays of fibronectin(FN) and bovine serum albumin(BSA) as well as mammalian cells.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.104.2-104.2
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• 2011

세계적으로 환경오염이 심각해짐에 따라 친환경적으로 에너지를 생산하는 기술이 주목받고 있다. 그 중에서도 태양광을 이용하여 전력을 생산하는 태양광 태양전지의 경우 원리가 간단하고 에너지원의 수급이 용이하다는 장점으로 인하여 많은 연구가 진행되고 있다. 그러나 태양광 태양전지의 경우, 태양전지 기판에서의 반사로 인하여 발전 효율이 낮아는 문제점이 있다. 이를 해결하기 위해 텍스처링 공정을 통해 태양전지 기판에서의 반사를 줄이고 태양전지의 효율을 증가시키는 방법이 이용되고 있다. 본 연구에서는 나노 돌기를 가진 저반사 패턴을 이용하여 태양전지용 실리콘 기판을 제작함으로써, 태양전지 기판에서의 반사를 줄이고자 하였다. 나노 돌기를 가진 저반사 패턴이 형성 된 태양전지용 실리콘 기판을 제작하기 위해 ICP 장비를 이용한 $Cl_2$ 플라즈마 식각공정을 진행하였다. 먼저 Au agglomeration 기술을 이용하여 Au nano particle을 실리콘 기판 위에 형성 후, 이를 식각 마스크로 이용하여 ICP 식각을 진행하였다. 이어서 나노 돌기가 형성 된 실리콘 기판 위에 $Cl_2$ 플라즈마에 내식각성이 우수한 레지스트를 이용하여, 나노 임프린트 리소그래피 기술을 통해 저반사 패턴을 형성하였다. 이 방법으로 형성 된 저반사 패턴을 식각 마스크로 사용하여 앞의 공정과 동일한 조건으로 실리콘 기판을 식각하였다. 최종적으로 agglomerated Au particle과 $Cl_2$ 플라즈마에 내식각성이 우수한 레지스트를 이용하여 나노 돌기를 가진 저반사 패턴이 형성된 실리콘 기판을 제작하였다.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.390-394
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• 2019

This paper presents an inkjet-printed plastic force sensor using PEDOT:PSS. Using a piezoelectric-type inkjet printer, the force sensor was manufactured by printing PEDOT:PSS ink onto a polyimide (PI) substrate film. Applying a vertical force of 0 to 100 N to the force sensor on the PI substrate with a thickness of 64 mm, the resistance of the force sensor increased in proportion to the input force by the length deformation of the PI substrates and the sensor pattern. As a result, the fabricated sensor has a characteristic of 0.001% /N with a linearity of 99.38%. In addition, as the thickness of the PI substrate film increased, the sensitivity of the sensor increased linearly. The fabricated force sensor is expected to be applied to industrial sites and healthcare fields.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.141-144
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• 2006

An antibody layer was fabricated to detect Escherichia coli O157:H7. The micropattern of 16-mercaptohexadecanoic acid (16-MHDA) as alkylthiolate was formed on the gold surface by using the PDMS stamp with microcontact printing $({\mu}CP)$ techniques. In order to form antibody patterns on the template, protein G was chemically bound to the 16-MHDA patterns, and antibody was adsorbed on a self-assembled protein G layer. The formation of the 16-MHDA micropattern, self-assembled protein G layer and antibody pattern on Au substrate was confirmed by surface plasmon resonance (SPR) spectroscopy. Finally, the micropatterning method was applied to fabricate the antibody probe for detection of E. coli O157:H7, and monitoring of antigen by using this probe was successfully achieved.

• Journal of Fashion Business
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• v.17 no.3
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• pp.30-47
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• 2013

In the modern fashion industry, efficiency has been increasing thanks to development of computer graphics, IT technology, and digitalization. Unlike the past when fashion design heavily depended on handwork, digitalization of fashion industry makes fabrication time shorter and enables designers to adopt comprehensive expression, generating high value-added product. The Apparel CAD, an example of the digitalized fashion industry, has been developed from 2D system into a system providing 3D simulation. Digital clothing can be determined as an activity of designers using the tool in order to fabricate pattern and simulate its designed clothes in the virtual space of computer. In this study, physical properties of eight materials, which can be utilized on a par with current fashion trend, have been specified. For more sophisticated investigation, external appearance of the material was investigated by 3D scanning. In order to examine the physical properties of fabric specimens, KES(Kawabata Evaluation System) measurements and other physical property measurements were made. With the results, virtual material and clothes were simulated via CLO 3D, one of 3D apparel CAD systems. Then, virtual fabrics and clothes of similar types were generated and analyzed.

• Journal of Biomedical Engineering Research
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• v.35 no.6
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• pp.192-196
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• 2014

Collagen scaffolds were synthesized by cross linking into a solution mixture of 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochlorid(EDC) in ethanol, followed by pressing, cleaning and lyophilization process after the type I atelo-collagen solutions in D.I water(pH3). The experimental conditions are collagen concentration of 1.0 wt%, 3.0 wt%, 5.0 wt% and differential concentration of cross-linker. Then, parametric studies were performed by varying the parameters to investigate the morphology, the porosity, the swelling ratio and the thickness and genotoxicity of the scaffolds. The scaffolds thickness pattern was regular to concentration of the degree of cross-linker and collagen. It was observed that the swelling ratio, the degree of crosslink, and the pore size(thickness of scaffold) can be controlled by adjusting the collagen, crosslinker. Among the parameters investigated, the smallest thickness can be achieved by collagen, crosslinker concentrate condition. The collagen scaffold is induced no genotoxicity. The lowest swelling ratio, as an indication of the highest degree of crosslink, can be obtained by adding crosslink agent.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.580-583
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• 2007

In this paper, we proposed a slot antenna for dual band ISM that was transformed from a slot antenna structure. Proposed antenna was designed and fabricated that transformed feed line was changed existing slot antenna feed line to appear resonances at dual band. Bandwidth of the designed and fabricated slot antenna for ISM dual band is 8.23%, 4.8% at the resonated frequency at 2.45 GHz, 5 GHz. And we observed the resonant frequency and bandwidth according to change of feed line and slot length. Also, the measured radiation pattern characteristic of fabricated antenna is compared and analyzed E-plane and H-plane at 2.45 GHz, 5GHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.901-904
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• 2001

For the c-axis oriented epitaxial YBa$_2$Cu$_3$O$_{7-{\delta}}$ thin film on r-cut sapphire substrate it is necessary to deposit buffer layers. The CeO$_2$buffer layer was deposited on sapphire substrate using RF magnetron sputtering system. We investigated XRD pattern of CeO$_2$thin films at various sputtering conditions such as sputtering gas ratio, sputtering power, target to substrate distance, sputtering pressure and substrate temperature. The optimum condition was 15 mTorr with deposition pressure, 1:1.2 with $O_2$and Ar ratio and 9cm with target to substrate distance. The CeO$_2$(200) peak was notable for a deposition temperature above 75$0^{\circ}C$. The YBa$_2$Cu$_3$O$_{7-{\delta}}$ was deposited on CeO$_2$buffered r-cut sapphire substrate using pulsed laser ablation. The YBa$_2$Cu$_3$O$_{7-{\delta}}$CeO$_2$(200)/A1$_2$O$_3$thin film was exhibited a critical temperature of 89K.xhibited a critical temperature of 89K.

• Transactions on Electrical and Electronic Materials
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• v.4 no.4
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• pp.22-25
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• 2003

High series resistance due to the presence of glass frit is one of the major problems for screen printed silicon solar cells. Cells having electrical parameters below the prescribed values are usually rejected during solar module fabrication. Therefore, it is highly desirable to improve the electrical parameters of the silicon solar cells and thereby to increase the overall production yield. It was observed that, the performance of low quality mono-crystalline silicon solar cells made by standard screen printing technology could be improved remarkably by novel surface treatment. We have chemically treated the surface using sodium hydroxide (NaOH) and silver nitrate ($AgNO_3$) solutions. NaOH treatment helps to reduce the series resistance by decreasing the presence of excess glass frit on the top silver grid contact. The $AgNO_3$ treatment is used to reduce the series resistance comes from the deposition of silver on the grids by filling the holes present (if any) within the grid pattern.