• BMB Reports
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• v.49 no.12
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• pp.655-661
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• 2016

Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate's properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.

• KSTLE International Journal
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• v.2 no.1
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• pp.22-28
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• 2001

A resin bonded copper-graphite brush was investigated to evaluate the characteristics electrical signal transmission through a sliding contact as a function of the relative amount of graphite and copper in the brush. Particular attention was given to the correlation between electrical signal fluctuation and tribological properties in an electrical sliding contact system. A ring-on-block type tribotester was used for this experiment and the ring was made from pure copper. Results showed that a copper-graphite brush at a particular composition range exhibited the most stable frictional behavior with a minimum voltage drop. The amount of voltage drop at the friction interface was affected by the surface roughness, transfer film formation at the friction interface, and the real area of contact. Microscopic observations and the surface analysis showed a good agreement with the results from this experiment. The results also indicated that the electrical signal flunctuation was directly associated with the oscillation of the coefficient of friction during sliding by nanoscale variation of contacts at the friction interface.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.596-596
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• 2013

본 연구에서는 Carbon nanotube 용액을 brush-painting 시스템을 이용하여 유연성 있는 PET 기판 위에 고품위의 플렉시블 투명전극을 제작하였다. CNT 박막의 두께에 따른 특성을 알아보기 위해 brushing 횟수를 증가시켜 UV/Vis Spectrometry, four-point probe 및 Hall measurement를 이용하여 전기적, 광학적특성을 알아보았다. 최적조건인 bilayer의 CNT 박막은 244 Ohm/sq.의 면 저항과 550 nm에서 68％의 투과도를 얻을 수 있었다. CNT 박막의 기계적 응력에 따른 전기적 안정성을 알아보기 위해 bending test를 진행하였다. 10,000번 구부려도 저항의 변화가 거의 없어 이 박막이 플렉시블한 소자에 적합하다는 것을 알았다. 유기태양전지의 적용 가능성을 알아보기 위해 CNT 박막을 유기태양전지의 anode 층으로 적용하여 1.6％ (VOC: 0.566(V), $J_{SC}$: 7.118(mA/$cm^2$), Fill Factor: 40.49(％))의 효율을 얻어 유기태양전지 소자의 적용 가능성을 알았다. 최종적으로 실험에서 성막된 CNT 박막은 기존의 CVD공정과 같은 복잡한 공정 대신에 쉽고 간편하게 고품위의 flexible brush-painting Carbon nanotube (CNT) 투명전극을 제작 하여 플렉시블한 유기태양전지 소자의 가능성을 알아보았다.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.343-343
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• 2006

Surface-initiated atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) was carried out to produce high-density poly(MPC) brush on silicon wafer. Frictional properties of poly(MPC) was investigated by by sliding a glass ball (${\phi}\;10\;nm$) on the substrates over a distance of 20 mm at a sliding velocity of 90 mm/min under loading of 0.49 N at 298 K. Higher friction coefficients were observed in dry N2 atmosphere and in toluene condition, whereas the friction coefficients decreased to 0.02 in humid air and in water. It is supposed that water-swollen poly(MPC) brush works as a lubricant to moderate the interaction between brush and probe.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.6
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• pp.867-877
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• 1998

The purpose of this study was to investigate the ideal locations and dimensions of bristles for the patients who were installed with fixed prostheses and severely involved periodontitis. The models of 16 pts were analysed and the resullts were as follows: 1. There were no tooth brushes in the market, which were proper for the patients who were installed with fixed prostheses and had severely periodontally involved teeth. 2. The neck portion of the tooth brush should be narrow as possblly. 3. The size of tooth brush should be analyzed by the size of arch. 4. The width of tooth brush should be analyzed by the degree of bone recession. 5. The custom made tooth brush may be ideal, if possible.

• Journal of the Korea Computer Graphics Society
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• v.8 no.1
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• pp.21-28
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• 2002

This paper presents a brush stroke direction creation method to distill painterly expressions from picture images. In actual paintings, each brush stroke has the same directionality in one segmented area. but directionality changes in the area of image border edges. This study employed the following methods to implement the directionality of the brush stroke area by: (1) detecting edge in input images, (2) region splitting and merging based on quad-tree division method, and (3) composing a direction map to create brush strokes with the same directionality in the segmented area. The results of the implementation enabled the simulation of the directionality of the stroke area shown in actual paintings.

• Journal of Environmental Science International
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• v.26 no.2
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• pp.201-210
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• 2017

This study was conducted to estimate the removal efficiency of algae by a mechanical Screw Brush Cone Filter in a lake. The device used a stainless steel cone-shaped filter with a screw brush. The ability of the developed device to remove algae larger than $20{\mu}m$ in Lake ChaSa, Gwangyang city was tested from August to September 2014. The results show that the removal rates for chlorophyll-a, suspended solids and volatile suspended solids were 44-87%(mean 61%), 35-54%(mean 40%), and 37-46%(mean 43%), respectively. This study also discusses equipment and device operation costs and device application problems, and suggests in situ. solutions to these problems.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.394-400
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• 2012

Due to the increasing demand for carious methodologies, the quality improvement of products were introduced. A brush, the most frequently used type of grinding process, is one of the deburring. In order to produce consistent burr shape, various machining conditions have been combined and applied to disk grinding process. By tool dynamometer, acoustic emission sensor and acceleration sensor depend on changes in processing conditions(depth of engagement, cutting speed, workpiece position, workpiece orientation, cutting time) signals were obtained for brush deburring grinding system. Root mean square obtained by processing the signal processing conditions by analyzing the characteristics of deburring is to derive the optimum conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.515-516
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• 2009

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1640-1651
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• 2009

In this paper we introduce a new approach to stroke based rendering using brush stroke profile. Our proposed method, based on image retrieval method, is a simple but flexible and scalable method to create various painting styles, for which scalable database constructed with the collection of real stroke data is used. Input image is reproduced with combinations of brush stoke in the database, when a search process to determinate appropriate brush stroke and a judgment process to decide whether to draw the retrieved brush stroke on the canvas or not are presented. In addition, this paper suggests a new brush stroke model and a depiction technique in order to utilize effective height information which allows natural texture depiction, or good visual effect, without carrying out physical simulation. Our method is able to create diverse variations of painting by controling various user parameters. It also provides scalable framework that can produce various painting styles with different artistic media by changing the stroke combinations of stroke database.