• Title/Summary/Keyword: nano-systems

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Extraction of Ballistic Parameters in 65 nm MOSFETs

  • Kim, Jun-Soo;Lee, Jae-Hong;Kwon, Yong-Min;Park, Byung-Gook;Lee, Jong-Duk;Shin, Hyung-Cheol
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.9 no.1
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    • pp.55-60
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    • 2009
  • The channel backscattering coefficient and injection velocity have been extracted experimentally in 65nm MOSFETs. Thanks to an experimental extraction methodology taking into account multi-subband population, we demonstrate that the short channel ballistic efficiency is slightly greater than long channel ballistic efficiency.

Artificial Vision Project by Micro-Bio Technologies

  • Kim Sung June;Jung Hum;Yu Young Suk;Yu Hyeong Gon;Cho Dong il;Lee Byeong Ho;Ku Yong Sook;Kim Eun Mi;Seo Jong Mo;Kim Hyo kyum;Kim Eui tae;Paik Seung June;Yoon Il Young
    • 한국가시화정보학회:학술대회논문집
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    • 2002.04a
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    • pp.51-78
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    • 2002
  • A number of research groups worldwide are studying electronic implants that can be mounted on retinal optic nerve/visual cortex to restore vision of patients suffering from retinal degeneration. The implants consist of a neural interface made of biocompatible materials, one or more integrated circuits for stimuli generation, a camera, an image processor, and a telemetric channel. The realization of these classes of neural prosthetic devices is largely due to the explosive development of micro- and nano-electronics technologies in the late $20^{th}$ century and biotechnologies more recently. Animal experiments showed promise and some human experiments are in progress to indicate that recognition of images can be obtained and improved over time. We, at NBS-ERC of SNU, have started our own retinal implant project in 2000. We have selected polyimide as the biomaterial for an epi-retinal stimulator. In-vitro and in-vivo biocompatibility studies have been performed on the electrode arrays. We have obtained good affinity to retinal pigment epithelial cells and no harmful effect. The implant also showed very good stability and safety in rabbit eye for 12 weeks. We have also demonstrated that through proper stimulation of inner retina, meaning vision can be obtained.

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Effect of SiO2 Layer of Si Substrate on the Growth of Multiwall-Carbon Nanotubes (실리콘 기판의 산화층이 다중벽 탄소나노튜브 성장에 미치는 영향)

  • Kim, Geum-Chae;Lee, Soo-Kyoung;Kim, Sang-Hyo;Hwang, Sook-Hyun;Choi, Hyon-Kwang;Jeon, Min-Hyon
    • Korean Journal of Materials Research
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    • v.19 no.1
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    • pp.50-53
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    • 2009
  • Multi-walled carbon nanotubes (MWNTs) were synthesized on different substrates (bare Si and $SiO_2$/Si substrate) to investigate dye-sensitized solar cell (DSSC) applications as counter electrode materials. The synthesis of MWNTs samples used identical conditions of a Fe catalyst created by thermal chemical vapor deposition at $900^{\circ}C$. It was found that the diameter of the MWNTs on the Si substrate sample is approximately $5{\sim}10nm$ larger than that of a $SiO_2$/Si substrate sample. Moreover, MWNTs on a Si substrate sample were well-crystallized in terms of their Raman spectrum. In addition, the MWNTs on Si substrate sample show an enhanced redox reaction, as observed through a smaller interface resistance and faster reaction rates in the EIS spectrum. The results show that DSSCs with a MWNT counter electrode on a bare Si substrate sample demonstrate energy conversion efficiency in excess of 1.4 %.

Effect of Electrochemical Properties and Optical Transmittance of Carbon Nanotubes Counter Electrodes on the Energy Conversion Efficiency of Dye-sensitized Solar Cells (염료감응형 태양전지의 탄소나노튜브 상대전극의 광투과도와 전기화학적 특성이 에너지 변환 효율에 미치는 영향)

  • Han, Young-Moon;Hwang, Sook-Hyun;Kang, Myung-Hoon;Kim, Young-Joo;Kim, Hyun-Kook;Kim, Sang-Hyo;Bae, Hyo-Jun;Choi, Hyon-Kwang;Jeon, Min-Hyon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.4
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    • pp.333-339
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    • 2011
  • In this work, electrochemical characteristics and optical transmittance of carbon nanotubes (CNTs) counter electrodes which had different amount of CNTs in CNTs slurries were analyzed. Two-step heat treatment processes were applied to achieve well-fabricated CNTs electrode. Three sets of CNTs electrodes and dye-sensitized solar cells (DSSCs) with CNTs counter electrodes were prepared. As the amount of CNTs increased, sheet resistance of CNTs electrode decreased. CNTs electrode with low sheet resistance had low electrochemical impedance and fast redox reaction. On the other hand, in case of CNTs counter electrode with low density of CNTs, performance of the dye-sensitized solar cell was improved due to its high optical transmittance. We found that the transmittance of CNTs counter electrode influence the performance of dye-sensitized solar cells.

Replication of High Density Patterned Media (고밀도 패턴드 미디어 성형에 관한 연구)

  • Lee, Nam-Seok;Choi, Yong;Kang, Shin-Ill
    • Transactions of the Society of Information Storage Systems
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    • v.1 no.2
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    • pp.192-196
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    • 2005
  • In this paper, we investigated the possibility of replicating patterned media by nano-injection molding process with a metallic nano-stamper. The original nano-master was fabricated by E-beam lithography and ICP etching process. The metallic nano-stamper was fabricated using a nanoimprint lithography and nano-electroforming process. The nano-patterned substrate was replicated using a nano-injection molding process without additional etching process. In nano-injection molding process, since the solidified layer, generated during the polymer filling, deteriorates transcribability of nano patterns by preventing the polymer melt from filling the nano cavities, an injection-mold system was constructed to actively control the stamper surface temperature using MEMS heater and sensors. The replicated polymeric patterns using nano-injection molding process were as small as 50 nm in diameter, 150 nm in pitch, and 50 nm in depth. The replicated polymeric patterns can be applied to high density patterned media.

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Development of Food-Grade Nano-Delivery Systems and Their Application to Dairy Foods: A Review (식품 소재를 이용한 나노전달체의 제조 및 유식품 적용에 관한 고찰)

  • Ha, Ho-Kyung;Lee, Won-Jae
    • Journal of Dairy Science and Biotechnology
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    • v.36 no.4
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    • pp.187-195
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    • 2018
  • Nano-delivery systems, such as nanoparticles, nanoemulsions, and nanoliposomes, are carriers that have been used to enhance the chemical as well as physical stability and bioavailability of bioactive compound. Food-grade nano-delivery system can be produced with edible biopolymers including proteins and carbohydrates. In addition to the low-toxicity, biocompatibility, and biodegradability of these biopolymers, their functional characteristics, such as their ability to bind hydrophobic bioactive compounds and form a gel, make them potential and ideal candidates for the fortification of bioactive compounds in functional dairy foods. This review focuses on different types of nano-delivery systems and edible biopolymers as delivery materials. In addition, the applications of food-grade nano-delivery systems to dairy foods are also described.