• Title/Summary/Keyword: Lab-on-a-Chip

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Fracture Strength of All-Ceramic 3-Unit Fixed Partial Dentures Manufactured by CAD/CAM and Copy-Milling Systems (CAD/CAM 및 카피밀링 시스템을 이용하여 제작한 구치부 3-유닛 고정성 국소의치의 파절강도)

  • Kang, Hoo-Won;Kim, Hee-Jin;Kim, Jang-Ju;Ko, Myung-Won
    • Journal of Technologic Dentistry
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    • v.34 no.2
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    • pp.95-103
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    • 2012
  • Purpose: Fracture strength of all-ceramic 3-unit fixed partial dentures manufactured by CAD/CAM and copy-milling systems were evaluated. Methods: Zirconia cores were made by milling the pre-sintered zirconia block by CAD/CAM or copy milling method followed by subsequent sintering. By building-up the corresponding porcelains on the core, all-ceramic bridges were fabricated, and those were evaluated in comparison with PFM fixed partial denture. Results: During the flexural test of the 3-unit PFM bridge, the porcelain started to chip or break at 507.28(${\pm}62.82$)kgf and the metal framework did not break until the maximum load level of 800kgf which was set in the testing instrument of this study. However, among all-ceramic restoration test groups, Everest(EV) group showed a peeling off or breakage of the porcelain from 365.64(${\pm}64.96$)kgf and the core was broken at 491.77(${\pm}55.62$)kgf. Those values of Zirkonzahn(ZR) were 431.03(${\pm}58.47$)kgf and 602.74(${\pm}48.44$)kgf, respectively. The break strength of the porcelain of PFM(PM) group was significantly higher than that of EV (p<0.05) group and there was no significant difference when comparing to that of ZR (p>0.05). ZR group showed higher break strength than that of EV group however there was no significant difference (p>0.05). The break strength of cores were in the increasing order of EV < ZR < PM (p<0.05). Conclusion: We could find that even though the PM group fractured at much higher value than all-ceramic cores, the breakage values of the porcelain of PM group with crack formation or delamination, which will be regarded as clinical failure, was significantly higher than that of EV group and not significantly higher than that of ZR group at p-values of 0.05. The break strength of ZR group was higher than that of EV group at an insignificant level(p>0.05).

The Mechanism and Detection of Tool Fracture using Sensor Fusion in Cutting Force and AE Signals for Small Diameter Ball-end Milling (미세 볼엔드밀가공시 절삭력과 음향방출신호에 의한 공구 파손 검출 및 메커니즘)

  • Wang, Duck-Hyun;Kim, Won-Il;Lim, Jeong-Suk
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.3
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    • pp.24-31
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    • 2004
  • A successful on-line monitoring system for conventional machining operations has the potential to reduce cost, guarantee consistency of product quality, improve productivity and provide a safer environment for the operator. In fine-shape machining, typical signs of tool problems such as vibration, noise, chip flow characteristics and visual signs are almost unnoticeable without the use of special equipment. These characteristics increase the importance of automatic monitoring in fine-shape machining, however, sensing and interpretation of signals ar more complex. In addition, the shafts of the mini-tools break before the typical extensive cutting edge of the tool gets damaged. In this study, the existence of a relationship between the characteristics of the cutting force and tool usage was investigated, and tool breakage detection algorithm by LabVIEW was developed and the following results are obtained. It was possible to use a relative error compare which mainly used in established experiment and investigated tool breakage detection algorithm in time domain which can detect AE and cutting force signals more effective and accurate.

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Development of W-band Transceiver Module using Manufactured MMIC (국내개발 MMIC칩을 적용한 W-Band 송수신모듈 개발)

  • Kim, Wan-Sik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.2
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    • pp.233-237
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    • 2017
  • The dual-channel receiver MMIC which is composed of LNA, Mixer, LO-amp and temperature compensation circuit is designed on a single chip. For the performance comparison, a FMCW radar transceiver module using commercial MMICs is also implemented. As a result, Multi-channel Transceiver using manufactured MMIC shows an improved performance such as noise figure and gain flatness compare to purchased MMIC.

Novel Fabrication of Designed Silica Structures Inspired by Silicatein-a

  • Park, Ji-Hun;Kwon, Sun-Bum;Lee, Hee-Seung;Choi, In-Sung S.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.557-557
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    • 2012
  • Silicatein-${\alpha}$, the enzyme extracted from silica spicules in glass sponges, has been studied extensively in the way of chemistry from 1999, in which the pioneering work by Morse, D. E. - the discovery of the enzymatic hydrolysis in Silicatein-${\alpha}$ - was published. Since its reaction conditions are physiologically favored, synthesis of various materials, such as gallium oxide, zirconium oxide, and silicon oxide, was achieved without any hazardous wastes. Although some groups synthesized oxide films and particles, they have not achieved yet controlled morphogenesis in the reaction conditions mentioned above. With the knowledge of catalytic triad involved in hydrolysis of silicone alkoxide and oligomerization of silicic acid, we designed the novel peptide amphiphiles to not only form self-assembled structure, but also display similar activities to silicatein-${\alpha}$. Designed templates were able to self-assemble into left-handed helices for the peptide amphiphiles with L-form amino acid, catalyzing polycondensation of silicic acids onto the surface of them. It led to the formation of silica helices with 30-50 nm diameters. These results were characterized by various techniques, including SEM, TEM, and STEM. Given the situation that nano-bio-technology, the bio-applicable technology in nanometer scale, has been attracting considerable attention; this result could be applied to the latest applications in biotechnology, such as biosensors, lab-on-a-chip, biocompatible nanodevices.

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A DC Reference Fluctuation Reduction Circuit for High-Speed CMOS A/D Converter (고속 CMOS A/D 변환기를 위한 기준전압 흔들림 감쇄 회로)

  • Park Sang-Kyu;Hwang Sang-Hoon;Song Min-Kyu
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.6 s.348
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    • pp.53-61
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    • 2006
  • In high speed flash type or pipelining type A/D Converter, the faster sampling frequency is, the more the effect of DC reference fluctuation is increased by clock feed-through and kick-back. When we measure A/D Converter, further, external noise increases reference voltage fluctuation. Thus reference fluctuation reduction circuit must be needed in high speed A/D converter. Conventional circuit simply uses capacitor but layout area is large and it's not efficient. In this paper, a reference fluctuation reduction circuit using transmission gate is proposed. In order to verify the proposed technique, we designed and manufactured 6bit 2GSPS CMOS A/D converter. The A/D converter is based on 0.18um 1-poly 5-metal N-well CMOS technology, and it consumes 145mW at 1.8V power supply. It occupies chip area of $977um\times1040um$. Experimental result shows that SNDR is 36.25 dB and INL/DNL ${\pm}0.5LSB$ when sampling frequency is 2GHz.

TEST DB: The intelligent data management system for Toxicogenomics (독성유전체학 연구를 위한 지능적 데이터 관리 시스템)

  • Lee, Wan-Seon;Jeon, Ki-Seon;Um, Chan-Hwi;Hwang, Seung-Young;Jung, Jin-Wook;Kim, Seung-Jun;Kang, Kyung-Sun;Park, Joon-Suk;Hwang, Jae-Woong;Kang, Jong-Soo;Lee, Gyoung-Jae;Chon, Kum-Jin;Kim, Yang-Suk
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2003.10a
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    • pp.66-72
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    • 2003
  • Toxicogenomics is now emerging as one of the most important genomics application because the toxicity test based on gene expression profiles is expected more precise and efficient than current histopathological approach in pre-clinical phase. One of the challenging points in Toxicogenomics is the construction of intelligent database management system which can deal with very heterogeneous and complex data from many different experimental and information sources. Here we present a new Toxicogenomics database developed as a part of 'Toxicogenomics for Efficient Safety Test (TEST) project'. The TEST database is especially focused on the connectivity of heterogeneous data and intelligent query system which enables users to get inspiration from the complex data sets. The database deals with four kinds of information; compound information, histopathological information, gene expression information, and annotation information. Currently, TEST database has Toxicogenomics information fer 12 molecules with 4 efficacy classes; anti cancer, antibiotic, hypotension, and gastric ulcer. Users can easily access all kinds of detailed information about there compounds and simultaneously, users can also check the confidence of retrieved information by browsing the quality of experimental data and toxicity grade of gene generated from our toxicology annotation system. Intelligent query system is designed for multiple comparisons of experimental data because the comparison of experimental data according to histopathological toxicity, compounds, efficacy, and individual variation is crucial to find common genetic characteristics .Our presented system can be a good information source for the study of toxicology mechanism in the genome-wide level and also can be utilized fur the design of toxicity test chip.

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Design of an 1.8V 6-bit 2GSPS CMOS ADC with an One-Zero Detecting Encoder and Buffered Reference (One-Zero 감지기와 버퍼드 기준 저항열을 가진 1.8V 6-bit 2GSPS CMOS ADC 설계)

  • Park Yu Jin;Hwang Sang Hoon;Song Min Kyu
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.6 s.336
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    • pp.1-8
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    • 2005
  • In this paper, CMOS A/D converter with 6bit 2GSPS Nyquist input at 1.8V is designed. In order to obtain the resolution of 6bit and the character of high-speed operation, we present an Interpolation type architecture. In order to overcome the problems of high speed operation, a novel One-zero Detecting Encoder, a circuit to reduce the Reference Fluctuation, an Averaging Resistor and a Track & Hold, a novel Buffered Reference for the improved SNR are proposed. The proposed ADC is based on 0.18um 1-poly 3-metal N-well CMOS technology, and it consumes 145mW at 1.8V power supply and occupies chip area of 977um $\times$ 1040um. Experimental result show that SNDR is 36.25 dB when sampling frequency is 2GHz and INL/DNL is $\pm$0.5LSB at static performance.

Fabrication of the temperature controllable microreactor for trypsin treatment (온도 조절이 가능한 트립신 전처리 반응침의 제작)

  • Sim, Tae-Seok;Lee, Kook-Nyung;Joo, Hwang-Soo;Kim, Dae-Weon;Kim, Byung-Gee;Kim, Yong-Hyup;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2003.10a
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    • pp.45-48
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    • 2003
  • In the research of proteomics, mass spectrometry analysis is the essential method for identification of the unknown proteins. Trypsin treatment for the sample preparation of mass spectrometry is the inevitable procedure[1]. However, sample preparation procedure is cumbersome and time consuming. To resolve these problems, Temperature controllable microreactor was designed and fabricated. It consists of metering chamber, micro channel, reaction chamber, platinum (Pt) thin film heater and a temperature sensor so that micro metering and mixture of reagent with temperature control can be done on the same chip. The total size of the fabricated microreactor was $37{\times}30{\times}1\;mm^3$ and the size of channel cross section was $200{\times}100{\mu}m^2$. PID temperature controller was realized using NI DAQ, PCI-MIO-l6E-1 board and LabVIEW program.

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수질 모니터링을 위한 암모니아 분석 칩과 중금속 센서

  • Park, Jun-Sik;Hwang, Gil-Ho;Gang, Seong-Gun
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.18.2-18.2
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    • 2011
  • 생활수준이 향상되고, 환경오염이 가속되면서 환경에 대한 관심이 더욱 증대되고 있다. 수질센서의 경우, 그 측정 항목이 매우 다양하고, 높은 정밀도를 요하고 있을 뿐만 아니라 지속적인 실시간 모니터링을 요구하고 있어, 기술적으로 해결해야 할 문제가 많이 남아 있다. 또한, 현재 약 15% 정도로 매우 낮은 국산화율을 보이고 있어, 대부분의 주요 센서들이 수입에 의존하고 있는 실정이다. 수질을 측정하기 위한 센서는 크게 두 가지 형태로 나누어 질 수 있는데, 하나는 flow injection analysis (FIA) 방식이며, 다른 하나는 Probe 방식의 센서이다. 본 발표에서는 수질 센서에 대한 최근 국내 기술 동향과, 수질 모니터링을 위한 Lab-on-a-chip 형 암모니아 분석 칩, Probe 형 중금속 센서 연구 개발 결과를 요약하고자 한다. 암모니아 분석 칩은 마이크로 유체 소자 내에서 Berthelot reaction을 유도하고, 흡광법에 의하여 물 속에 존재하는 암모니아를 간접적으로 측정하는 방법이다. 또한, 중금속 센서로 일반적인 working electrode 소재로 사용되는 독성이 있는 Hg 보다 친환경적인 개발된 bismuth-modified carbon nanotube와 같은 Bi계 복합소재를 적용하여 물 속에 존재하는 저 농도의 Pb, Cd, Zn을 측정 분석할 수 있었다. 본 연구를 통해 개발된 분석칩과 중금속 센서를 이용하여 하천에서 샘플링된 물에서의 암모니아 및 중금속 농도를 각각 분석할 수 있었다.

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Design and fabrication of molds moved wall thickness for biochip considering molding stability (성형안정성을 고려한 바이오칩용 측벽 이동형 금형설계 및 제작)

  • Go, Young-Bae;Kim, Jong-Sun;Min, In-Gi;Yu, Jae-Won;Kim, Jong-Duck;Yoon, Kyung-Hwan;Lee, Sung-Ho;Kim, Kyung-Min;Kim, Byung-Il;Hwang, Chul-Jin
    • Design & Manufacturing
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    • v.2 no.2
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    • pp.25-28
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    • 2008
  • Micro fabrication of biochip such like lab-on-a-chip becomes increasingly important. In this study, we designed and manufactured of new molds which were main factors for forming process in order to mass produce of biochip using forming process. Forming analysis of biochip was performed by Moldflow software. Results of this study are able to design and manufacture the mold which can be easy to eject the workpiece by using the slide mechanism for biochip.

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