• Title/Summary/Keyword: AFM

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Regiospecific Orientation of Single-chain Antibody and Atomic Force Microscope (AFM) Images

  • Kyusik Yun;Park, Seonhee;Hyeonbong Pyo;Kim, Seunghwan;Lee, Sooyeul
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.4 no.1
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    • pp.72-77
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    • 1999
  • An antibody containing a genetically engineered lipid group at the N-termunus and a hexahistidinyl tag at the C-terminus (Lpp-scF-His6) was immobilized in an oriented manner on the surface of liposome. Liposomes, consisting of antibody and phosphatidyl-choline, have been prepared and imaged by AFM. For AFM visualization, the resulting liposomes were bound on the surface of mica by two different mechanisms. The histidine tags present in the antibody molecules of the immonuliposome were anchored to the NiCl2 treated mica surface. Alternatively, the immunoliposomes were immunochemically bound on antigen-coated mica surface. Both approaches yielded liposomes which were clearly imaged without damage by AFM in ambient condition.

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Quantitative Measurement of Nano-scale Force using Atomic Force Microscopy (AFM을 이용한 나노스케일 힘의 정량적 측정)

  • Chung, Koo-Hyun
    • Tribology and Lubricants
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    • v.28 no.2
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    • pp.62-69
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    • 2012
  • Atomic force microscopy (AFM) has been widely utilized as a versatile tool not only for imaging surfaces but also for understanding nano-scale interfacial phenomena. By measuring the responses of the photo detector due to bending and torsion of the cantilever, which are caused by the interactions between the probe and the sample surface, various interfacial phenomena and properties can be explored. One of the challenges faced by AFM researchers originates in the physics of measuring the small forces that act between the probe of a force sensing cantilever and the sample. To understand the interactions between the probe and the sample quantitatively, the force calibration is essential. In this work, the procedures used to calibrate AFM instrumentation for nano-scale force measurement in normal and lateral directions are reviewed.

Fabrication of silicon nano-ribbon and nano-FETs by using AFM anodic oxidation

  • Hwang, Min-Yeong;Choe, Chang-Yong;Jeong, Ji-Cheol;An, Jeong-Jun;Gu, Sang-Mo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.54-54
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    • 2009
  • AFM anodic oxidation has the capability of patterning complex nano-patterns under relatively high speeds and low voltage. We report the fabrication using a atomic force microscopy (AFM) of silicon nano-ribbon and nano-field effect transistors (FETs). The fabricated nano-patterns have great potential characteristics in various fields due to their interesting electronic, optical and other profiles. The results shows that oxide width and the separation between the oxide patterns can be optimally controlled. The subsequently fabricated silicon nano-ribbon and nano-FET working devices were controled by various tip-sample bias-voltages and scan speed of AFM anodic oxidation. The results may be applied for highly integration circuits and sensitive optical sensor applications.

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The Effects of Surface Energy and Roughness on Adhesion Force (표면에너지와 거칠기가 응착력에 미치는 영향)

  • Rha, Jong-Joo;Kwon, Sik-Cheol;Jeong, Yong-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.11 s.254
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    • pp.1335-1347
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    • 2006
  • Surface energies calculated from measured contact angles between several solutions and test samples, such as Si wafer, $Al_2O_3$, $SiO_2$, PTFE(Polytertrafluoroethylene), and DLC(Diamond Like Carbon) films, based on geometric mean method and Lewis acid base method. In order to relate roughness to adhesion force, surface roughness of test samples were scanned large area and small by AFM(Atomic Force Microscopy). Roughness was representative of test samples in large scan area and comparable with AFM tip radius in small scan area. Adhesion forces between AFM tip and test samples were matched well with order of roughness rather then surface energy. When AFM tips having different radius were used to measure adhesion force on DLCI film, sharper AFM tip was, smaller adhesion force was measured. Therefore contact area was more important factor to determine adhesion force.

An Experiment about Assembling Condition of Carbon Nanotube Tip for AFM (주사탐침현미경용 카본나노튜브 팁의 조립 조건 실험)

  • 박준기;한창수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.501-504
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    • 2004
  • This paper describes the fabrication method for atomic force microscopy(AFM) tip with multi-walled carbon nanotube(MWNT). For making a carbon nanotube (CNT) modified tips, AC electric field which cause the dielectrophoresis was used for alignment and deposition of CNTs in this research. By dropping the MWNT solution and applying an electric field between an AFM tip and an electrode, MWNTs which were dispersed into a diluted solution were directly assembled onto the apex of the AFM tips due to the attraction by the dielectrophoretic force. In this case, we investigate the effect of the angle between a tip axis and an electrode. Experimental setup were presented, and then CNT attached AFM tips are successfully shown in this paper.

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Nonlinear Modeling of Dynamic AFM Using Proper Orthogonal Modes (적합직교모드를 이용한 동적모드 AFM 의 비선형 모델링)

  • Hong, Sang-Hyuk;Lee, Soo-Il
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.379-382
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    • 2007
  • The proper orthogonal decomposition(POD) is used to the modal analysis of microcantilever of dynamic mode atomic force microscopy(AFM). The proper orthogonal modes(POM) are extracted from vibrating signals of microcantilever when it resonates and taps the sample. The POMs resemble the linear normal modes(LNM) of cantilever vibrating at each resonance frequency. Some of POMs in tapping microcantilever show quite different shapes from the POMs of the resonating microcantilever. Also this POMs can be applied to model for the complex nonlinear behavior of the dynamic mode AFM microcantilevers.

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Proper Orthogonal Mode Extraction of AFM Microcantilevers in Dynamic Mode (동적모드 AFM 마이크로캔틸레버의 적합직교모드 추출)

  • Cho, Hong-Mo;Hong, Sang-Hyuk;Kwon, Won-Tae;Lee, Soo-Il
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.264-268
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    • 2007
  • Proper orthogonal decomposition(POD) is a method for extracting bases for modal decomposition from the ensemble of signals. We verified the connection of the proper orthogonal modes(POMs) and the linear normal modes(LNMs) through MATLAB simulation for the simple cantilever and AFM microcantilever models. Using the POMs, we can analyze and model effectively the dynamic mode of AFM microcantievers.

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