• Title, Summary, Keyword: AFM

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Modeling and Simulation of Nanorobotic Manipulation with an AFM probe

  • Kim, Deok-Ho;Park, Jungyul;Kim, Byungkyu;Kim, Kyunghwan
    • 제어로봇시스템학회:학술대회논문집
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    • pp.108.6-108
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    • 2002
  • It is greatly important to understand the mechanics of AFM-based nanorobotic manipulation for efficient and reliable handling of nanoparticles. Robust motion control of an AFM-based nanorobotic manipulation is much challenging due to uncertain mechanics in tip-sample interaction dominated by surface and intermolecular force and limitations in force and visual sensing capability to observe environment. This paper investigates a nanomechanic modeling which enables simulation for AFM-based nanorobotic manipulation , and its application to motion planning of an AFM-based nanorobot. Based on the modeling of intermolecular and adhesion force in AFM-based nanomanipulation, the behaviors of an AFM ca...

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Detection of Aflatoxin $M_1$ in Human and Porcine Urine and Its Risk Assessment (인축의 뇨 중 aflatoxin $M_1$의 오염분석 및 위해성 평가)

  • Kim, Hyun-Jung;Kwak, Bo-Yeon;Shon, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.41 no.2
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    • pp.215-219
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    • 2009
  • To conduct a risk assessment of $AFB_1$ intake, $AFM_1$, which is a metabolite of $AFB_1$ in the human and porcine urine, was determined by competitive direct ELISA (cdELISA). The detection limit of cdELISA using anti-$AFM_1$ antibody and $AFB_1$-HRP conjugate was 10 pg/mL. The recoveries of $AFM_1$ were 117-167% after the addition of $AFM_1$ in the human urine in a range of 3-100 pg/mL. 165 samples (95.5%) of those obtained from 172 persons evidenced measurable levels of urinary $AFM_1$. The detected $AFM_1$ ranges were 0-11.6 pg/mL and the average level of $AFM_1$ contamination was 2.74${\pm}$ 1.89 pg/mL. The estimated amount of $AFM_1$ excretion in the human urine was 3.97 ng/day and the estimated $AFB_1$ intake amount was 79.4 ng/day. The probable daily intake (PDI) of $AFB_1$ by the subjects was estimated to be 1.28 ng/kg bw/day, which was higher than the tolerable daily intake (TDI, 0.15 ng/kg bw/day). In the case of porcine urine, the $AFM_1$ ranged between 0.97-26.7 pg/mL and the average contaminated $AFM_1$ was 10.62${\pm}$4.39 pg/mL. The estimated amount of $AFM_1$ excretion in the porcine urine was 27.6 ng/day, and the estimated $AFB_1$ intake amount was 551 ng/day.

150 nm Pitch Measurement using Metrological AFM (길이 소급성을 갖는 AFM을 이용한 150nm 피치 측정)

  • ;I. Misumi;S. Gonda;T. Kurosawa
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.264-267
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    • 2003
  • Pitch measurements of 150 nm pitch one-dimensional grating standards were carried out using an contact mode atomic force microscopy(C-AFM) with a high resolution three-axis laser interferometer. It was called as 'Nano-metrological AFM' In Nano-metrological AFM, Three laser interferometers were aligned well to the end of AFM tip. Laser sources of the three-axis laser interferometer in the nano-metrological AFM were calibrated with an I$_2$-stablilzed He-Ne laser at a wavelength of 633 nm. So, the Abbe error was minimized and the result of the pitch measurement using the nano-metrological AFM has a traceability to the length standard directly. The uncertainty in the pitch measurement was estimated in accordance with the Guide to the Expression of Uncertainty in Measurement(GUM). The Primary source of uncertainty in the pitch-measurements was derived from repeatability of pitch-measurement, and its value was approx 0.186 nm. Expanded uncertainty(k=2) of less than 5.23 nm was obtained. It is suggested that the metrological AFM is a useful tool for the nano-metrological standard calibration.

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Anodization Process of the YBa2Cu3O7-x Strip Lines by the Conductive Atomic Force Microscope Tip (전도성 AFM 탐침에 의한 YBa2Cu3O7-x 스트립 라인의 산화피막 형성)

  • 고석철;강형곤;임성훈;한병성;이해성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.8
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    • pp.875-881
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    • 2004
  • Fundamental results obtained from an atomic force microscope (AFM) chemically-induced direct nano-lithography process are presented, which is regarded as a simple method for fabrication nm-scale devices such as superconducting flux flow transistors (SFFTs) and single electron tunneling transistors (SETs). Si cantilevers with Pt coating and with 30 nm thick TiO coating were used as conducting AFM tips in this study. We observed the surfaces of superconducting strip lines modified by AFM anodization' process. First, superconducting strip lines with scan size 2 ${\mu}{\textrm}{m}$${\times}$2 ${\mu}{\textrm}{m}$ have been anodized by AFM technology. The surface roughness was increased with the number of AFM scanning, The roughness variation was higher in case of the AFM tip with a positive voltage than with a negative voltage in respect of the strip surface. Second, we have patterned nm-scale oxide lines on ${YBa}-2{Cu}_3{O}_{7-x}$ superconducting microstrip surfaces by AFM conductive cantilever with a negative bias voltage. The ${YBa}-2{Cu}_3{O}_{7-x}$ oxide lines could be patterned by anodization technique. This research showed that the critical characteristics of superconducting thin films were be controlled by AFM anodization process technique. The AFM technique was expected to be used as a promising anodization technique for fabrication of an SFFT with nano-channel.

Non-contact type AFM using frequency separation scheme (주파수응답 분리방법을 이용한 비접촉식 AFM)

  • 이성규;염우섭;박기환;송기봉;김준호;김은경;박강호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.375-378
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    • 2002
  • In this paper, the frequency response separation scheme is proposed for high scanning speed and simple structure of non-contact type of AFM. A self-sensing cantilever is attached on the actuator for detect the atomic force between tip and the media surface. VCM or PZT are used for actuator. This paper presents the method to simplify the actuator structure and the performance of each actuator for non-contact type AFM. Based on the frequency response separation scheme, the only one actuator plays roles 1311owing low frequency surface and modulating self-sensing cantilever tip in contrast with convention non-contact type AFM. 10 ${\mu}{\textrm}{m}$ standard grid sample imaged to verify proposed scheme. This result shows the possibility simplifying the actuator structure and reducing cost of non-contact type AFM.

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Probing of Electrochemical Reactions for Battery Applications by Atomic Force Microscopy

  • Kim, Yun-Seok
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.98.2-98.2
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    • 2013
  • Electrochemical phenomena underpin a broad spectrum of energy, chemical, and information technologies such as resistive memories and secondary batteries. The optimization of functionalities in these devices requires understanding electrochemical mechanisms on the nanoscale. Even though the nanoscale electrochemical phenomena have been studied by electron microscopies, these methods are limited for analyzing dynamic electrochemical behavior and there is still lack of information on the nanoscale electrochemical mechanisms. The alternative way can be an atomic force microscopy (AFM) because AFM allows nanoscale measurements and, furthermore, electrochemical reaction can be controlled by an application of electric field through AFM tip. Here, I will summarize recent studies to probe nanoscale electrochemical reaction in battery applications by AFM. In particular, we have recently developed electromechanical based AFM techniques for exploring reversible and irreversible electrochemical phenomena on the nanoscale. The present work suggests new strategies to explore fundamental electrochemical mechanisms using the AFM approach and eventually will provide a powerful paradigm for probing spatially resolved electrochemical information for energy applications.

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Measurement of Deformations in Micro-Area Using High Resolution AFM Scanning Moiré Technique (고분해능 원자 현미경 스캐닝 무아레 기법을 이용한 미소 영역의 변형량 측정)

  • Park, Jin-Hyoung;Lee, Soon-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.6
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    • pp.659-664
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    • 2007
  • $Moire\'{e}$ interferometry is a useful technique to assess the reliability of electronic package because $Moire\'{e}$ interferometry can measure the whole-field and real-time deformations. The shear strain of a small crack site is important to the reliability assessment of electronic package. The optical limitation of $Moire\'{e}$ interferometry makes ambiguous the shear strain of a small area. An atomic force microscope (AFM) is used to measure the profile of a micro site. High resolution of AFM can apply to the $Moire\'{e}$ technique. AFM $Moire\'{e}$ technique is useful to measure the shear strain of a small area. In this research, the method to accurately measure the deformation of a small area by using AFM $Moire\'{e}$ is proposed. A phase-shifting method is applied to improve the resolution of AFM $Moire\'{e}$.

Research of Detection Method for Cytotoxic Effects of Environmental Pollutants Using Atomic Force Microscopy (AFM) in HeLa Cells (원자현미경(AFM)을 이용한 환경오염물질에 노출된 HeLa 세포의 표면변화 연구)

  • Lee, Si-Won;Lee, Soo-Il;Choi, Jin-Hee
    • Environmental Analysis Health and Toxicology
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    • v.23 no.1
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    • pp.47-51
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    • 2008
  • The toxicity of environmental pollutants was measured between a image of the surface topography in HeLa cells using atomic force microscopy for the possibility of toxic effect measurement and environmental monitoring. A image of the surface topography by AFM were estimated as toxic endpoints. The surface topography by AFM was observed a change of the cell surface in the environmental pollutants, but the standard of the measurement requires for the dose-effect degree. The overall results indicate that the possibility of measurement using AFM were confirmed a dose-effect degree related toxic effects, but it requres correlation between more various biomarker and AFM's measurements if the possibility of the toxic effect measurement was established.

An Enzyme-Linked Immunosorbent Assay for $Aflatoxin\;M_1$ in Cow's Milk without a Cleanup Procedure (희석에 의한 우유 중 $Aflatoxin\;M_1$의 효소면역측정법)

  • Shon, Dong-Hwa;Lim, Sun-Hee;Lee, Yin-Won
    • Korean Journal of Food Science and Technology
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    • v.28 no.6
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    • pp.1184-1187
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    • 1996
  • A simple and rapid detection system for $aflatoxin\;M_1\;(AFM_1)$ in cow's milk by an enzyme-linked immunosorbent assay (ELISA) was developed. Specific antibodies against $AFM_1$, conjugated to bovine serum albumin $(AFM_1-BSA)$ were raised in rabbits and purified. The cross-reactivities of the antibodies against aflatoxin analogs were less than 29.9%. When a competitive direct ELISA (cdELISA) for $AFM_1$, established by use of the antibodies was applied to the spike test of $AFM_1$ onto uncontaminated cow's milk, the assay recovery was unstable unless cow's milk was diluted to 40% (2:3) with phosphate buffered saline (PBS). In that condition of sample dilution, the mean ELISA recovery of $AFM_1$, from the cow's milk was 113% (coefficient of variation (CV) of each recovery percentage, 8.2%) in the range of $0.3{\sim}3.0\;ppb$. These results showed that the ELISA system could be a convenient tool to monitor the contamination of AFM1 more than 0.5 ppb in cow's milk (FDA allowance limit) easily.

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