• Title, Summary, Keyword: Atomic Force Microscope

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A STUDY ON SURFACE ROUGHNESS OF COMPOSITE RESINS AFTER FINISHING AND POLISHING -an Atomic Force Microscope study (연마방법에 따른 복합레진의 활택도에 관한 연군 -Atomic Force Microscope를 이용한 연구)

  • Kim, Hyeong-Seob;Woo, Yi-Hyung
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.4
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    • pp.719-741
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    • 1997
  • This study was undertaken to compare by Atomic Force Microscope the effects of various finishing and polishing instruments on surface roughness of filling and veneering composite resins. Seven composite resins were studied : Silux Plus (3M Dental Products, U.S.A.), Charisma (Heraeus Kulzer, Germany), Prisma THP (L.D.Caulk, Dentsply, U.S.A.), Photoclearfil (Kuraray, Japan), Cesead (Kuraray, Japan), Thermoresin LC (GC, Japan), Artglass (Heraeus Kulzer, Germany). Samples were placed and polymerized in holes (2mm thick and 8.5mm in diameter) machined in Teflon mold under glass plate, ensuring excess of material and moulded to shape with polyester matrix strip. Except control group (Polyester matrix strip), all experimental groups were finished and polishied under manufacturer's instructions. The finishing and polishing procedure were : carbide bur (E.T carbide set 4159, Komet, Germany), diamond bur (composite resin polishing bur set, GC, Japan), aluminum-oxide disc (Sof-Lex Pop-On, 3M Dental Products, U.S.A.), diamond-particle disc (Dia-Finish, Renfert Germany), white stone bur & rubber point( composite finishing kit, EDENTA, Swiss), respectively. Each specimens were evaluated for the surface roughness with Atomic Force Microscope (AutoProbe CP, Park Scientific Instruments, U.S.A.) under contact mode and constant height mode. The results as follows : 1. Except Thermoresin LC, all experimental composite resin groups showed more rougher than control group after finishing and polishing(p<0.1). 2. A surface as smooth as control group was obtained by $Al_{2}O_{3}$ disc all filling composite resin groups except Charisma and all veneering composite resin groups except Thermoresin LC(p<0.05). 3. In case of Thermoresin LC, there were no statistically significant differences before and after finishing and polishing(p>0.1). 4. Carbide bur, diamond bur showed rough surfaces in all composite resin groups, so these were inappropriate for the final polishing instruments.

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Sensing System for Measuring Deflection of Microcantilever (마이크로 캔틸레버 굽힘 측정을 위한 센싱시스템)

  • Kim, Hyun-Chul;Lee, Sang-Heon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.9
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    • pp.961-964
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    • 2012
  • This paper presents a sensing system to measure the deflection of a microcantilever in an atomic force microscope. In general, the optical lever method and interferometry are used for the sensing system; however, their size and cost leaves considerable room for improvement. Therefore, we used an optical pickup head whose operating principle is based on the astigmatism of the commercial optical disk drives. The developed sensing system was applied to a laboratory atomic force microscope, and satisfactory results were obtained.

Relationships between Carrier Lifetime and Surface Roughness in Silicon Wafer by Mechanical Damage (기계적 손상에 의한 실리콘 웨이퍼의 반송자 수명과 표면 거칠기와의 관계)

  • 최치영;조상희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.12 no.1
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    • pp.27-34
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    • 1999
  • We investigated the effect of mechanical back side damage in viewpoint of electrical and surface morphological characteristics in Czochralski silicon wafer. The intensity of mechanical damage was evaluated by minority carrier recombination lifetime by laser excitation/microwave reflection photoconductance decay technique, atomic force microscope, optical microscope, wet oxidation/preferential etching methods. The data indicate that the higher the mechanical damage degree, the lower the minority carrier lifetime, and surface roughness, damage depth and density of oxidation induced stacking fault increased proportionally.

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Multi-Functional Probe Recording: Field-Induced Recording and Near-Field Optical Readout

  • Park, Kang-Ho;Kim, Jeong-Yong;Song, Ki-Bong;Lee, Sung-Q;Kim, Jun-Ho;Kim, Eun-Kyoung
    • ETRI Journal
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    • v.26 no.3
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    • pp.189-194
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    • 2004
  • We demonstrate a high-speed recording based on field-induced manipulation in combination with an optical reading of recorded bits on Au cluster films using the atomic force microscope (AFM) and the near-field scanning optical microscope (NSOM). We reproduced 50 nm-sized mounds by applying short electrical pulses to conducting tips in a non-contact mode as a writing process. The recorded marks were then optically read using bent fiber probes in a transmission mode. A strong enhancement of light transmission is attributed to the local surface plasmon excitation on the protruded dots.

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A study of the design and control system for the ultra-precision stage (초정밀 스테이지 설계 및 제어 시스템에 관한 연구)

  • Park Jongsung;Jeong Kyuwon
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • pp.54-59
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    • 2005
  • Recently, the ultra-precision stage is widely used in the fields of the nano-technology, specially in AFMs(Atomic Force Microscope) and STMs(Scanning Tunneling Microscope). In this paper, the ultra-precision stage which consists of flexure hinges, piezoelectric actuator, and ultra-precision linear encoder, is designed and developed. The guide mechanism which consisted of flexure hinges is analyzed by Finite Element Method. And we derived the transfer function of the system in 1st order system from step responses according to the magnitude. We performed simulation for the model to tune the control gain and applied the gains to the developed system. Experimental results found that the stage can be controlled in 5 nm resolution by PID controller.

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Friction and Pull-off Forces on Submicron-Size Asperity Measured in High Vacuum

  • Ando, Y.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.57-58
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    • 2002
  • Asperity arrays and Independent asperities were fabricated on a silicon plate. Then pull-off and friction forces were measured on each asperity pattern by using AFM (atomic force microscope) in humid air and high vacuum of $2{\times}10^{-5}$ Pa. The probe of AFM cantilever has a flat square of about $1\;{\mu}m^2$ on its tip. The results showed that the pull-off force was proportional to the curvature radius of asperity peak in each ambient condition. The friction force was proportional to the pull-off force and was slightly higher in the humid air than in the high vacuum.

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Adaptive Control of the Atomic Force Microscope of Tapping Mode: Chaotic Behavior Analysis (진동방식의 원자간력 현미경으로 표면형상 측정시 발행하는 혼돈현상의 적응제어)

  • Kang, Dong-Hunn;Hong, Keum-Shik
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.1
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    • pp.57-65
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    • 2000
  • In this paper, a model reference adaptive control for the atomic force microscope (AFM) of tapping mode is investigated. The dynamics between the AFM system and al sample is mathematically modeled as a second order spring-mass-damper system with oscillatory inputs. The attractive and repulsive forces between the tip of the AFM system and the sample are derived using the Lennard-Jones potential energy. By non-dimensionalizing the displacement of the tip and the input frequency, the chaotic behavior near a resonance frequency is better depicted through the non-dimensionalized equations. Four nonlinear analysis techniques, a phase portrait, sensitive dependence on initial conditions, a power spectral density function, and a Pomcare map are investigated. Because the equations of motion derived in this paper involve unknown parameter values such as the damping effect of the air and the interaction constants between materials, the standard model reference adaptive control is adopted. Two control objectives, the prevention of chaos and the tracking of reference signal, are pursued. Simulation results are included.

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Anodic Oxidation Lithography via Atomic Force Microscope on Organic Resist Layers (유기 저항막을 이용한 원자힘 현미경 양극산화 패터닝 기술)

  • Kim, Sung-Kyoung;Lee, Hai-Won
    • Polymer Korea
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    • v.30 no.3
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    • pp.187-195
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    • 2006
  • Atomic force microscope (AFM)-based anodic oxidation lithography has gained great in forests in fabricating nanometer scale features on semiconductor or metal substrates beyond the limitation of optical lithography. In this article AFM anodic oxidation lithography and its organic resist layers are introduced based on our previous works. Organic resist layers of self-assembled monolayers, Langmuir-Blodgett films and polymer films aye suggested to play a key role in enhancing the aspect ratio of producing features, the lithographic speed, and spatial precision in AFM anodic oxidation lithography.