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Determination of the Surface Properties and Topography in AFM Using System Dynamics

Seifnejad Haghighi, Milad | 2019

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 51596 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Nejat, Hossein
  7. Abstract:
  8. Nowadays, the atomic force microscopy (AFM) has become a useful laboratory tool with variety of applications. In the traditional imaging technique, usually the amplitude or frequency of AFM tip oscillations is set at a desired value using a feedback control system which is a relatively slow process. In the current research, we propose an estimation approach which uses an adaptive fading extended Kalman filter (augmented with forgetting factor) as a system observer and couples with the system dynamics to determine the sample topography. As a result, in addition to state variables of system dynamic, the sample height as an unknown parameter is estimated with high accuracy in a relatively short period of time. Furthermore, by using the proposed approach, we show that the Hamaker constant can be estimated simultaneously. Simulation results demonstrate the efficiency of the proposed method not only in the elimination of the closed-loop control system but also in the simultaneous identification of sample height and Hamaker constant. Also, we apply AFEKF method to the both lumped parameter model and distributed one. Besides, by utilizing TDE control method, we control the tip position of the microcantilever to sense attractive and impulsive interaction force and consequently estimate the constants of attractive and impulsive term in interaction force equation
  9. Keywords:
  10. Atomic Force Microscopy (AFM) ; Surface Topography Study ; Adaptive Fading Kalman Filter ; Atomic Force Microscopy (AFM)Imaging ; Parameters Identification ; Systems Dynamics

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