Loading...

An Investigation on the Resonant, Frequency and Nonlinear Behavior of Atomic Force Microscope (AFM) Modeled on the Basis of the Nonlocal Theory

khosravani, Ehsan | 2011

810 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 42471 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Ahmadian, Mohammad Taghi; Mehdigholi, Hamid
  7. Abstract:
  8. Atomic force microscope (AFM) has a significant capability of imaging surface topography on an atomic scale. It is also widely used for Nanolithography in MEMS/NEMS (micro/nanoelectromechanical systems). Although the conventional AFMs have a significant capability of nano-scale surface measurements, their probe tips cannot come in close proximity to the sidewalls, no matter how sharp they are. Therefore, no accurate nano-scale measurements at sidewalls and edges can be achieved by these conventional AFMs. In addition, regarding the increasing applications of micro-structures such as micro nozzles, micro gears, micro holes and micro trenches which all of them have sidewalls and edges, researchers proposed an assembled cantilever probe (ACP) for AFMs in order to determine the topography images and also the roughness and waviness of sidewalls and edges of these micro-structures. Unlike classical elasticity models, the nonlocal elasticity theory assumes that the stress at a point in a body depends not only on strains at that point, but also on strains at all other points of the body. New experiment results have explained the importance of the size effect in the mechanical properties of material when dimensions of the specimen become small. In this thesis the resonant, frequency and nonlinear behavior of atomic force microscope(AFM) modeled on the basis of the nonlocal theory is investigated. In order to achieve this goal, utilizing Hamilton principle, the governing partial differential equation (PDE) of the ACP motion and corresponding boundary conditions are obtained in the first step. In the next step, applying Galerkin and assuming mode method, the governing ordinary differential equation (ODE) of motion is derived. After that, using the perturbation techniques such as multiple scales and Lindsted-Poincare method, the governing nonlinear ODE of the system is solved analytically and the time and frequency responses are delineated in some figures. Furthermore, the influences of the system parameters such as the geometrical one on the frequency response of the system are assessed. In addition to the nonlinear vibration investigation, the torsional sensitivity and resonant frequency of the ACP are studied in this thesis and the effects of the geometrical parameters on them are investigated
  9. Keywords:
  10. Atomic Force Microscopy (AFM) ; Assembled Contilever Probe ; Sensitivity Analysis ; Perturbation Theory ; Nonlocal Theory ; Phase Plane

 Digital Object List

  • محتواي پايان نامه
  •   view

 Bookmark

No TOC