Design and Implementation of a Universal Probe Sensitivity Controller for Atomic Force Microscopes

• Main Authors: Sie, Shang-hong, 謝尚宏
• Other Authors: Wang, Yuan-Jay
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/15041927350047678584

碩士 === 東南科技大學 === 電機工程研究所 === 99 === The main purpose of this thesis is to design and implement a universal probe sensitivity controller for atomic force microscopes (AFM), which allows the AFMs to be applicable in air and liquid as well as in vacuum. To achieve this purpose, the electro-mechanical and optical subsystems of the homemade AFM are introduced. Then, the limitations of AFMs in liquid and vacuum are discussed. To improve the aforementioned phenomena, but using the positive feedback mechanism, the amplitude signal of the tip in the vertical direction is phase-shifted, amplified, and then summed up with the original driving signal of the tip to significantly enhance the resonant factor of the considered tip. In general, the higher the mentioned resonant factor, the better the probe sensitivity. Thus, the mentioned probe sensitivity controller could enhance the image quality the sample by adjusting the resonant factor and allows the AFMs to detect the topography of the sample in the conditions of air and liquid. To validate the effectiveness of the proposed probe sensitivity controller, the frequency response analyses are carried out. Further, the AFM is operated with and without probe sensitivity controller for comparison.