Acta Informatica Malaysia (AIM)

Atomic force microscopy works by mounting a probing tip on the free end of a micro mechanical cantilever and then scanning an item with that tip. Cantilever deflection occurs during horizontal scanning of the sample. Several ways exist for sensing the cantilever’s deflection. For example, this approach is commonly employed in optical beam deflection due to its simplicity. It compares the observed deflection to the set point deflection while scanning the sample stage. The next step is to reduce the error signal, which is the set point deflection minus the detected deflection, by advancing the sample stage in the Z-direction. This closed-loop feedback mechanism may sustain the cantilever deflection and, by extension, the force exerted by the contact between the tip and the sample, up to a certain point value. This causes the sample stage to move in three dimensions, which roughly follows the contours of the sample. As a result, the topographic picture is often generated from the Z-direction electrical impulses that drive the sample stage scanner. To create the AFM topographic picture, the authors in this study employed a weight function close to 3 to combine the height image, which is used to drive the Z-scanner, with the deflection image. By means of trial and error, the value of has been ascertained experimentally. A more accurate topographic picture is produced by this technique.