How does Atomic Force Microscopy Work?
The working principle of AFM involves a
cantilever with a sharp tip that scans the surface of a sample. When the tip comes close to the surface,
interatomic forces between the tip and the sample cause deflections of the cantilever. These deflections are measured using a
laser beam reflected off the top surface of the cantilever into a photodetector.
What are the Modes of Operation in AFM?
There are several modes of operation in AFM, including
Contact Mode,
Tapping Mode, and
Non-Contact Mode. In Contact Mode, the tip is in constant contact with the surface, while in Tapping Mode, the cantilever oscillates near its resonance frequency, intermittently contacting the surface. Non-Contact Mode involves the tip hovering close to the surface without making direct contact.
What are the Limitations of AFM?
Despite its advantages, AFM has some limitations. The scanning speed is relatively slow compared to other imaging techniques, and the
scan size is limited to relatively small areas. Additionally, the sharpness and wear of the tip can affect the resolution and accuracy of the measurements.
Conclusion
Atomic Force Microscopy is an indispensable tool in the field of Nanotechnology, providing unparalleled insights into the nanoscale world. Its ability to image, measure, and manipulate materials at the atomic level makes it a cornerstone in nanoscience research and applications.
