Scanning Probe Microscopy (SPM) refers to a versatile and powerful family of techniques used to observe and manipulate matter at the atomic and molecular scale. SPM involves the use of a physical probe, typically a sharp tip mounted on a cantilever, which scans the surface of a material to create detailed images or maps of its properties. This non-destructive technique provides researchers with valuable information about the surface topography, electrical, mechanical, and chemical properties of a sample.
The probe, being at the nanometer scale, interacts with the surface through a variety of forces, such as van der Waals, magnetic, or electrostatic forces. The interaction between the tip and the surface is meticulously controlled, allowing the resolution of SPM to reach sub-atomic levels.
There are several types of SPM techniques, each with its own specific capabilities. The most widely used variant is Atomic Force Microscopy (AFM), which employs a flexible cantilever equipped with a sharp tip to scan the surface. As the probe moves across the sample, it experiences changes in the deflection of the cantilever, which are subsequently converted into a three-dimensional image of the surface.
Other types of SPM include Scanning Tunneling Microscopy (STM), which relies on measuring the quantum tunneling current between the tip and the sample, and Kelvin Probe Force Microscopy (KPFM), which provides information about the surface potential and work function of a material.
SPM has found numerous applications in various scientific disciplines, such as materials science, nanotechnology, biology, and chemistry. It has greatly contributed to the understanding of fundamental phenomena at the nanoscale and has enabled the fabrication and characterization of nanoscale devices and structures.
