Scanning Probe Microscopy (SPM) - Principles and Modes of Operation

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It is essential to have the tools that enable the maker to see, control, and engineer at the atomic level, before making anything. Scanning probe microscopy (SPM) is one such tool that can be employed for this purpose.

Activities for handling atom and molecules at the nanoscale level are controlled by the use of scanning probe microscopes in ultra-high vacuum. SPM is a method that is used to examine the properties of surfaces at the atomic level.

In contrast to conventional microscopy, which employs light waves for imaging, SPM includes scanning the sample surface with a very fine probe (tip), and tracking the strength of the interaction between the surface and tip.

How Scanning Probe Microscopy Works

SPM scans an atomically sharp probe over a surface, usually at a distance of a few nanometers or angstroms. The contact between the sharp probe and surface produces a 3D topographic image of the surface at the atomic scale.

In contrast to other instruments that open a window to the realm of molecule-sized spaces, SPMs are comparatively simple, inexpensive, and user-friendly. A particularly appealing feature about the proximal probes is their multipurpose capacity that provides not only a view of separate atoms but also ways to pick them up, shift them around, and place them at will.

Modes of Scanning Probe Microscopy

The most common modes in SPM are atomic force microscopy (AFM) and scanning tunneling microscopy (STM).