Scanning probe microscopy covers the methods where a sharp tip is scanned over a surface in a raster pattern and the interaction with the surface is recorded in each pixel to form an image of the interaction. There are a multitude of methods and interactions in SPM. Broadly speaking, there are three main categories:

• In scanning tunneling microscopy (STM), one uses an atomically sharp metallic tip and records the minute tunneling current between the tip and the surface, when the tip is hovering so close to the surface that electrons can move between the surface and the tip.
• In Atomic force microscopy (AFM), a cantilever with a sharp tip - somewhat like the needle of an old record player - is scanned over the surface and the topography or surface softness can be recorded.
• In Scanning near-field optical microscopy (SNOM) a probe with a smalle aperture is scanned over the surface collecting the light comming from regions much smaller than the wavelength of the light used.

• Upcoming page in this wiki book on AFM

• Atomic force microscope (AFM)
• Kelvin force microscopy
• Magnetic force microscope
• Scanning voltage microscopy
• Magnetic resonance force microscope
• Lateral force microscopy

• Upcoming page in this wiki book on STM
• Scanning tunneling microscopy (STM)

• Upcoming page in this wiki book on SNOM

Wiki links:

• Scanning Near-field optical microscopy (SNOM)
• Evanescent wave coupling

• A Practical Guide to Scanning Probe Microscopy by Rebecca Howland and Lisa Benatar
• homebrew atomic-resolution microscope

See also notes on editing this book about how to add references Nanotechnology/About#How to contribute.