History of Microscopes
Scanning Probe Microscopes
The scanning probe microscope (SPM) was developed in the 1980s to address the problem of the electron microscope - limited resolution in the vertical direction. Unlike an optical or electron microscope, an SPM does not consist of a light source or lenses. The SPM uses a pointed probe to scan a sample's surface, and this interaction allows the user to observe the surface condition. The scanning tunneling microscope (STM), which detects the tunneling current flowing between the probe and a sample, was developed by Gerd Binnig and Heinrich Rohrer at the IBM Zurich Research Laboratory. Several years later, the atomic force microscope (AFM), which detects the force acting between the probe and a sample, was developed at the same laboratory. The developments of these SPMs raised the resolution in the vertical direction to the nanometer range, enabling observation of surface irregularities at the atomic level.
In recent years, SPMs have continued to evolve with additional developments such as the magnetic force microscope (MSM), used to measure magnetic force, and the scanning near field optical microscope (SNOM) which is used to measure local optical characteristics.