An atomic force microscope is an instrument that images the surface of a sample at extremely high resolution, down to the atomic or near-atomic scale, by dragging or tapping an extremely sharp probe, mounted on a flexible cantilever, across the surface and measuring the tiny deflections of the cantilever caused by the physical forces between the probe tip and the sample, rather than by using light or electrons as in optical or electron microscopy. The instrument was invented in 1985 and 1986 by Gerd Binnig, Calvin Quate and Christoph Gerber, building directly on the scanning tunneling microscope that Binnig had co-invented several years earlier, extending the same general scanning-probe approach to samples, including non-conducting materials, that the scanning tunneling microscope could not image. Atomic force microscopy has become an important tool across materials science, nanotechnology, chemistry and biology, valued for its ability to image and, in some applications, physically manipulate individual molecules and nanoscale structures under a wide range of conditions, including in liquid environments suitable for studying biological samples.
Facts
Invented YearSourced to the subject's own account MeasuresSourced to the subject's own accountForce between a probe tip and a sample surface, used to build topographic images and measure other local surface properties at sub-nanometer scale. 1 Operating PrincipleSourced to the subject's own accountA sharp tip is brought close to the sample surface; forces between the tip and surface deflect the cantilever holding the tip, and that deflection is what the instrument measures. 1 ResolutionSourced to the subject's own accountVertical distance resolution better than 0.1 nanometers, with forces of a few piconewtons routinely measurable. 1 Operating RangeSourced to the subject's own accountEffective interaction range roughly 1 to 10 nanometers above the surface, the span over which van der Waals forces dominate the tip-sample interaction. 1 Classification
Instrument ClassSourced to the subject's own account Connections
Invented By
Gerd Binnig, Scientists Binnig invented the atomic force microscope in 1986 with Calvin Quate and Christoph Gerber (neither a live entity in this atlas, so credited here to Binnig alone); Binnig had already shared the 1986 Nobel Prize in Physics for the earlier scanning tunneling microscope.
Used In
The atomic force microscope images and measures surface topography and mechanical properties at atomic-scale resolution, a core materials-science characterization tool.
Sources
1. Atomic Force Microscopy (Wikipedia)
WikipediaHistory section, opening sentence
The AFM was invented by IBM scientists in 1985.
Abilities and spatial resolution section
The AFM has three major abilities: force measurement, topographic imaging, and manipulation.
Probe section
the tip is brought very close to the surface of the object under investigation, and the cantilever is deflected by the interaction between the tip and the surface, which is what the AFM is designed to measure.
Force spectroscopy section
Forces of the order of a few piconewtons can now be routinely measured with a vertical distance resolution of better than 0.1 nanometers.
Non-contact mode section
The van der Waals forces, which are strongest from 1 nm to 10 nm above the surface, or any other long-range force that extends above the surface acts to decrease the resonance frequency of the cantilever.
Lede, instrument class
An atomic force microscope is an instrument that images the surface of a sample at extremely high resolution, down to the atomic or near-atomic scale, by dragging or tapping an extremely sharp probe, mounted on a flexible cantilever, across the surface and measuring the tiny deflections of the cantilever caused by the physical forces between the probe tip and the sample, rather than by using light or electrons as in optical or electron microscopy.
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