Editing Microscope (section)

===Scanning probe===
{{main|Scanning probe microscopy}}

The different types of scanning probe microscopes arise from the many different types of interactions that occur when a small probe is scanned over and interacts with a specimen. These interactions or modes can be recorded or mapped as function of location on the surface to form a characterization map. The three most common types of scanning probe microscopes are [[atomic force microscopy|atomic force microscopes]] (AFM), [[near-field scanning optical microscopy|near-field scanning optical microscopes]] (NSOM or SNOM, scanning near-field optical microscopy), and [[scanning tunneling microscopy|scanning tunneling microscopes]] (STM).<ref name="Bhushan">{{cite book|editor1-last=Bhushan|editor1-first=Bharat|title=Springer handbook of nanotechnology|date=2010|publisher=Springer|location=Berlin|isbn=978-3-642-02525-9|page=620|edition=3rd rev. & extended}}</ref> An atomic force microscope has a fine probe, usually of silicon or silicon nitride, attached to a cantilever; the probe is scanned over the surface of the sample, and the forces that cause an interaction between the probe and the surface of the sample are measured and mapped. A near-field scanning optical microscope is similar to an AFM but its probe consists of a light source in an optical fiber covered with a tip that has usually an aperture for the light to pass through. The microscope can capture either transmitted or reflected light to measure very localized optical properties of the surface, commonly of a biological specimen. Scanning tunneling microscopes have a metal tip with a single apical atom; the tip is attached to a tube through which a current flows.<ref name="Sakurai">{{cite book|editor1-last=Sakurai|editor1-first=T.|editor2-last=Watanabe|editor2-first=Y.|title=Advances in scanning probe microscopy|date=2000|publisher=Springer|location=Berlin|isbn=978-3-642-56949-4}}</ref> The tip is scanned over the surface of a conductive sample until a tunneling current flows; the current is kept constant by computer movement of the tip and an image is formed by the recorded movements of the tip.<ref name="Bhushan"/>
[[File:Leaf epidermis.jpg|thumb|Leaf surface viewed by a scanning electron microscope]]