STM+-+DW


 * STM - scanning tunnelling microscope**

a non-optical microscope that scans an electrical probe over a surface to be imaged to detect a weak electric current flowing between the tip and the surface. The STM (not to be confused with the scanning electron microscope) was invented by Russell Young and his colleagues at the National Bureau of Standards (now National Institute of Standards and Technology) in 1972. However, the STM developed by Young was susceptible to environmental disturbances (in particular to vibrations). In 1981, Gerd Binnig and Heinrich Rohrer of IBM's Zurich Lab in Switzerland were able to attenuate the vibrations and later showed mono-atomic, double-atomic and triple-atomic surface steps. Although initially greeted with some skepticism by materials scientists, the invention garnered Binnig and Rohrer a Nobel Prize in Physics (1986).




 * //Title//** //: Stadium Corral
 * Media** : Iron on Copper (111)//



//**Title** : Carbon Monoxide Man
 * Media** : Carbon Monoxide on Platinum (111)//

Here's how the images came to life...

 * 1) A tip is scanned over a surface at a distance of a few atomic diameters in a point-by-point and line-by-line fashion. At each point the tunneling current between the tip and the surface is measured. The tunneling current decreases exponentially with increasing distance and thus, through the use of a feedback loop, the vertical position of the tip can be adjusted to a constant distance from the surface.
 * 2) The amount of these adjustments is recorded and defines a grid of values which can be displayed as a grayscale image.
 * 3) Instead of assigning the values to a color we can also use them to deform the grid in the direction perpendicular to the surface.
 * 4) Now we can bring back the grayscale and paint each square according to an average of the four defining grid points.




 * 1) Now we paint the whole surface uniformly gray and switch on the lights.
 * 2) We can use several lights at different positions and with different colors.
 * 3) Instead of painting the surface just gray we can use a color palette and paint it according to height.
 * 4) Or we choose the color according to another surface property, let's say curvature.




 * SEM -** **scanning electron microscope** (**SEM**)

A type of electron microscope capable of producing high-resolution images of a sample surface. Due to the manner in which the image is created, SEM images have a characteristic three-dimensional appearance and are useful for judging the surface structure of the sample. The SEM was pioneered by Manfred von Ardenne in the 1930s. The instrument was further developed by Charles Oatley and first commercialized by Cambridge Instruments



Magnification: X 200

This is mosquito's head. The mosquito's head is mostly eye. The eyes of most insects are compound eyes, made up of many tiny lenses. Each lens sees a slightly different picture, making up a mosaic of the object it is looking at. This type of vision is very efficient at noticing very slight motions such as another insect trying to sneak up on it.



Magnification: X 500

The Black Widow is a cobweb spider. Their cobwebs are built in dark, out of the way places. The claw has three hooks, the middle one used to work the silk.

Scanning Electron Microscope is filming a STM (Movie)

( http://www.fz-juelich.de/video/emundts/film.mpg ) - Click and you can see the vidio of Scanning Electron Microscope is filming a STM