31-07-2012, 10:57 AM
Nanotechnology and the Development of Computer Circuits
What is Nanotechnology?
Nanotechnology is the creation and use of materials or devices at extremely small scales.
Nanotechnology Foretold
Concept first introduced by American physicist Richard P. Feynman (1918-1988)
Calculated that an encyclopedia set could be compressed to fit the head of a pin.
Predicted several aspects in today’s nanotechnology
Advanced microscopes
Developments in fabrication methods
Possibilities of atom-to-atom assembly
Tools In Nanotechnology
The main tools used in nanotechnology are three main microscopes
Transmission Electron Microscope (TEM)
Atomic Force Microscope (AFM)
Scanning Tunneling Microscope (STM)
Transmission Electron Microscope (TEM)
Uses high-energy electron beam to probe material with thickness < 100 nm.
Some electrons are absorbed or bounced off object; some pass through the object and make magnified images
Digital camera records images.
Atomic Force Microscope (AFM)
Use small silicon tip as probe to make images of sample material
Probe moves along surface
Electrons of atoms in sample repel those in probe
Creates 3-D images
Scanning Tunneling Microscope (STM)
Uses nanosized probe to scan objects and materials
Uses tunneling to detect surface and creates a map of surface
Rate of electrons that tunnel from probe to surface related to distance between probe and surface
Other Uses for Tools
Microscopes used for imaging and manipulating nanostructures
“Arms” in AFMs and STMs used to move around individual atoms
Scientists at IBM made this image using an STM to with iron atoms into a circular structure.