are extremely strong
, and cool
. The hexagonal patterns of carbon
gives each carbon atom 3 other carbons to bond with. Because Carbon has 4 electrons
in its valence shell
, exactly one of the bonds that any carbon has would be a double bond
. However, which bond is double is not constant, in fact, electrons can move about freely in this type of substance (eg. things like graphite
) and therefore they act similar to metals and are good conducters of electricity. The reason they are very strong is because they are symmetrical hollow cylinders of a stable substance. If you know anything about tension
, you know why hollow cylinders can withstand so much bending; I'm sure this is explained in some physics
So, carbon nanotubes are long, electrically conductive, and strong, but what does this have to do with tweezers?
Take a tiny piece of elongated glass (made by heating glass up and stretching it repeatedly and then cutting it until you have a microscopic piece of glass thread) with an electrode on either side, and then attach two long carbon nanotubes to either electrode. I am not sure how the tubes are connected but a guess is that one would use evaporated gold to coat the surface of the glass and the nanotube, binding them together (If anybody actually knows how exactly the tubes are connected, please tell me). Now you have something like the diagram. The glass is the base of the tweezers and the nanotubes are the prongs.
Now you have the structure of the tweezers. To operate them, simply hook the electrodes up to a voltage source, and get a different charge on each of the electrodes. This makes nanotube A and nanotube B have different charges, so they will be attracted to each other, and thus they will pivot on the glass and the far ends will move together like tweezers. When you have some tiny particle in between the nanotubes, you have just grabbed it. Now you can move it around by moving around whatever you have the glass attached to.
Some interesting things to attach it to are:
- Scanning probe microscopes -you would attach it to the probe, thus making you able to make clear images of a miniscule object and physically manipulate it with just one toy.
- Various other probes separate from microscopes; you could do lots of things with these.
Diagram of nano-tweezers
You may have to resize your browser, and the diagram is not to scale.
Carbon Nanotube A
Glass | (Object, eg Alan Greenspan, goes here)
Carbon Nanotube B
Source: Nature 414, Nov 8 2001