Carbon nanotubes are a promising material for making display control circuits because they're more efficient than silicon and can be arrayed on flexible surfaces. Until recently, though, making nanotubes into transistors has been a painstaking process. Now researchers at the University of Southern California have demonstrated large, functional arrays of transistors made using simple methods from batches of carbon nanotubes that are relatively impure.When the industry gets this worked out we will have much faster transistors capable of very high heat dissipation. Wouldn't it be nice to have high power electronics that was loafing along at 200°C?
And the process control for making carbon nanotube and graphene materials is in its infancy the results are looking better all the time.
Single-walled carbon nanotubes can be classified as either metallic or semiconducting, depending on their conductivity, which is determined by their chirality. Existing synthesis methods cannot controllably grow nanotubes with a specific type of conductivity. By varying the noble gas ambient during thermal annealing of the catalyst, and in combination with oxidative and reductive species, we altered the fraction of tubes with metallic conductivity from one-third of the population to a maximum of 91%.Carbon nanotube conductivity has been measured to be around 5X that of copper. Think of what could be done with low weight, high strength, high conductivity wire. Motors. Transformers. Transmission lines. Antennas. etc.
Fortunately there have been some breakthroughs in the wire making area.
A new method for assembling carbon nanotubes has been used to create fibers hundreds of meters long. Individual carbon nanotubes are strong, lightweight, and electrically conductive, and could be valuable as, among other things, electrical transmission wires. But aligning masses of the nanotubes into well-ordered materials such as fibers has proven challenging at a scale suitable for manufacturing. By processing carbon nanotubes in a solution called a superacid, researchers at Rice University have made long fibers that might be used as lightweight, efficient wires for the electrical grid or as the basis of structural materials and conductive textiles.So my question is: with all the money going out to the bankers why isn't more being spent on science like his that will actually make a difference?
Others have made carbon-nanotube fibers by pulling the tubes from solid hair-like arrays or by spinning them like wool as they emerge from a chemical reactor. The problem with starting from a solid, says Rice chemical engineering professor Matteo Pasquali, is that "the alignment is not spectacular, and these methods are difficult to scale up." The better aligned and ordered the individual nanotubes in a larger structure, the better the collective structure's electrical and mechanical properties. Using the Rice methods, well-aligned nanotube fibers can be made on a large scale, shot out from a nozzle similar to a showerhead.
Posts
