I studied FETs, BJTs, and diodes for a year for my engineering degree, so I can mostly read and understand this article. I don't understand a few things. Some

I studied FETs, BJTs, and diodes for a year for my engineering degree, so I can mostly read and understand this article. I don't understand a few things. Some carbon is put into a furnace with an inert gas, and the output is a bunch of nanotubes. Some conduct like metal, so they can't be used as transistors. Others have a band gap, and these can. I guess it's something to do with the lattice orientation. Now, imagine that I had a bunch of straws, and a block with straw slots on the top. I can think of no way to randomly disperse the straws over the block to get perfect alignment. Somehow, the straws end up with good connections to a source and drain, ready for a gate to be wrapped around them. Deposition of the straws on the substrate appears to be performed both in gaseous and liquid, but the straws must be made elsewhere. This is completely mistifying.