By their very nature, microchips are little bitty things, but scientists wants to make them downright invisible – and they’re getting pretty close! A team from IBM just announced some solid progress in using carbon nanotubes to replace the transistors that currently allow microchips to process information. Because they’re about as conductive, they can carry an electric signal just like the silicon we use today but are a fraction of the same size. This ultimately means that you could fit 1 billion nanotubes onto a one square centimeter chip. One billion!This is how big that is:The trick is in the chipbuilding. At size this small, our existing tool kit is pretty useless, and so the team from IBM has come up with a way to assemble the nanotubes on the chips chemically or more less. A better word to use would actually be self-assemble since the scientists just dip the wafer into two different solutions and then let the reaction do the work. As the IBM team explained in a paper just published in Nature Nanotechnology, the top side of the wafer is coated in hafnium oxide and then a gridline distribution of silicon dioxide. Then, that side is coated with a chemical called 4-(N- hydroxycarboxamido)-1-methylpyridinium iodide (NMPI) which more or less acts as a glue for the nanotubes which are wrapped in a soaplike chemical, sodium dodecyl. When combined with the hafnium oxide side of the wafer, the carbon nanotubes arrange themselves in rows, and boom, the basic building blocks of a microchip are in place.“This new ability to accurately place individual, aligned CNTs at a high density enables the fabrication of a large number of single-CNT transistors,” the IBM researchers said in the paper. “Using the placement method, we fabricated arrays of CNTFETs (designed with one trench per channel of a device) and electrically characterized more than 10,000 CNT devices on a single chip.” While this process isn’t yet at the point where it can be used to manufacture chips, it’s 100 better than previous attempts. The researchers say they still need to increase the density ten fold for it to be viable, though.The carbon nanotube idea is only one of many new ideas for super small microchips. Just a couple of weeks ago, a team of researchers showed off their microchip-building technique that uses spider silk instead of silicon giving it the ability to dissolve in the human body. A few weeks before that, some folks came up with the ability to 3D-print objects on a molecular level, a breakthrough that could help solve some of the manufacturing challenges. To get much small than that, we’d have to break into the realm of quantum computing or something so futuristic we don’t even know about it, yet.Image via Flickr
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