The structure of Aleksandr Noy's new transistor is unimpressively simple: just a carbon nanotube connecting two metal electrodes. But what makes it special is what he and his team use to control it: adenosine triphosphate (ATP), the fuel from our own cells. The project, published in a study in Nano Letters, achieves a key step in unifying man and machine. The way it works: An insulator coats the ends of the nanotube, but not the middle—it's left exposed.
The entire device is then coated again, this time with a lipid bi-layer similar to those that form the membranes surrounding our body's cells [New Scientist].
Finally, the team poured a solution of ATP plus potassium and sodium across the transistor. That created an electric current, one that was stronger the more ATP they poured.
The magic is in the lipid bi-layer, which contains an ATP-sensitive protein that serves as a kind of ion pump when ATP is present. The lipid hydrolyses ATP molecules, with each occurence causing three sodium ions to move one way through the lipid and two potassium ions to move the other way, netting one charge across the bi-layer to the nanotube [Popular Science].
Noy claims to have created "the first example of a truly integrated bioelectronic system," New Scientist
says. And as simple as the transistor is, the idea behind it—harnessing the energy already in our bodies to power electronics
—will be one of the keys to creating battery-free devices that monitor our cells, connect to our brains, or do things we won't think of until we've (finally!) got nanodevices hooked up to our brains. Related Content: DISCOVER: Future Tech: The Carbon Nanotube Grows Up
Image: Aleksandr Noy et. al.