Okay, maybe not Art, but apparently engineering is taking a cue from life – human nerve cells to be exact.
A research team led by R. Stanley Williams, a professor of computer engineering at Texas A&M University, used the human axon as an inspiration for self-amplifying electric wires.
Ordinarily, the signal traveling along an electric wire gradually decays without the help of amplifiers or other such devices. Even the best wires and chip interconnects put up resistance to the flow of electrons, degrading signal quality over even relatively small distances. A 1-square-centimeter chip has about 10,000 repeaters to drive signals, according to Williams. That’s a problem for chip design.
But that’s not the case for axons that carry signals from our nerve cells, often over considerable distances. In human beings, the longest axons are about 1 meter long. In blue whales, the longest axons are about 30 m long, reaching the tips of their tails. Even along 30 meters, “the pulses arrive perfectly, according to Williams. That isn’t possible with electric wires.
So how do they do it? Axons are coated with a myelin sheath that insulates the axon. Gaps in the sheath allow negatively charged sodium ions and positively charged potassium ions to move in and out of the axon. As a result, voltage changes across the cell membrane and energy gets taken up by the electrical signal, amplifying it.
Williams and his team mimicked the axon, using a layer of lanthanum cobalt oxide with a 1 mm metal line on top. They biased the lanthanum cobalt oxide with a direct current and passed an alternating current signal through the metal.
The “neuromorphic” wire was a resounding success. Not only did the signal not degrade as it passed through this device, it came out the other side of the wire amplified by as much as 70 percent.
While a lot more research is necessary, Williams hopes that his work will eventually improve chip design.
The study was published in the September 11 issue of Nature.