Researchers at the University of Texas Southwestern Medical Center have developed a method to coat neural electrodes with carbon nanotubes. The technology has been tested on a bunch of mice and one monkey, and the findings show a higher signal to noise ratio when reading voltages, and more efficient and localized signals when stimulating the brain.
From MIT Tech Review:
Electrodes are placed in a water-based solution of carbon nanotubes; when a small voltage is applied to sites on the electrodes, carbon nanotubes localize there and can be fixed. Joseph Pancrazio, a neuroscientist at the National Institute of Neurological Disorders and Stroke, says that Keefer’s electrode modification “is something that can be done readily.” This means that other labs experimenting with neural prosthetics are likely to adopt the technique. By contrast, Pancrazio says, other methods for interfacing carbon nanotubes with neurons have required the use of special substrates and must be done at very high temperatures.
Pancrazio says that the nanotube coating might enable researchers to make smaller electrodes that cause fewer side effects. Using conventional electrodes for deep-brain stimulation, Pancrazio says, “you end up stimulating not only the area of interest but also other regions, leading to speech dysfunction and other problems.” The ideal electrode would be small enough to interact with only a single neuron. But when electrodes are miniaturized, their impedance increases and their performance decreases. Electrodes coated in carbon nanotubes might be more amenable to miniaturization.
More at MIT Technology Review…
Image: In these scanning electron microscope images, electrodes coated with carbon nanotubes, like the one on the right, are more conductive and better at interfacing with nervous tissue. The electrode on the left is bare. Credit: Edward Keefer
