TECHNOLOGY: Artificial Nano-Nerves

Over half a century ago, scientists discovered that the neurons in our brain use electrical signals to communicate and process information. Since that time, there has been a fascination with the possibility of using electrical stimulation to control brain processing - especially in cases where brain damage has left individuals with disabilities. Recent advances in labs at the University of Texas Medical Branch at Galveston (UTMB) and the University of Michigan have shown how nanoparticles may help bring significant advances in this so-called field of brain "prosthetics".

This process, which was published in an article in Nano Letters, involves placing many layers of ultra-thin films of mercury-tellurium (HgTe) coupled with positively charged polymer called PDDA, on a plate and coating the layers with materials designed to couple with a receiving neuron. When light of a certain wavelength hits the film, the HgTe compounds shoot electrons into the PDDA layers, producing an electrical current (see figure). This current can then be transferred into the connected neuron to create a neural signal, also known as an action potential.

One of the major advantages of this system is its "wireless" nature. Without a need for wires, these particles add a flexibility that may someday prove very useful in creating prosthetic limbs capable of responding to signals from our own brains. In addition, the responsiveness of these devices to light make them prime candidates for potential creation of artificial retinae. By tuning each device to a certain wavelength of visible light, scientists may someday be able to simulate color vision in a form transmittable to the brains of the blind or color blind.

(FIGURE from the article)