Optoelectronic stimulation of the brain using carbon nanotubes

This paper presents the simulation results of a novel technique to stimulate the brain using a carbon nanotubes (CNT) based optically activated stimulator. This technique could be a promising alternative solution to overcome the limitations occurring in the conventional electrical stimulation of the brain and the newly developed opto-genetic stimulation. In this technique, the CNT stimulator, which generated an electrical current when exposed to light, was implanted in the brain. This current stimulated the nearby neurons to generate an action potential. The simulation results illustrated that a single-wall carbon nanotube of 50 nm² size could stimulate a 40 μm² area of the brain, whereas a multiwall carbon nanotube could cover a 12 μm² area of the brain. Additionally, simulations were also performed to determine the optimal shape and appropriate coating material for commercial optical stimulators to maximize the stimulation efficacy in the brain.