Neural implant stimulation based on TiO2 nanostructured arrays; a multiphysics modeling verification

Exploiting of the nanostructure arrays as a promising candidate for excitation of neural cells has been analyzed. Based on the importance of the coupling effect between electrode and neuron, a multiphyscis modeling approach has been proposed. The model incorporates theoretically both structural effects (size, geometry) and electrophysiological effects. The system of equations for proposed model has been solved numerically using Finite Element Method for Poisson equation and Finite Difference Method for Cable equation. In this regards we have combined the system of equations in COMSOL platform with Matlab interface accordingly. We have analyzed the effect of excitation of neuron with an extra source of voltage pulse to evoke the action potential. We have performed the simulation for two different cases, an array of nanoelectrode and single microelectrode structure. The results of analysis indicate that nanostructure arrays are of enhanced properties in inducing the displacement currents to the structure in their vicinity. By applying the same voltage pulses on two structure electrodes, the excitation with nanostructure was culminated in evoking and propagation of action potential on the neuron structure. The results indicate that semiconductor nanotube structures are high-quality candidates for the excitation of neurons, not only because of the low-noise induced according to their surface area and non Faradaic nature of excitation, but also because of their unique properties in induction of displacement current according to their size and porous structure.