PROJECT TITLE :

PEDOT-CNT-Coated Low-Impedance, Ultra-Flexible, and Brain-Conformable Micro-ECoG Arrays

ABSTRACT:

Electrocorticography (ECoG) is becoming a common tool for clinical applications, such as preparing patients for epilepsy surgery or localizing tumor boundaries, as it successfully balances invasiveness and information quality. Clinical ECoG arrays use millimeter-scale electrodes and centimeter-scale pitch and cannot exactly map neural activity. Higher-resolution electrodes are of interest for both current clinical applications, providing access to a lot of precise neural activity localization and novel applications, like neural prosthetics, where current information density and spatial resolution is insufficient to suitably decode signals for a chronic brain-machine interface. Developing such electrodes is not trivial as a result of their tiny contact area will increase the electrode impedance, which seriously affects the signal-to-noise ratio, and adhering such an electrode to the brain surface becomes essential. The foremost easy approach needs increasing the array conformability with flexible substrates whereas improving the electrode performance using materials with superior electrochemical properties. In this paper, we tend to propose an ultra-flexible and conformable polyimide-based mostly micro-ECoG array of submillimeter recording sites electrochemically coated with high surface area conductive polymer-carbon nanotube composites to boost their brain-electrical coupling capabilities. We have a tendency to characterized our devices each electrochemically and by recording from rat somatosensory cortex in vivo. The performance of the coated and uncoated electrodes was directly compared by simultaneously recording the identical neuronal activity during multiwhisker deflection stimulation. Finally, we have a tendency to assessed the effect of electrode size on the extraction of somatosensory evoked potentials and located that in contrast to the conventional high-impedance microelectrodes, the recording capabilities of our low-impedance microelectrodes improved upon reducing their size from zero.2 to zero.one mm.