Multi-channel microelectrode array for cortical recording and stimulation: Fabrication and modification

The fabrication of silicon-substrate multi-channel microelectrode arrays for single neuron recording as well as modification of two materials to optimize the neural tissue-electrode interface were investigated. By use of multi-project wafer (MPW) model, six kinds of microelectrode arrays with different recording sites arrangement were simultaneously fabricated from one 4-inch wafer. To improve electric characteristic and biocompatibility, conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and multi-wall carbon nanotube (MWCNT) were used to modify the surface of microelectrode. The modified microelectrode exhibited better electrochemical characteristics, including a particularly high safe charge injection limit and low electrode impedance, as well as high signal-to-noise ratio in vivo. All of these characteristics are desirable for an implantable neural microelectrode and the modification method can be widely used to modify other neural interface devices.