Flexible electrode arrays for neurodynamic studies

A novel platinum electrode array with 100times100 micrometer² contact area on 3 mm long, 5 micrometer thin, flexible silicon cantilever beams that are mechanically and electrically impedance matched with lipid membranes was designed and fabricated using a bulk micromachining technique. Coatings with carbon nanotubes, carbon black, and silver epoxy reduced the electrode-saline solution resistance considerably. Coating with silver epoxy reduced the series electrode-saline resistance to around 5 kOmega at 10-100 mV and increased the electrodepsilas parallel capacitance by more than two orders of magnitude. Coatings with carbon black and carbon nanotube resulted in slightly higher reduction in electrode resistance and produces very stable electrodes over 6 months compared to the bare Pt and silver epoxy coatings. The array has been validated by wired, in vitro recordings from neurons, but is compatible with an existing wireless system that can send stimulation instructions and receive recording data.