Micro-Reaction Chamber Electrodes for Neural Stimulation and Recording

Biocompatible electrodes with smaller geometric area are preferred to improve the selectivity of the neural recording and stimulation applications. We introduce the concept of a micro-reaction chamber (mu RC) in which a volume within the electrode back plane is used to confine and sequester the electrochemical reactions used for charge passage. The mu RC electrode design helps decrease impedance and improves the charge storage capacity without altering the geometry of the active site. Here we demonstrate that mu RC electrodes fabricated from 50 mu m diameter microwire have significantly improved charge storage capacity and lowered impedance at physiologically relevant frequencies in phosphate buffered saline solution compared with other designs.