Microchannel electrodes for recording and stimulation: in vitro evaluation.

Previously we reported a finite-element model that predicted that microchannels could be sensitive recording devices, amplifying the extracellular signal as action potentials pass through them, and making recording independent of node of Ranvier location. Here, we present an in vitro experimental study that validates these predictions and also demonstrates that microchannel electrodes can be highly efficient stimulators. Several aspects of whole-nerve cuff technology, including noise-reduction techniques and unidirectional stimulation methods, are readily transferable to this small scale. If axons can be persuaded to regenerate in large numbers through narrow channels, the results presented here suggest that a regenerative microchannel array could be used to produce an in vivo peripheral nerve interface with a high-resolution for both recording and stimulation.