A transverse intrafascicular multichannel electrode (TIME) to interface with the peripheral nerve.

Many different concepts of peripheral nerve interfaces have been developed over the past few decades and transferred into neuroscientific or clinical applications with varying degrees of success. In this study, we present a novel electrode design that transversally penetrates the peripheral nerve and is intended to selectively activate subsets of axons in different fascicles within the nerve. The "transverse intrafascicular multichannel electrode" (TIME) has been designed and fabricated using the micromachining and patterning of a polyimide substrate and insulation material and platinum electrode sites. In vitro characterization of the electrodes were carried out to determine the electrochemical transfer characteristics during recording and stimulation. Acute implantations were performed in the sciatic nerves of rats and recruitment curves were determined. Results indicated selective stimulation of different fascicles with graded recruitment. Future studies will address chronic implantation to investigate the reactions on the material-tissue interface and the long-term behavior and recruitment properties of the TIMEs.