Self-Closed Parylene Cuff Electrode for Peripheral Nerve Recording

We have designed, fabricated, and characterized a self-closed parylene cuff electrode for peripheral nerve recording, whose curliness and closeness is realized by the difference in self-stress of different parylene layers due to the heat treatments. Compared with the conventional cuff electrodes, the self-closed structure without any additional mechanical locking structure minimizes the mechanical structure of the cuff electrode. Moreover, the self-closed structure made of thin and flexible parylene film minimizes mechanical damage to the nerve and the surrounding tissues. The zero insertion force interface facilitates the connection of 16 channels with external circuits through the integrated parylene bonding pads. To reduce the impedance and increase the charge storage capacity of the electrode, the electrodeposited iridium oxide film is electrodeposited on the electrode sites. Using the fabricated self-closed parylene cuff electrode, acute neural recoding of 16 channels was performed on the rat sciatic nerve to verify the capability of recording the neural activities. The present self-closed parylene cuff electrode is promising to be used as an neural interface for peripheral nerve recording.