Flexible multi-channel microelectrode with fluidic paths for intramuscular stimulation and recording

Biomedical microelectrodes play a significant role in motor paralysis recovery caused by spinal cord injury (SCI). As most researchers focused on implantable microelectrodes with multiple functions for neural studies and application, we developed flexible intramuscular microelectrodes integrated wire electrodes for functional electrical stimulation (FES) and electromyogram (EMG) recording with micro tube channels for fluidic drug delivery. The electrodes were electrochemically deposited with conducting polymer (PEDOT/pTS) coating to improve the electrode performance including electrochemical impedance and charge storage capacity (CSC). Moreover, the excellent mechanical and electrochemical stability of PEDOT/pTS coated electrodes was verified by withstanding ultrasonic bath and experiencing repeated cyclic voltammetry (CV) scan. Furthermore, the fluidic property of the micro channels of electrodes was investigated to be suitable for intramuscular drug delivery. In addition, electrophysiological experiments in vivo comprising FES and EMG recording were performed to evaluate the practical application of flexible intramuscular microelectrodes. As a consequence, the developed multi-functional intramuscular microelectrodes are suitable for intramuscular implantation and electrophysiological application, and open a new gate for future researchers on intramuscular motor prostheses for paralysis recovery.