By placing axons into polymeric microchannels hosting embedded electrodes the extracellular amplitude of action potentials is greatly increased, allowing for robust recording and noise suppression. We are developing such an electrode interface to record electrical activity from bladder afferents to restore bladder control in patients suffering from spinal cord injury. Here we describe our microchannel electrode interface in terms of design, microfabrication and electrode characteristics and report on in vivo bladder function after implantation of teased dorsal rootlets within microchannels.