1. A microelectrode device for receiving and sending electrical signals within a nervous system of a subject, said microelectrode device comprising: a substantially-flexible planar shaft having a polymer-based substrate made of at least two flexible, planar thin-film polymer layers and at least one planar metallic layer, the substantially-flexible planar shaft having a proximal end and a distal end; a plurality of electrode sites disposed on the shaft, at least one of the plurality of electrode sites operable to output a stimulating signal to the nervous system and at least one of the plurality of electrode sites operable to record an electrical signal within the nervous system; at least one fluidic channel extending within the substantially-flexible planar shaft from the proximal end to generally the distal end, the at least one fluidic channel configured for the delivery of fluid to the nervous system, a fluid delivery system fluidly coupled to the at least one fluidic channel, the fluid delivery system configured to output the fluid to the at least one fluidic channel; a stimulating system operably coupled to the at least one of the plurality of electrode sites configured to output the stimulating signal; and a recording system operably coupled to the at least one of the plurality of electrode sites configured to record the electrical signal within the nervous system; wherein the outputting of the stimulating signal to the nervous system and the recording of the electrical signal within the nervous system are configured to occur simultaneously with the fluid being delivered to the nervous system.