Figure 1: Schematic illustration of the flexible tubular microelectrode and the corresponding fabrication processes.

(a) The construction and multi-function illustration of the flexible tubular microelectrode, comprising multi-channel electrode sites for electrical stimulation/recording and fluidic channel for drug delivery. (b) The fabrication process of the tubular microelectrode, mainly including: fabrication of parylene thin film microelectrode, wrapping and gluing on the polyimide capillary, and electrochemical deposition of conducting polymer.