A multisite neural probe with simultaneous neural recording and drug delivery capabilities

This paper presents a novel method for fabricating silicon based planer microelectrodes with SU-8 embedded fluidic channels. A 7 mm long neural probe was fabricated with a 5 mm penetrating shank and a 2 mm × 2 mm base. One surface of the probe consists of eight 160 μm diameter wire bonding pads connected to eight 60 μm diameter electrode sites on 500 μm centers with eight 15 μm wires interconnects. On the opposite surface lies a 200 μm SU-8 embedded fluidic channel. The fluidic channel was constructed by utilizing two wavelengths of ultraviolet light: a higher wavelength (>365 nm) that penetrates the SU-8 completely to construct the fluidic channel walls and a lower wavelength (<;320 nm) that only penetrates the surface (<;60 μm) to fabricate the roof. The design was chosen for brachial plexus nerve implantation; however, since it was developed using photodefinable processes, the design can easily be adjusted for various applications.