Micro-Molded Cannulae for Intracochlear Infusions in Small Rodents

The design, fabrication, and testing of micro- cannulae with integrated insertion stops is presented. The micro-cannulae were engineered through the use of a silicon micro-mold fabricated via bulk-silicon micro-machining techniques. The use of microelectronic fabrication techniques allows precise control of three critical parameters, insertion depth, interface contact area, and tubing out of round. Worst case variations were found to be 5mum for insertion depth, 502mum² for interface contact area, and 7% for tip out of round. Histological evaluation revealed the cannula to be located correctly within the basal portion of scala tympani.