After digitally designing and printing the micro drive, attach two screw attachments to each tetrode advancing screw one above and one below the ridge. Hold the screw attachments together with gel cyanoacrylate. Ensure that the screw attachments do not move in the longitudinal axis of the screw, but can rotate freely with minimal resistance.
Extend each polyamide section through the output holes on the micro drive cannula by a few millimeters. Secure the polyamide to the cannula using a clean 30 gauge needle in small amounts of liquid cyanoacrylate, being careful not to let it enter the inside of the polyamide tube. Retrieve the large polyamide tubes from the top of the micro drive cannula and pass them through the large polyamide holes in the micro drive body.
Gently push the micro drive cannula and micro drive body together until they are adjacent and the cannula body attachment tabs interlock. Secure the micro drive body and the micro drive cannula with cyanoacrylate. Using a new sharp razor blade, severe the large polyamide tube ends extruding from the bottom of the cannula output holes, ensuring the cut is precisely at the cannula's base, making the tubes and cannula bottom flush.
With sharp scissors, cut the large polyamide tubing just above the edge of the inner rim of the drive body at a 45 degree angle. Cut small polyamide tubing into four centimeter long sections. Pass the small polyamide sections through the large polyamide tubing already mounted in the micro drive and ensure that excess small polyamide tubing protrudes from the top and bottom.
Secure the small polyamide tubes to the screw attachments with cyanoacrylate. Avoid letting any cyanoacrylate enter the large or small polyamide tubes. Using a new sharp razor blade, sever the small polyamide tube ends extruding from the bottom of the cannula holes.
Ensure the cut is at the cannula's base and clean with nothing blocking the polyamide tube hole. Then use sharp scissors to cut the top of the small polyamide. a few millimeters above the top of the screw attachment at a 45 degree angle, ensuring the cut is clean.
Using ceramic or rubber tipped forceps, carefully pass a tetrode through one of the small polyamide tubes, leaving approximately two centimeters protruding from the top of the small polyamide tube. Secure the tetrode to the top of the small polyamide tube with liquid cyanoacrylate. Retract the screw until it is near the top of the drive.
Grab the tetrode wire protruding from the bottom of the drive and gently kink it at the point where it emerges from the cannula. Fully advance the screw into the drive. Using sharp scissors, cut the tetrode wire just above the kink.
Then inspect it under a microscope to ensure the cut is clean and the metal of all four tetrodes is exposed. Finally, connect each electrode of each tetrode to the appropriate port on the electronic interface board. Tightly wind one bone screw with a thin, highly conductive wire that will be ground and attached to the electronic interface board.
