- Open the box only touching the spool, never the wire itself.
o The tip of the wire is usually taped to the top of the spool, remove the tape carefully so you don’t stretch the wire and cut off the bent part.
- Lay the wire on a sheet of white paper (so you can actually see it) while unraveling the spool, without touching the wire itself. (Slide 1, Figure b)
o Be very gentle, do not tug on the wire, rather rotate the spool and let the wire come off on its own.
o If the wire doesn’t continue to unravel you can gently pull the tip so it starts to unroll again.
- Cut 18 wires 7-8 cm in length. (Slide 1, Figure c)
o This is for two boards/bundles which will have 9 wires on each board. They will also be mirror images of each other.
o Each bundle will have 8 channels, and one reference wire (and later on you will add a ground wire)
- Once finished with the spool, tape the loose end back to the top, then place it back in the box making sure the edge of the box doesn't touch the wire.
- Use fine forceps to line up the ends of the wires on one corner of the paper. (Slide 1, Figure e)
o Only touch the very end of the wires with the forceps.
- Pick up the matched ends of the wires carefully with your hands and arrange them in a bundle in the crease of your palm. (Slide 1, Figure f)
- Twist the wires together still only touching the very tips.
- Place the twisted end of the bundle onto double sided adhesive tape that is on a mobile stand/altoid box.
o Make sure the wires are adhering to the tape well, and that all the wires are together.
o It helps to put another piece of double stick tape over top of the twisted pieces to make sure they all stay together
- Dip a needle into liquid Zap glue and place a drop of the glue starting where the wires leave the double sided adhesive tape. Make sure the wires are glued together by gently touching them with glue on a needle.
o Not a lot of glue is needed, and too much can be bad- you don’t want too much glue all over the wires, just at the tip where they attach to the double sided tape.
- Cut all the microwires to the length of the shortest one making them even. Use very sharp scissors.
- Wait until the glue is dry before proceeding.
Scraping off the insulation
- Set up the wires so that the tips of the wires are on resting on a glass slide (Slide 2, Figure a)
- Open a NEW razor blade, and gently scrape along the wires.
o When you scrape with the correct amount of force you will be able to see flakes of gold coming off the wire, and you will be able to feel/hear the insulation being scraped off. (Slide 2, Figure c-e)
o If you push too hard on the wires, the tip of the wire will curl which will make it harder when threading through the green board later, so be careful.
- It helps to place the palm of your left hand on the altoids box with the double sided tape to keep it stable, then to use your index to hold the wires against the glass slide. (Slide 2, Figure b)
o Holding the wires down will help keep them from moving around too much while you are scraping, though they will move a little.
- Only scrape 4-6mm of the tip of the wires. (Slide 2, Figure c)
- Once you have scraped enough on the first side, flip it over.
- On the reverse side, scrape the insulation off on that side too.
- If the wires are now completely bare, they should look more silver than they did before, and they will also look thinner than the rest of the wire.
o This is sometimes hard to spot so don’t worry if you don’t see it. As long as you saw the insulation scraping off then that is fine.
- You don’t have to scrape all the insulation off, though it helps to get as much off as you can.
- Get a green board, and tape it onto an altoids box so that the two ‘arms’ are attached to the box, and the rest is hanging off the edge.
o Make sure all the holes are visible, not covered with tape, or that there is anything else in the holes. You might have to punch something out if you need too.
o It should be taped in a way that is stable, but not too difficult to remove.
- Now that you have the electrode wires taped onto one Altoids box, and the green board taped onto another Altoids box, you can arrange the two boxes in a way convenient for threading the wires through the holes on the green board. (Slide 3, Figure a-c)
o Make sure the two boxes are not too close to one another, but still close enough that there is enough wire length to go through the holes. Somewhere between 5 and 8 mm of wire should go through each hole.
- Setting up the right microscope magnification is very important. You want all of the holes to be visible at the same time, but still be close enough to see the tips of the wires.
- Set up the wires so that the wires are 3-5mm over the holes on the green board. This is a good distance so that you can easily see the holes, and see the tips of the wires. (Slide 3, Figure c)
- Cut a 10 cm long piece of ground wire using clippers (ground wire is too thick for the scissors, it will damage them).
- Make a little hook on one of the ends of the ground wire. (Slide 3, Figure f)
- Thread the bent end trough the furthest/biggest hole on the green board.
o You might need to figure out how to make it stay, because it tends to want to pop out.
- Now that you have all of that set up, you can start threading the electrode wires into the holes on the green board. This should be done using forceps, picking up the wires just 1-2 mm away from the tip and gently putting them into the holes.
o You won’t need to force the wire into the hole. You just need to guide it into the hole it will go the rest of the way on its own.
o If this doesn't happen, make sure the tip is not stuck or hitting something or bent, and gently push the wire down using the side of the forceps.
o You also might need to use the side of the forceps to move the wires left or right.
o Don’t squeeze the wires to move them, but simply hold them gently and move them.
- Make sure there is only one wire in each hole.
- Make sure that all the wires are the same length, by using a tooth pick to make sure there is a nice curve of the wires as they go from the taped box into the holes.
- Get a large-ish bead of gel glue on a needle tip, and spread it over the holes, making sure all of the holes are covered. (Slide 3, Figure d-e)
o You will need to have a lot more glue around the ground wire.
o The glue should be relatively thick around the wires.
o Move the needle around to the underside of the wires to make sure there is glue all the way around the wires.
- Put ZipKicker on the glue, making sure all of the glue is covered by it.
o I use the microscope to see how much zip kicker I am putting on the board.
- Remove the excess ZipKicker by absorbing it with a Kim wipe.
- Make sure there is no bubble in the glue. If there a bubble, just add more glue.
- After checking under the microscope that all the microwires and the ground wire are firmly glued to the green board, cut them free at the point where they meet the tape.
Finishing the Green board
- Free up the green board very carefully, making sure not to touch the wires. Turn it around and tape it back onto the Altoids box. The side with the glue should now be facing down towards the table. (Slide 4, Figure a)
- Use a toothpick to gently bend the microwires so that they are pointing towards you. (Slide 4, Figure b)
- Use clippers and clip the wires to the final length you will want them to be at. This should only be 2-3 mm or less (it should stay within the boundary of the gold plate). (Slide 4, Figure e)
- Using scalpel or forceps scrape the excess insulation off the wire.
o Scrape the wires while they are point at you, and then gently push them so they are pointing away from you. This should be the only movement you make with the wires. If you bend them too much they will break off.
o You should have already scraped most of the insulation off, but this is to be absolutely sure there is none left.
o The wire is very delicate, so all of this should be done extremely gently and carefully.
- It is very important that the wires are confined to the plates.
- Bend the ground wire so it is against the metal plate of the board. Clip off excess ground wire so that it is also confined to the plate. (Slide 4, Figure figure c-d)
- You have two boards that are mirror images of each other, each with 9 microwires, and a ground wire. (Slide 4, Figure f-g)
- Turn on solder iron, and get the solder plus from the refrigerator (Slide 5, Figure a)
- Turn on whatever air or gas system you have hooked up to the soldering iron.
- With the green board positioned such that the scraped wires are facing up, fit the black omnetics board so one prong/foot is over top each wire and covering the hole in the middle of the gold part. (Slide 5, Figure b)
o The black board will move while you are working with it, so don’t worry about it being exact right now.
- Put some solder on the needle and spread the solder on the tops of the wires and feet from the black omnetics board. (Slide 5, Figure c)
- When solder iron is hot, press the button to make hot air come out.
- Completely melt all of the solder. (Slide 5, Figure e)
- While pointing the air gun at one side of the board (Slide 5, Figure h-i) (so that the other side is still solid which will keep the black board in place) use needle to separate solder so that it is on only the metal parts.
o This is a very important step so make sure there are only humps of solder over each plate and that these humps are not touching
- There should be a bigger hump over the ground wire to cover the whole plate (including the small hole on the gold plate that the ground wires hole is on.)
- Common issues:
o Sometimes the ground wire is that it isn’t completely covered by the solder. Make sure that the ground wire is completely covered. (Slide 5, Figure j)
o Sometimes the ‘feet’ of the black board are sometimes lifted above the green board. When you are finished soldering and separating each channel, you can melt the whole thing, and push gently on the end of the black board using the needle to push the ‘feet’ down. (Slide 5, Figure k)
o If the microwires you have are too long, they may move around too much, and poke out from under the ‘feet’ and you will have to push them gently back under the feet. This is why making the wires short is helpful.
- When it is finished, you shouldn’t be able to see the outline of the ‘feet’. They should be covered with a hump of solder.
- When you are finished you might need to ‘squeeze’ off some of the extra solder. This is harder than you think because you need the ground wire to be completely covered.
- Turn off soldering iron and return soldering paste to the refrigerator, and turn off the air or gas.
- The finished product should have each channel is separate from the others, with each wire completely covered and not visible.
Pouring the microdrive molds
- Reset the chambers in the microdrive mold by pushing back the pin in the back of each individual mold so it is flush with the back
- Wipe off the screw to make sure nothing is stuck in the threads, and screw it back into the mold so that it ends at the middle (right over the pin). (Slide 6, Figure a)
- Place the smooth side of the canula into the mold, pushing it all the way in so it touches the end of the screw and have the rough/flattened side sticking out. (Slide 6, Figure b)
- Make absolutely sure the screw and pin meet at the middle. (Slide 6, Figure c)
- Pour some powder dental acrylic into the rubber bowl, and add the solvent.
o I usually fill up the rubber half full with dental acrylic (Slide 6, Figure d)
- When you make the dental acrylic, you want it to be pretty liquidy that it doesn’t form bubbles in the mold.
- For the first go through, fill the mold so that the liquidy solution flows to the bottom of the mold and just covers the screw shaft and the cannula shaft. Fill all the molds with this liquidy solution before you finish the mold. (Slide 6, Figure e)
- Once you have the liquidy part in all 10 molds, go back to the first one and continue to fill the molds with the solution now that it is hardening a little more.
- You don’t have to fill the mold all the way just yet, but keep filling the mold with the solution as it continues to harden.
- You will need to heap the solution on top of the mold because as it solidifies it shrinks, so you need to have the extra on top so the mold is whole when you take it out. (Slide 6, Figure f-g)
- Leave microdrive mold on horizontal plane and let it dry/harden for 24 hours.
- To take out the molds, use pliers to turn the screws. The pliers that work best for this are the blue handle ones.
o Use the small hole in the pliars to turn the screw. (There is only one groove on the pillars that fits the small screw head.)
- Make the first turn sharp and fast, and then continue unscrewing normally.
o You can tell you have successfully turned the first turn if the shaft becomes white, as well as a ‘crack’ sound it makes when you turn it. (Slide 8, Figure a)
o Be absolutely sure you are not bending the screw while you take it out, or are hitting the other screws, with the pliers, nearby when you turn the screw.
- Pull out the canula using a sharp first turn like you did with the screw, and then pull the canula the rest of the way out. (Slide 8, Figure d)
- Bang on back pin to push the mold out (Slide 8, Figure e)
- Break off excess dental acrylic. (Slide 8, Figure f-g)
- Look at the microdrive you just took out of the mold under the microscope.
- Make sure it has no bubbles touching or around the screw shaft or the canula shaft, no big bubbles, and that there is no separation between two shafts. (Slide 9)
o If it has any of these thing, it is a bad Microdrive and cannot be used and should be thrown out.
- Use the sharper more saw like blade on the Dremmel.
- Mark off 1.7cm on the 21gauge metal tube (Slide 7, Figure b)
o Use ruler and sharpie to mark the sizes
- Use sharp saw to cut the pieces
o Hold canula on an angle so it is being cut by the point of the blade (Slide 7, Figure c)
- Warning: the canula may become very hot from the friction of the saw, so if it does become hot, just wait for a few seconds then you can start again.
- Rotate around the marked place until it is cut
- You can smooth out the cut part now by holding the cannula perpendicular to the saw with the sharper blade though it may not be necessary. You can also start beveling the edges using the sharper blade. (Slide 7, Figure d)
- Change the blade to the smoother blade to completely smooth both ends, and continue to bevel the ends. (Slide 7, Figure e)
- Using the microscope, the exacto blade to scrape out the excess metal in the inside. (Slide 7, Figure f-g)
o Place the tip of the exacto inside the tube with the sharp end to the outside, holding the exacto at an angle (a right angle works best) to the tube so that the sharp edge cuts the metal.
o Scrape out the extra metal from the tube and smooth out the edges.
- Use black flat nosed pliars to flatten one end about 4mm. You might cut it later, to the exact size you will want it, but this is good enough for now. (Slide 7, Figure h)
- Pick out a microdrive
- Place the tiny screw set on screw driver and shave the end using the sharp dremmel blade so that it is flat. (Slide 10, Figure b)
- Coat the screw with release compound (Slide 10, Figure d)
- Check to make sure the screw goes all the way in (or as far as the screw driver will allow). (Slide 10, Figure e-f)
o Be sure it goes in straight- if it starts to go in crooked, unscrew a little and reposition it, then continue to screw it in. You might need to make a few little tweaks.
- Make sure you can screw it all the way to the bottom, and then unscrew the screw so the top of the screw is flush with the top of the microdrive. (Slide 10, Figure g)
- There should be some resistance, but not enough to keep you from turning the screw. You will know if there is too much resistance if it squeaks when you turn the screw.
o If it’s wonky/if the screw strips/if there is too much resistance, remove the screw (if you can) it is a bad microdrive and just throw it away.
- Add release compound to the cannula and make sure the cannula goes into the microdrive with some, but little resistance. You may need to use the pliars to push it all the way down. (Slide 10, Figure h-j)
o If you push too hard the cannula will bend, then you will have to throw away that cannula.
- Lower the microdrive screw all the way watching the cannula, to make sure the cannula does not twist too much. (Slide 10, Figure k-l)
o A little twist in the cannula (about a ¼ turn) is normal.
- Unscrew the screw so that it is once again flush with the top of the microdrive and push the cannula back in so that it is against the screw.
o If the screw is flush with the top and the cannula doesn’t touch, you can screw the screw in enough so that it touches the cannula.
o You can make sure they are touching by seeing if the cannula moves down a little while you are screwing down the screw. Don’t move the cannula down too much though.
- Take two boards that are mirror images of each other and place them on the connector mount. (Slide 11, Figure a)
o The glued portion should be facing away from each other, and the soldered parts should be facing each other.
o The ground wires should be connected with the ground wire threads on the connector block
- Use wire cutter pliers to cut the green board:
o Cut the two connecting sides around the big central hole. Cut so that the line you end up with is straight and parallel to the black boards. (Slide 11, Figure b-c)
§ Also make sure there are no jagged edges.
o Cut the ‘arm’ that is away from the ground wire so that it is flush with the black board. Don’t just cut the arm halfway, but cut it so that the clipper is parallel to the black board. (Slide 11, Figure d)
§ Careful with this step that you don’t cut the glue. If you cut the glue the glue will come off taking the wires with it then you have to start over again.
§ Cut off only the bottom/lower arm (the side the microdrive is going to be glued too, which is typically opposite the ground wires) so that you can still clip it to your stand.
- Make sure the black connectors are as closely aligned as possible.
- Make the ground wires are on the bottom and that the side the microdrive is going to be glued to is facing up.
- Use the gel glue: place it in between the two black boards, so that it is completely through the opening between the two. (Slide 12, Figure a)
o You want to seal off the open area between the black boards so that once it is implanted nothing can leak through.
- Place another glob of the glue on the top where the microdrive will be. (Slide 12, Figure b)
o It doesn’t matter which side of the microdrive you glue to the black boards
- Hold the microdrive against the black boards so that the spatula is sticking out the end where you just cut away the green board. (Slide 12, Figure e)
o Be sure the microdrive is straight/parallel to the black boards and not crooked.
- Using your other hand add ZipKicker everywhere: Add to where the microdrive is, and where ever else you put glue. (Slide 12, Figure d)
o Only remove your hand from the microdrive when you are sure the microdrive is stable.
o Don’t glue your finger to the microdrive.
- Soak up the excess ZipKicker with a twisted kim wipe.
- Add more glue to the sides of the microdrive just to make sure the microdrive won’t come off. (Slide 12, Figure d)
- Cut a 2mm long piece from the grooved board using a razor blade (Slide 13, Figure a-b)
o Make sure your cut is parallel to the other side, and perpendicular to the grooves
o It helps to use the middle of the razor. You will need to push hard, but make sure the cut piece doesn’t fly away.
- Cut metal sheet so that it is a little wider than the board and about 3mm long. (Slide 13, Figure c-d)
- Using only a very small amount of the gel glue, glue the two south corners of the metal sheet to the glass slide. (Slide 13, Figure e)
o Glue the corner, not the straight edge.
- Use zip kicker to dry the glue, and use a rolled kim wipe to soak the excess kicker
- Use tweezers to figure out which way the grooves are up.
o One side will be completely flat and smooth and the other you will feel bumps.
- Place the grooves on the metal sheet so that the thicker side with no groove is to the right and so that there is a little part hanging off the end of the metal sheet. (Slide 13, Figure f)
- Using the liquidy glue, carefully glue the grooved board onto the metal sheet (Slide 13, Figure g)
o When gluing be careful not to put too much glue so that it goes into the grooves.
o When the glue is done correctly, you will be able to see the glue move under the board.
- Let it completely dry before you continue.
o It is best not to use the ZipKicker because that tends to shrink the glue, which would make it more likely that the grooved board would come off.
- Use razor to flip the metal piece over by cutting away the glue on the corner. It should come up pretty fast.
- Place metal sheet with the grooved board side down, and place glue in the crease between the grooved board and the metal sheet. (Slide 13, Figure h)
o You can glue the corners again if you want to, though it is not necessary.
- Make sure it doesn’t glue itself to the slide while you are gluing the back.
- Take one of the grooved board/metal sheets and glue the two south corners to the slide. (Slide 14, Figure a)
- Use zip kicker to make sure the glued corners are solid
- Use twisted kimwhipe to soak up the excess zip kicker. Make sure to get the excess zip Kicker off the grooved board as well.
- Make sure all the wires are separated and that they aren’t glued together
o You can cut the glued part off, but it would be better if the wires were long.
- Finagle the black board such that one of the bundles of microwires is straight over the grooved board. (Slide 14, Figure b)
o I usually have the microdrive on top, and tape the green arms to the slide (with the ground wires being taped down too).
- Set up one of the Helping Hands soldering tools so that it will be able to hold the wires you are not working with to the side. (Slide 14, Figure c)
- Look at the arrangement of the wires on the green board and choose the first one (this will either be the one closer to the microdrive or near the ground wire.
o Figure it out so that the reference wires (which are the closest to the ground wires) will be in the center.
- Use modified wooden sticks/needles/whatever works for you to place the wire into the groove. (Slide 14, Figure d)
o Modified so that the tip is sharp and will be able to be placed over one groove at once without spreading the glue into the other grooves.
- Use liquid glue to glue the wire into place.
o The trick is to use as little glue as possible, but to use enough so that the wires will be firmly glued into the grooves so that they won’t pop out.
- Be sure you are not getting any glue in the other grooves
o Glue in the other grooves makes it a lot harder to put the rest of the wires in later.
o If this does happen, you can take a disposable exacto and scrape out the glue. This takes a lot of careful movements, because if you push too hard the board will cut.
- Since there are 18 wires, and only 17 grooves one of the wires will have to be glued to the top where the thicker part is. (Slide 14, Figure g)
o Use the gel glue and place just a small line on the area, then finagle the wire so that it is straight.
o The glue will dry fast, so you have to be fast about putting the wire in the correct place.
o The part that matters the most for this wire is that the wire is straight and parallel to the other wires when it come out of the grooved board. Where it comes into the grooved board doesn’t matter as much.
- Look at the arrangement of the order of the wires and get the next wire. Be sure you are not pulling on the wires you just glued.
- Place the other wires back behind the helping hands.
- Continue until you have finished all the wires for that bundle. (Slide 14, Figure d-j)
- Place excess glue on the 9 wires you have just glued, and wait until that glue is dry.
o Be sure none of this glue gets into the next grooves that have no wires yet.
- Carefully turn the electrode so that the second bundle is now across the grooved board.
- You want the wires that you have already glued into the grooved board to have some slack so they are not tight and so that they won’t pop out of the grooves.
- Continue until all wires have been placed into the grooves.
- Continue to place glue onto the grooves, so that a mound of glue forms on the top.
- You can also place more gel glue on the left side to make sure the wire on the let doesn’t come out (because that is the most likely wire to come out).
- Once there is a big mound of glue on the wires, you can use the razor to remove the metal sheet from the glass slide. Make sure you don’t separate the grooved board from the metal sheet.
- Let the glue dry for 24 hours before going onto the next step.
Attaching grooves to spatula:
- Set up the electrode on the connector mount such that the microdrive is on the bottom.
- It helps to twist the wires a few times so that the wires are all in the same general area. (Slide 15, Figure b-c))
o I use forceps to twist the wires, and my fingers to hold the metal sheet. If you do this just make sure you are not bending any of the wires.
- Place a glob of glue on the spatula (while holding the metal sheet with your fingers), and using the forceps carefully lower the metal plate onto the glue. (Slide 14, Figure d)
o I use the forceps to hold the metal plate against the spatula, just be careful you don’t glue the forceps between the metal plate and the spatula.
- Use Zip Kicker to solidify the glue. (Slide 14, Figure f)
- Use a twisted kim wipe to soak up the excess zip kicker.
- Turn the electrode around, and put more glue around the spatula where it touches the metal sheet. (Slide 14, Figure e)
- Get down the voltmeter and make sure it is working by putting the two prongs together- you know it is working when you hear a sound.
- Test each channel with all the others by holding the black prong against the channel to test, and moving the red to the other channels.
- It should only beep when it is the same channel on both prongs. Otherwise there is crosstalk between those channels and that they are bad.
- To test the ground wire, hold the red prong against the ground wire itself, and the black against the single screw on the connector block
- Move the ground wire around while keeping contact with the red prong. If it beeps it is good.
- Turn around the block around and do the same thing for the other set of bundles.
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