Preparation

Before you begin, you should be comfortable using the required tools of this build. One RoboRoach electrode array will typically take 15 - 30 minutes. Follow the safety guidelines of your equipment, such as wearing safety glasses when using the wire cutters and practicing safe soldering techniques. To set up, get your tools out and make sure you have all of the necessary components. Feel free to email us at hello@backyardbrains.com if you need help sourcing any of the components or have other questions.

Tools you'll need:

• The "DIY RoboRoach Electrodes Procedure" (below). This is also available as a downloadable PDF and also as an instructional video (coming soon!).
• Soldering iron with a fine-point tip
• A small diameter solder (~0.015” dia.)
• Wire cutters
• Scissors
• Straight forceps tweezers
• Silly putty
• A ruler
• Sand paper (~100-150 grit)
• Safety glasses or goggles

 

Components you'll need:

• 0.003” bare / 0.0055” coated Silver wire
• 0.1” header male connector
• 0.1” header female connector

 

Essential skills:

• Comfortable with a soldering iron
• Comfortable with fine forceps
• Comfortable with a lighter
• A steady hand
• Good eyes and/or a trusty magnifying glass

 

Procedure

Step 1: Prepare the header (connector)

With wire cutters, cut a triplet (3-pins) female header. Wearing safety glasses for this step is recommended. There is a potential that parts or fragments become a projectile when cut free. Sticking the soon-to-be free portion in silly putty before cutting can help prevent flying objects.

Insert a male header (at least 3 pins long) into the triplet female header you just cut. This prevents solder from wicking down the socket.

Rough up both sides of the female header with sandpaper. This will help the super glue and hot glue stick.

Position the header in silly putty with the pins of the female header point up.

 

Step 2: Prepare the electrode wires

With scissors, cut 4 lengths of 1.5” long silver wire.

Using a lighter, carefully burn away ~1/8” of the wire’s insulation. Start with the flame several inches away and slowly move closer until just the coating melts away. Don’t hold the flame too close as this will also melt away the silver wire. This is made easier if you reduce nearby drafts, so that the flame doesn’t flicker. Repeat this on one end of each of the 4 wires.

Using your tweezer (forceps), make a small hook with the uncoated end of the silver wire that you just exposed.

Place the “hook” around a header pin. Tamping down the wire into the silly putty with a finger will ensure that the wire holds its placement when placing the others.

Repeat this once for each pin and twice for the center pin.

 

Step 3: Soldering

Solder the wires to the 3 pins of the header. Best to use a small-diameter solder and a fine-point soldering iron to be precise. If you overheat the pin or touch the exposed silver directly, it will melt and you will have to redo that wire from step 2.

 

Step 4: Finishing your electrodes

Now you should have two solo wires on the left and right pins; one pair of wires on the center pin. One at a time, with a light tugging force, pull the left and right wires and bend them off to the sides. A light tug is to test for a reliably strong solder joint and bending them out will get them out of the way for the next step.

Take the center pair, pinch it with one hand, and twist the header with your other hand. The goal here is to make the wires twist around each other neatly.

Next, using your lighter again, burn off 1/8” of insulation from the free ends of all three wires. Notice a “ball” of silver on the end of some of the wires.

Using your scissors, carefully snip the ends of the wires to remove the small balls. This will make it easier when implanting the electrodes during the RoboRoach surgery. The ends should be trimmed flush and look nice. It is important that each wire has ~1/8” of insulation exposed when all finished.

 

Step 5: Testing your electrodes

Repeat the "tug test" to make sure the silver wire will not easily break from the female header. You can also use a multimeter to verify your solder joint.

If your electrodes passed the test, Congratulations! They are ready for your next RoboRoach Surgery!