Bristlebot Bugs

Activity setup:

1. Remove the toothbrush end from your kit. The bristles of the toothbrush will face down on your bristlebot bug and glide across the floor.
2. Peel off one side of the paper covering from a double-sided sticky tab. Attach it to the top of the toothbrush head, and then peel off the other side of the paper covering.
3. Attach the vibrating motor to the lower half of the sticky tab near the handle end of the toothbrush. Only attach the motor to half of the sticky tab; you’ll need the other half for step 5. Make sure that the wires are pointing towards the front of the toothbrush head. Use an elastic band to secure the motor in place.
4. Take the exposed metal part of the motor’s red wire and attach it to the positive (+) side of the 3V battery. Use tape to secure the wire, or position it between the battery and the double-sided sticky tab on the top of the toothbrush.
5. Attach the battery (with the positive side facing down) to the upper half of the sticky tab near the bristle end of the toothbrush. Secure it with an elastic band. Place the toothbrush with the bristles facing down to make sure it does not fall over once the motor and battery are attached. Adjust the position of the motor and battery if needed.
6. Use pom-poms, pipe cleaners, googly eyes or other craft materials to decorate your bristlebot bug! Be sure to leave some space on the negative side of the battery to complete your circuit (see step 7).
7. Complete the circuit by attaching the blue wire from the motor to the negative side of the battery. Use tape or a sticky tab to secure the wire in place. Once the circuit is completed, the motor should immediately begin to vibrate.

Experiment

There are many ways to experiment with your bristlebot bug! Here are a few things to try:

• The way the bristlebot bug moves will change depending on where you position the battery, motor and decorations. What happens if you move them closer together? Farther apart? What if they are not centred on the toothbrush?
• Try placing your bristlebot bug on different surfaces. How does it move on carpet versus harder floors? What happens if you put it on top of a thin layer of salt or flour in a tray?
• Try creating bristlebot bug art. Dip the toothbrush bristles in paint, and then place the bug on a large piece of craft paper and see what happens!

How does it work?

Your bristlebot bug contains a circuit. A circuit is a complete path that electricity can flow through. Electricity can be used to power different things, like a light bulb, a buzzer or a motor like the one in your bristlebot bug.

The source of electricity in your circuit is the battery. The positive (+) and negative (-) sides of the battery are connected to the motor through wires made of a type of material that lets electricity pass through them easily; this type of material is called a conductor. When both wires are connected to the battery, electricity can flow through the circuit and power the motor, making your bug vibrate and move.

The circuit you created is closed or complete. If you disconnect or detach a wire, you will create a break in the circuit, making it open. Because electricity cannot flow through an open circuit, your bug will stop moving.

The motor in your bristlebot bug is the same type of motor that is used to make cell phones vibrate. It contains a tiny offset weight. When electricity flows through the motor, it spins very quickly, which causes the off-centre weight to wobble. The motor spins so quickly that the wobble feels like a vibration. The vibration travels through the toothbrush bristles, making your bug travel around.