This weekend, Coventry Makerspace took part in the Festival of Imagineers, which celebrates the creative use of design, engineering and technology. We were there to introduce kids to making, and these fun, cheeky little bristlebots were just what we needed to inspire the robot engineers of tomorrow! Quick and simple to build, but amazing enough to capture young imaginations, these were a real hit. The kids and parents loved them, we adult helpers had a great time, and the bristlebots conquered Coventry... next stop, the world!

Step 1: Gather Materials

The quantity of materials will depend on the the number of bristlebots to be made... we took enough to build 100 and ran out of kits long before we did kids to build them. You will need:

Toothbrushes (cheap ones are absolutely fine)
Button cell batteries
Small vibrating motors (those designed for mobile phones / pagers are ideal)
Double-sided tape Insulating electrical tape in the colour of your choice
Googly eyes, pipe cleaners and stickers (to decorate)

You will also need some very basic equipment:

Side cutters
Wire strippers
Scissors

Safety Notes:

Safety when working is always important, but more so when working with the public and/or kids! Health and safety is not about being a killjoy, it is about being aware of risks so that they can be reduced or mitigated.

Batteries can be a hazard if ingested. Educate children that components are not toys and should never be put in or near the mouth.
Many of the small motors we looked at had exposed components that move or spin. While these are good to show kids how the motor works, they are not good from a safety point of view! Only use motors that are fully contained.
Children do not have fully developed fine motor skills. Caution should be used with any tools - even scissors - and children must be closely supervised at all times.
This build is not suitable for children under the age of around nine. The bristlebots are not toys and should not be given to any child younger than this.

Step 2: Prepare Your Toothbrush

First, you need to prepare your toothbrush(es). You only need the head of the brush, you should be able to cut this away from the handle quickly and easily using the side cutters.

Once done, cut a strip of double-sided tape and stick this to the back of the brush.

Step 3: Add a Motor

Next, you need to add your motor. The motor is what will make your bristlebot move! Stick the motor right at one end of your brush. Make sure the wires are lifted clear of the sticky tape!

Depending on the motors that you use, you may need to expose more wire. Components designed for phones and pagers will only have tiny solder points, and will need more exposed wire to get a good connection with the battery. If so, gently strip a little more of the wire. If you are doing this as a community or group activity, you might want to do this in advance.

Step 4: Connect Your Battery...

Next, connect your battery. Use insulation tape to attach the two wires from the motor, one to each face of the battery. You will know when you have a good connection as the motor will spring into life! Try to get the tape snug across the battery to ensure that the wires don't slip - if one of the wires is loose, the bristlebot will keep stopping!

Once the wires are securely attached, you can stick the battery down on the top of the brush. Try not to stick it down too lopsided, as if the weight is shifted too far to one side or the other, your bristlebot will keep falling over. Good for a talk about centres of gravity, but not what we want for our bristlebots!

Step 5: Decorate Your Bristlebot!

Once you have attached the battery, your next job is to decorate your bristlebot! We chose to add antennae, googly eyes and a Coventry Makerspace sticker to finish ours off. Over the day, we saw some very outlandish (and very awesome) designs, with plenty of cyclops bots, eye stalks, and many-legged creepy crawlies! Have fun, but do remember that anything you add will potentially affect how your bristlebot moves.

Step 6: Next Stop: World Domination

One look at a bristlebot is enough to know that these little robots want to conquer the world! And that is just awesome, because everywhere they go, they will spread the word about how much fun making is and how anyone can be a robot engineer. We had so much fun teaching kids how to make them, and would recommend any Makerspace thinking about doing some community outreach with children to go for it! It is incredibly rewarding and a lot of fun!