You will need
- Double sided sticky tape
- PVA glue
- A4 card
- Coloured pens or pencils
- Craft materials (for example, tissue paper, pipe cleaners, stickers)
- Scrap card
- Tape measure
- 3V coin battery (with circuit board pins works best)
- Mini vibration motor
- A small brush, like the head from a large toothbrush or small nail brush
- Wire strippers
- Googly eyes
- File/sandpaper, as needed
Before you begin
- Have everyone bring in any spare cardboard, such as a cereal box, shoebox, tissue-box or loo-roll tube.
- A ‘vibration motor’ is just a normal motor with a weight on its axle. The weight offsets the axle when it spins, making it unstable. The movement of the weight caused by the spinning of the axle makes the motor move up and down. This is what causes our mobile phones and other devices to vibrate. As an extension, you and your group could make your own vibration motor from a normal motor.
- As this circuit is powered by a 3V (volt) battery, the voltage of the circuit is three volts. Everyone should add this to their diagram. Check and make sure your motors require 3V or less, or they might not work properly.
- If cutting off brush heads from toothbrushes, check that this doesn’t leave a sharp edge. You may need to file down any broken edges before using the brush head.
Run the activity
- Give out pencils and paper and have everyone copy out the circuit diagram (above). Remind everyone to label the voltage of the circuit (3V).
- Everyone should then collect all the components they need and lay them out on their diagram, so that it’s clear what goes where. A paperclip will be used as the switch. Each person needs two paperclips.
- See that everyone understands how the circuit works.
- Start by cutting down the wires from the motor, so that they’re about 4cm long. You might need a ruler. Then, with wire-strippers, remove 1-2cm of the ‘insulation’ (the plastic wire coating) from the end of each wire. This needs to be done with care, as the wires are very delicate.
- Attach a paperclip to each motor wire. Loop the wire through each one and fold it back on itself.
- Now, make a battery holder by cutting out a rectangle of card the same height as your 3V battery, and a bit more than three times the width of it. Fold the card into a pocket, like a wallet, which the battery can slide into. Inside, the battery should have two layers of card on one side and one layer on the other, so that it’s snug as a brush bug in a rug! With glue, stick the card together so that it holds this shape and remove the battery.
- With double-sided foam tape, stick the motor to the top of your cardboard pocket. Check that there’s nothing stopping the motor from working. Then, slide the battery back into the pocket.
- Take one of the paperclips attached to either wire, and attach it to the single-layered side of the cardboard pocket. The other end of the paperclip should still be attached to the wire.
- Stick the single-layered side of the cardboard pocket to the flat side of the brush head.
- Now, check that it works! Attach the second paperclip to the inside fold of the cardboard pocket, so that it touches the battery terminal. The motor should come to life. Turn the brush bug on and off by clipping and unclipping the top paperclip. Place it brush side down and watch how it moves.
- Switch your bug off. Add some decoration to make it look more like a bug. Pipe-cleaner antennae and googly-eyes are recommended! Try to make your brush bug unique.
- Use some cardboard to make a course that the brush bugs move well on. Loo-roll tubes, shoeboxes and tissue boxes could all be used. When the course is ready, everyone should line up their personalised brush bugs for a race!
- Test out your bugs on some different surfaces to see how they go. Make a note of which surfaces they prefer, and which are no-go zones. See if you can find a use for the brush bug, like creating a game for the bugs to play in teams, like hockey, or by attaching small felt pens to them and creating brush bug art.
Making brush bugs required us to use vibration motors. These have lots of applications in modern tech, from video game controllers to mobile phones. It’s another way for technology to send us an alert. Which of our senses might detect a vibration? Can you think of other devices that do different things to appeal to different senses? Why might this be useful? Could you come up with any ways to modify a device, like a fire alarm, to make it work for someone who is deaf? It could have a wristband that vibrates alongside the alarm side, to alert the user.
Supervise young people appropriately when they’re using scissors. Store all sharp objects securely, out of the reach of young people
- Glue and solvents
Supervise young people appropriately when they’re using glue and solvent products. Make sure there’s plenty of ventilation. Be aware of any medical conditions which could be affected by glue or solvent use and make adjustments as needed.
- Sharp objects
Teach young people how to use sharp objects safely. Supervise them appropriately throughout. Store all sharp objects securely, out of the reach of young people.
Supervise young people, and only do science activities that are advised and age appropriate for your section. Test activities first, to make sure you’re confident you can lead them safely. Use protective clothing where necessary.
- Manufacturer’s guidelines
All vehicles will be different so always follow the manufacturer’s guidelines.
Before completing this activity make sure you have suitable personal protective equipment (PPE). This could include eye or ear protection, gloves, and anything else you need to protect yourself. You’ll know what you need as a result of completing the risk assessment for the activity.
Soldering irons produce a lot of heat. Never touch the tip of the soldering iron on anything other than the things you’re soldering and use tweezers or clamps to hold things in place. Never solder near flammable gases or liquids or combustible materials such as wood, textiles, or paper. Make sure there’s a fire extinguisher and a first aid kit (with items to treat burns) nearby.
Wear non-flammable clothing, gloves, safety goggles, and closed-toe shoes. Cover your arms and legs to prevent burns and remove loose clothing (such as scarves).
Work in a well-ventilated area to avoid inhaling fumes and keep food and drink away from the working area to avoid contamination.
Remove any equipment you’re working on from the power source before you begin. Never assume the power circuit’s off – test it with a voltmeter (and then test it again to be sure).
Only connect power to a circuit once you’ve finished working on it and have checked your work. Make sure your circuit isn’t overloaded, and return any covers you’ve removed.
Make sure that all electronics equipment is properly grounded. Use the right electronics tools, and always replace damaged equipment (for example, replace cables rather than repairing them with insulating tape). Always have safety equipment including a fire extinguisher, basic first aid kit, and mobile phone nearby.