Helpful Links:

https://www.youtube.com/watch?v=60AU2Pq-X9g

https://www.instructables.com/id/Use-a-DIY-Pressure-Plate-Switch-to-Automate-Your-H/

https://learnlearn.uk/microbit/topics/microbit-input-from-external-switches/

https://www.stem.org.uk/resources/elibrary/resource/425048/understanding-electronic-principles

The zombies are coming! Fortunately, you've found a safe place to hide and enough provisions to keep you and your team alive for the next few weeks. But in order to stay safe, you'll need to know if any zombies are prowling around outside your base.

Your task:

Plan and build a pressure pad sensor that warns you when zombies are nearby.

The first thing you need to do is build a pressure pad. A pressure pad is a switch that closes when it is stepped on. It is made of three layers: a top and bottom layer that both contains conductive material, and a space in between these layers that separates them. When stepped on, the top and bottom layers touch, completing a circuit.

1. Draw the circuit that your pressure pad will be part of. Remember, the circuit will only be complete when someone (or something) is stepping on the pressure pad. Your circuit needs to include a light or buzzer to tell you when there’s a zombie nearby, and also a source of power.

2. Choose which materials you’ll use for your top, bottom and middle layers. What properties will each one need? You may need to combine different materials in each layer to get the properties you want.

3. Think about how you’ll keep the conductive layers apart, but allow them to touch when a zombie steps on your pad. Include a way to connect your pressure pad to the rest of your warning circuit.

4. Assemble your pad and connect it to your warning circuit.

5. Test your pad: will it keep you safe?

6. Consider how you could improve your design and make it more effective