Did you know ordinary shop bought play dough conducts electricity? This makes it a great alternative to fiddly wires and a wonderful, hands-on low cost way to learn about electricity and circuits. All you need is play dough, a battery pack, wires and some LEDs.
Conductive play dough contains salt which when dissolved in water conducts electricity. Insulating dough contains sugar, which does not conduct electricity. Insulating dough is
only needed for more adventurous circuits and needs to be home made, however, regular play dough provides plenty of learning opportunities if you want to keep it simple.
- Conductive play dough – shop bought or make your own
- Insulating play dough
- Light emitted diodes (LEDs )
- Buzzer – optional
- AA Batteries – 4 work best
- Battery holders and connectors or a battery pack
- To construct a simple electrical circuit, identify and name basic parts.
- Understand that LEDs only work one way around. The long leg must be towards the positive end of the battery.
- Recognise that the circuit must be complete for the LED to light
- Understand that electricity always takes the easiest path back to the battery.
- Understand the difference between a series and parallel circuit.
If making your own play dough, any play dough recipe which uses salt will work.
To make insulating play dough replace the salt with sugar.
To make a simple circuit use 2 balls of play dough and connect the circuit as shown. Remember the long leg of the LED must be in the play dough connected to the positive end of the battery.
Push the two sections of play dough containing the LED legs together. The LED should turn off. This is because electricity takes the easiest path so goes through the play dough not the LED.
LEDs in series are in a row, you should find the more LEDs the dimmer each of them are.
In a parallel circuit electricity flows through each LED separately so all LEDs should be of equal brightness.
Make a switch
Try using the play dough to create a switch.
Add a buzzer
Connect a buzzer to your circuit instead of LEDs.
Make a play dough model
Try creating a play dough model with LEDs. You might need to use insulating play dough to separate the connections.
Remember never connect an LED directly to the battery as the voltage will be too high. In your play dough circuit the play dough acts as a resistor reducing the voltage that reaches the LED.