Experiment with safe and easy electrical circuits you make yourself. Use everyday kitchen ingredients to cook up some homemade dough that you can mould to serve as wires in a circuit. This activity explores two types of dough “wires.” The first conductive dough will allow electricity to pass through it, and the second insulating dough will stop electricity in its path. Using the two together, you’ll create a circuit to power an LED (light-emitting diode).
9V battery and holder with wire leads (see photo)
one LED bulb (available at electronic supply shops)
cookie cutters (optional)
Making Conductive Dough
250 ml flour
60 ml salt
5 ml vegetable oil
25 ml baking powder
250 ml water
Mix the flour, salt and baking powder together in the saucepan.
Slowly mix in the water, vegetable oil and food colouring.
With the help of an adult, bring the mixture to a boil over medium heat, stirring constantly.
When the mixture begins to form a ball, remove it from the heat and place it on a lightly floured surface. Let it cool for a few minutes before touching it.
Once cooled, knead the dough with your hands. If it is too soft, add more flour; if it is too hard, add more water.
You can keep your dough for up to two weeks in a plastic bag — be sure to label it as conductive.
Creating a Simple Circuit
Use only the conductive dough to create a simple circuit. The electricity must flow from the battery to the LED, then back to the battery again. Using two pieces of conductive dough, insert one battery-pack wire into each piece. Next, insert each end of the LED wires further down and watch it light up as electricity flows through your circuit. If the LED does not light up at first, switch the wire ends of the bulb from one piece of dough to the other.
Making Insulating Dough
Try making this insulating dough in a different colour, then add it to your circuit to make new paths of electricity. Remember when you’re designing that the insulating dough will stop the flow of electricity, so use the conductive dough to keep the electricity flowing.
250 ml flour
125 ml sugar
15 ml vegetable oil
125 ml water
Mix the flour, sugar and vegetable oil together in a bowl.
Slowly stir the water into the mixture.
Transfer the lumpy mixture onto a floured surface and knead the dough with your hands, adding the remaining flour until the dough reaches an elastic consistency.
You can keep your dough for up to two weeks in a plastic bag — be sure to label it as insulating.
Now, with the combination of both conductive and insulating doughs, you can let your imagination run wild as you design your own circuits. Braid your dough into a woven circuit jumble, or use cookie cutters to make beautifully shaped circuits. Discover how electricity travels from the battery to your light by placing any number of LED bulbs in different places along your circuit.
Electricity is produced by the movement of tiny negatively charged particles called electrons, shown here as . Flowing electrons produce what we call a current through a conductive material such as electrical wires or our conductive dough. The electron current can only travel if it can complete a loop or circuit back to the battery, as in the diagram below.
In the above diagram, the electron current flows (1) out of the battery, then (2) through the conductive wire, (3) through the LED to light it up, (4) through the second conductive wire, then finally (5) back to the battery.