|This is a simple version of the circuit.|
Normally I post activities that are easy to do at home and don't require a lot of extra equipment. But squishy circuits are tons of fun. I had to post this.
|This is what learning looks like when students are focused on the task. Nothing beats hands-on learning.|
Materials: Flour, water, distilled water, salt, cream of tartar, vegetable oil, sugar, food colour, LED lights, a battery holder that takes at least 4 AA batteries (AAA, C, or D would work too), four AA batteries, bowls, a pot, measuring spoons, patience
Batch A - Play dough that conducts electricity
Step 1 Mix together 355 ml (1 ½ cups) of flour, 250 ml (1 cup) water, 60 ml (¼ cup) salt, 15 ml (1 tbsp) vegetable oil, some food colour, and 45 ml (3 tbsp) cream of tartar, in a medium size pot.
Step 2 Heat it at medium heat and keep stirring it until it is a ball in the middle of the pot. Carefully remove the VERY HOT dough and let it cool for a few minutes.
Step 3 After it has cooled, knead it with a bit more flour so it is not too sticky. Set aside.
Batch B - Play dough that does not conduct electricity
Step 1 In a bowl, mix together 355 ml (1 ½ cups) of flour, 120 ml (½ cup) of sugar, 45 ml (3 tbsp) of vegetable oil, 125 ml (½ cup) of distilled water, some food colour (*a different colour than batch A)
Step 2 Keep mixing it until it is like bread dough and it is not too sticky. Knead this batch adding flour until it is not too sticky. Set aside.
Make the Circuit
Step 1 Put the batteries in the battery holder. Make sure the battery holder has two wires coming out that have exposed metal wire.
Step 2 Make an animal or any other design with the playdough. There should be two pieces of conductive play dough separated by a piece of insulating play dough. Bend the legs of an LED so that it goes in both pieces of conductive play dough.
Step 3 Now push the two wires into the two pieces of conductive play dough so the metal wire is buried in each piece. If the light doesn't work, you may need to switch the wires from the battery pack to the opposite sides (electricity can only flow in one direction through an LED).
The Science The conductive play dough (Batch A) has ingredients that allow electrons to pass through it (salt and water). The insulating play dough (Batch B) does not allow electrons to pass through it. The sugar helps stop the electrons. A circuit is simply a path for electrons to follow. The LED releases energy in the form of photons (light). Basically, your circuit is a path that has a lamp out of which photons are released. The play dough that conducts electricity acts as a wire.
|This one wasn't finished yet when I took this picture, but I just had to post it anyway.|