This experiment can be found in my award-winning book, Pop Sizzle Boom! 101 Experiments for the Mad Scientist in Every Kid!
One of our favorite parts of the holiday season involved driving around to find extravagant light displays. We pack cocoa, sing carols, and find new neighborhoods and parks to walk through as we delight in the dazzling, glittering lights around us! We wanted to find a way to combine our love for Christmas lights with our love for science, in a way that would be safe and fun for both my 12-year-old daughter and my 3-year-old toddler! We found our answer with every kid’s favorite toy… playdough!
With this experiment, you can create your own electrical circuits with the safety of playdough, right in your living room! By combining chemistry, physics, and art, you can explore sculpture and electricity, with store-bought Playdoh, or by making your own conductive playdough!
In this post, you’ll find instructions on how to set up your playdough sculptures, recipes for conductive playdough (you can also use store-bought Playdoh) and insulated dough, and some troubleshooting tips!
Supercharged Creativity With Playdough Electronics!
AA battery pack with wires (4 pack battery holder)
4 AA batteries
Spade terminals (18-22 gauge)
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* Recipes for DIY playdough and DIY insulated dough can be found at the end of this post. You can use modeling clay as insulated dough (dough that isn’t conductive and will act as a wall for your electricity so you don’t short out your circuit!), but this can be stiff and difficult to work with at times. The insulated dough can be used with cookie cutters or with your hands to create large and easily moldable barriers to create fun and creative works of electric art!
Remove the batteries from the battery pack. If the wires attached to your battery pack do not have a small amount of exposed wire at each end, use your wire strippers to cut and peel away a small part of the insulated coating.
Take the exposed end of the wire and run it through the spade terminal, until it is inside the small hollow groove near the base of the fork. Use your crimpers to tightly crimp the groove onto the wires.
Take two small pieces of conductive Playdoh, and roll them into a log shape. Stick the spade terminals into each one, so that you have a red wire sticking into one piece of dough, and the black wire into the other.
Safety Tip: Never touch the wires to the batteries, and try to keep them separated from each other. Never touch the posts of your LEDs to your battery terminals!
LIGHTING YOUR CIRCUITS
Look closely at the posts of the LED light. One post is slightly longer than the other. This longer end goes into the positive dough, the piece with the red wire sticking through it. The other end goes in the negative.
Place your separate dough pieces on a flat surface, ½” apart. Then, take out one of your LEDs, and place each leg into the dough (remember, the long end goes in the positive dough, the short end into the negative)!
Build a bridge of LEDs with your conductive Playdough! How many LEDs can you fit onto your conductive dough?
Push the two pieces of dough together. What happens to the light when the dough is touching?
Take a small piece of your modeling clay or insulated dough, and roll it into a small log shape, the same length as your Playdough dough.
Place it in the middle of the pieces, and then push them together. Now, the conductive Playdough is closer together, but not touching! You’ve been a wall of insulation between your dough! With everything touching, will your LEDs light up?
You can use your playdough and modeling clay to build all kinds of fun and creative electric sculptures! You just need to make sure that your two playdough wires aren’t touching each other. Make sure the modeling clay is between your two layers of playdough so you can keep your electric circuit going! We’ve used our electric playdough circuits through our summer camps and science programs, and the kids have come up with all kinds of creative designs!
Here are some examples of what kids have done with our electric Playdough sculptures:
One of the easiest designs to make is a beautiful butterfly! This is done with two large pieces of playdough, with the body of the butterfly being made with insulated dough or modeling clay.
Another design kids love to make is lighting up their own playdough burgers!
Some kids have designed their own electric cars with their playdough circuits:
And of course, kids also loved creating their own electric emojis!
Making playdough electronics easy for the little ones!
Finally, we took our playdough electronics experiments to a preschool storytime event at our local library. With kids ages 3-6, we needed to find a way to make this toddler-friendly, and easy for little hands to work with. We found cookie cutters helped make this super easy and fun for little hands! We also found that the insulated dough was much easier for little kids to work with than the stiff modeling clay. Use the cookie cutters to make two playdough shapes and one insulated dough shape. Then make a sandwich with two pieces of playdough on the outside and the insulated dough in the middle. The kids loved making snowmen, gingerbread people, and candy canes light up like Christmas trees!
When you lit your lights with your battery and dough, you created a closed circuit. This is when electricity has a clear path from its power source (the battery pack) through a conductor (your dough), and into a device that uses that power (the light bulb!). If you were to remove one of the pegs of the light bulb from the dough, the light would turn off, the circuit would be open. Electricity works effectively to power a variety of objects through closed circuits!
How does the dough work to conduct this electricity? Your conductive dough is a conductor, which simply means that it easily allows electricity to run through it. The salt and the tap water, both contain ions, which give the dough a negative charge, which easily allows the electrons from the battery (which is where the electricity comes from!) to flow through your light source
When you placed your conductive dough slightly apart, and bridged the gap with your lights, your lights turned on with the power of electricity! However, when you touched the dough together, the lights turned off, because you created a short circuit! This is when a path of electricity has little to no resistance, so the charges meet, resulting in an excess of heat and energy which can burn out or damage your bulbs.
Your insulated dough, however, has a high resistance, which builds a wall between the electrons in the battery, and your light source. Instead of using salt and tap water, which has a lot of electrically charged ions, you used sugar and distilled water, which has a high resistance to electrical flow. You can use your insulated dough to block the current from your conductive dough when they’re touching. This allows you to build smaller and more intricate shapes with your dough, while also maintaining your closed circuit!
Conductive and Insulated Dough Recipes!
This is your basic playdough recipe. Its super easy and takes about ten minutes to make!
1 cup all-purpose flour
1/3 cup salt
2 tsp cream of tartar
1 cup water
1 tbsp vegetable oil
Add dry ingredients to a medium-sized pot, then stir until they’re thoroughly combined. Add the wet ingredients, and stir again until everything is mixed. Make sure to break any lumps down so the flour is thoroughly combined with the oil and water.
Cook over medium-low heat, stirring continuously. Once the dough starts getting a little thick and lumpy, add about ten drops of food coloring to create a colored dough. Stir to combine until your dough is one solid color.
Once the dough starts to pull away from the sides of the pot and stick to your spoon, its ready to take out! Put it in a bowl to let it cool. Once its cool to the touch, you can add 1 tbsp of oil and knead the dough until it is smooth and pliable. Then you can put it in a plastic bag or airtight Tupperware container to store for future use!
This is similar to a playdough recipe, but it uses sugar instead of salt, and requires no cooking.
1 cup flour
1/2 cup sugar
3 tbsp vegetable oil
1/2 cup distilled water
Combine your dry ingredients into a medium mixing bowl. Then, add the oil and stir until the dough gets a little lumpy. Add small splashes of distilled water until the flour has absorbed the water and reached a dough like consistency. I’ve found that it takes about 1/4 cup of distilled water to reach that point.
Add a few pinches of flour to knead into the dough until it no longer sticks to your hands. Once it has reached a consistency similar to bread dough (doesn’t stick to your hands, you can roll it into a ball), you can place it in a plastic bag or airtight Tupperware container for storage.
Trouble Shooting Tips
Are your lights not lighting up? Try these tips!
1. Double check to make absolutely certain that your two pieces of playdough are not touching each other. Make sure there is a good amount of modeling clay or insulated dough between your playdough pieces. Remember, if your playdough wires touch, you’ll short the circuit and the lights won’t work!
2. Take your LEDs out and double check that the long end is in the positive wire, and the short end is in the negative. Electricity flows in one direction in these lights, so if they’re placed in the wrong Playdough wires, they won’t work!
3. Take out the battery wires and check to make sure there’s enough playdough to get a good connection. If your pieces of playdough are too thin, the wires may not have enough surface area of conductivity to push the electricity through. Try thickening up your pieces of playdough and then putting your wires back in.
4. After about an hour of usage, the salt in the playdough will begin to corrode the surface of the spade terminals. To replace them, simply use your wire cutters to cut off the wire right at the end of the terminal. Use the strippers to strip a piece of rubber, exposing a small amount of wire. Then, grab a new terminal and crimp it on! They’ll be as good as new so you can keep experimenting with your playdough sculptures!