Squishy Circuits: Sculpting with Electricity!
Conductive dough, insulating dough, and the hidden world of circuits
Time: 45–60 minutes Complexity: Beginner Setup: Kitchen dough + basic electronics kit
Overview of Squishy Circuits 
Have you ever squeezed a ball of play dough and wished it could do something more than just hold a shape? What if that same dough could light up, buzz, or power a tiny motor? That is exactly what Squishy Circuits let you do. By mixing two very different batches of homemade dough — one that conducts electricity and one that blocks it — you can sculpt glowing creatures, buzzing monsters, and colorful characters that come alive with real current flowing through them.
This Squishy Circuits activity blends chemistry, electronics, and art into a single squishy package. You will learn why some materials let electricity flow freely while others act like a wall it cannot cross, and you will use that knowledge to build both series and parallel circuits — the same two wiring patterns used in every string of fairy lights, every household circuit, and every electronic gadget you own.
A squishy circuit creature: conductive dough for the body, insulating dough as a barrier, and glowing LED eyes.
Materials Required for Squishy Circuits
What you need:
- 2 cups flour (divided between two bowls)
- 1 cup table salt (for the conductive dough)
- 3 tablespoons sugar (for the insulating dough)
- 3 tablespoons cream of tartar (helps the dough stay soft, optional)
- 1.5 cups water, divided
- 3 tablespoons vegetable oil, divided
- Food coloring (a different color for each dough helps tell them apart)
- A 9-volt or 4×AA battery pack with connector wires, or several coin-cell LED holders
- 5mm LEDs (at least 2–3, plus a small buzzer if you have one)
- A saucepan and stove, or a microwave-safe bowl, for cooking the dough
- A mixing spoon and a plate or tray for sculpting
Step-by-Step Instructions
Four steps to create Squishy Circuits: mix the conductive dough, mix the insulating dough, sculpt with embedded LED legs, then connect the battery.
- Make the conductive dough: In a saucepan, combine 1 cup flour, 1 cup salt, 3 tbsp cream of tartar, 1 cup water, 1 tbsp oil, and food coloring. Cook on low heat, stirring constantly, until it forms a ball. Let it cool before handling.
- Make the insulating dough: In a separate bowl, mix 1 cup flour, 1/2 cup sugar, and slowly add deionized or distilled water until it forms a soft, non-sticky dough. Knead in a few drops of a different food coloring.
- Sculpt your base and body: Use the conductive dough to build the main body of your creature or shape — this is the part that will carry electricity.
- Add an insulating barrier: Anywhere you do NOT want electricity to jump between two conductive parts, place a thin layer of insulating dough as a wall or separator — for example, between the two legs of an LED.
- Embed the LEDs: Gently push the two legs of an LED into two separate blobs of conductive dough, making sure the legs do not touch each other directly (that would short-circuit the LED).
- Connect the battery pack: Push the red (positive) wire into one conductive dough blob and the black (negative) wire into another. If the LED does not light up, try flipping it around — LEDs only work in one direction!
- Experiment with series and parallel wiring: Try connecting a second LED using only one shared blob of dough (series), then try giving each LED its own direct path to the battery (parallel). Compare the brightness.
Pro Tip
- For the best Squishy Circuits results, keep your conductive dough soft and slightly moist for better electrical conductivity.
- If the conductive dough dries out after a day or two, don’t worry—this is completely normal because the salt in the dough naturally draws out moisture.
- Knead in a few drops of water until the dough becomes soft and smooth again to restore its conductivity.
- Store both the conductive and insulating dough in separate airtight containers or zip-lock bags to prevent them from drying out.
- Always keep the conductive dough and insulating dough separate while building Squishy Circuits to avoid accidental short circuits.
- Before connecting the battery, check that the LED legs are inserted into separate pieces of conductive dough and are not touching each other directly. This helps your Squishy Circuits project work reliably every time.
The Science Behind the Squishy Circuits
The science behind Squishy Circuits begins when tiny charged particles called electrons move through a material. Some materials, called conductors, have electrons that move easily from atom to atom — metals like copper are excellent conductors, which is why they are used in wires. Other materials, called insulators, hold their electrons tightly in place, so current cannot pass through them at all.
Your conductive dough works because of the salt. When salt (sodium chloride) dissolves in water, it splits into charged particles called ions — sodium ions and chloride ions. These ions are free to drift through the wet dough, carrying electric charge along with them, just like electrons moving through a copper wire. Your insulating dough, on the other hand, uses sugar instead of salt. Sugar dissolves in water too, but it does not split into charged ions, so there is nothing available to carry current. That is why the sugar dough behaves like a solid wall against electricity, even though it looks and feels almost identical to the conductive dough.
In Squishy Circuits, series circuits share one path and split the current, while parallel circuits give each LED its own path for full brightness.
When you build a series circuit, both LEDs sit along a single shared path, so the same current has to squeeze through both of them one after another. This usually makes each LED noticeably dimmer, and if one LED is removed or a connection breaks, the whole circuit stops working — much like old-style Christmas lights where one bad bulb could turn off an entire string. In a parallel circuit, each LED gets its own separate branch running directly back to the battery. Each branch receives a fuller share of the current, so the LEDs shine brighter, and if one LED fails, the others keep glowing happily on their own branch.
Expected Results for Squishy Circuits
Once your circuit is wired correctly, the LED embedded in the conductive dough should light up within a second or two of connecting the battery. If you built a series circuit with two LEDs, you should notice they glow slightly dimmer than a single LED would on its own. If you built a parallel circuit instead, both LEDs should glow at close to full brightness, almost as bright as if each had its own private battery.
Variations to try: a single glow-worm, a buzzer creature, and a rainbow multi-LED sculpture.
Fun Squishy Circuits variations to try:
- Swap the LED for a small buzzer and make a creature that beeps instead of glows
- Build a whole family of dough creatures and connect them all to one shared battery pack
- Use a multimeter (if you have one) to measure the resistance of your conductive dough versus your insulating dough
- Challenge: build a circuit with three LEDs in parallel and see if you can still make all three glow brightly
Conclusion
There is something genuinely magical about watching a lump of dough you mixed yourself light up in your hands. It is easy to think of electricity as something locked away inside plastic-coated wires and printed circuit boards, but Squishy Circuits prove that the same physics is available in a mixing bowl. By building both series and parallel circuits with your own hands, you have felt the difference between the two most fundamental ways electrical engineers connect components in every device around you.
The next time you plug in a strand of holiday lights or notice that your phone charger has multiple ports, you will understand a little more about the invisible pathways carrying electricity to where it needs to go.
What Did You Learn?
After completing this Squishy Circuits activity, you learned how electricity flows through conductors, how insulators block current, and how real circuits work.
Conductors vs insulators. Salt dissolved in water creates ions that carry electric charge, while sugar dough has no charged particles to move, so it blocks current.
Series circuits share current. When components sit on one shared path, the same current must pass through each of them, often dimming the result.
Parallel circuits share the source. When each component gets its own path back to the battery, each one can receive a fuller, brighter share of current.
LEDs have a direction. Current can only flow through an LED one way, so flipping its legs is often the fix when it refuses to light up.
Everyday materials hide real physics. Flour, salt, sugar, and water can demonstrate the same electrical principles used in professional circuit design.
Frequently Asked Questions
1.Why does my LED not light up at all?
Check that the LED is facing the right way — the longer leg should connect toward the positive (red) wire. Also make sure the two dough blobs holding each leg are not touching each other, since that would create a short circuit that bypasses the LED entirely.
2. Can I use table salt substitutes like potassium chloride?
Yes. Any salt that dissolves into ions in water will work as a conductor, though regular table salt is the cheapest and most reliable option for this activity.
3. Is squishy circuit dough safe to touch?
Yes, both doughs are non-toxic and safe to handle, similar to regular homemade play dough. However, the batteries and small LED components should be kept away from very young children who might put them in their mouths.
4. Who invented Squishy Circuits?
Squishy Circuits was developed by AnnMarie Thomas and her students at the University of St. Thomas as an accessible way to teach basic electronics to young children using materials found in any kitchen.
