Conductive Playdough Circuits

Circuits for Kids

Electricity doesn’t always travel through wires—it can flow through playdough, too! Kids can create a squishy playdough circuit with a simple homemade recipe and watch LEDs light up, making science and engineering exciting and interactive.

Grade Level Recommendation: Grades 2-5

💡Find more electrical engineering activities [here]!

Ingredients for Conductive Playdough:

• 1 cup water
• 1 cup all-purpose flour
• 1/4 cup salt
• 3 tbsp cream of tartar (or 9 tbsp lemon juice as a substitute)
• 1 tbsp vegetable oil
• Food coloring (optional, for fun colors)

💡🛑 Learn more about how to make a simple circuit [here] without playdough. Then advance to parallel circuit and series circuit projects!

Materials for Testing Playdough Circuits:

• 9V battery
• LED lights
• Alligator clip wires

How to Make Conductive Playdough

💡You’ll also want to make a batch of our Insulating Playdough [here].

Mix the Ingredients

• Combine water, flour, salt, cream of tartar, oil, and food coloring in a medium saucepan.

Cook the Mixture

• Place the pan over medium heat.
• Stir constantly until the mixture thickens into a doughy texture.
• Remove from heat once it forms a playdough consistency.

Cool and Knead

• Let the dough cool for a few minutes.
• Knead it until it’s smooth and pliable.

Store Properly

• Place the playdough in an airtight container or plastic bag to keep it fresh.

🛑 Adult supervision and assistance are recommended when exploring circuits and electricity.

Testing the Conductive Playdough:

1. Roll two pieces of playdough into small balls.
2. Insert the two prongs of an LED light into separate balls of playdough.
3. Connect one alligator clip wire from the positive terminal of a 9V battery to one playdough ball.
4. Connect another wire from the negative terminal to the other ball.
5. Watch the LED light up as electricity flows through the conductive playdough!

How Conductive Playdough Works:

• The salt in the playdough acts as an electrolyte, allowing electricity to flow through the material.
• The LED completes the circuit, lighting up when electrons pass through the playdough.

Electricity needs a pathway to travel, and materials that allow electricity to flow easily are called conductors. The salt in the playdough dissolves into tiny charged particles called ions when mixed with water. These ions allow electricity to flow through the playdough, completing the circuit.

When you connect the positive terminal of the battery to one piece of playdough and the negative terminal to another, the electricity travels through the ions in the dough. The LED light is placed in the middle of this circuit, and when electricity passes through it, the LED lights up.

If you place a piece of insulating playdough between two conductive pieces, the circuit will break because sugar does not create free ions for electricity to pass through.

This experiment is a great way to see how circuits can be created with everyday materials and how different materials affect the flow of electricity.

STEM Extensions:

• Creative Circuits: Challenge kids to build playdough sculptures with working LED lights.
• Compare Conductors and Insulators: Make insulating playdough using sugar instead of salt and observe the difference in conductivity. (coming soon)
• Circuit Designs: Encourage kids to design shapes and patterns that incorporate LEDs.
• Multicolored Circuits: Create a circuit with different colored LEDs to form a glowing design.
• Playdough Robots: Build small playdough robots with LED eyes that light up.

Conductive Playdough Tips and Tricks:

• Add more salt for better conductivity.
• Store playdough in an airtight container to prevent it from drying out.
• Use different colored LEDs to make your projects more vibrant!

Simple Circuits for Kids: Quick Activity List