Squishable Circuits

This circuit works by connecting components not through wires, but by dough!

Overall, there are two types of dough-- a conductive, as well as insulative one. When using the two together, it can form the basis for our circuit.

For the conductive dough, it uses quite a lot of salt, which is a key component. This is because once we heat up the dough, salt (NaCl), which in its original state is neutral, dissolves in the water. However, by mixing it, the salt dissociates into positively charged sodium ions (Na⁺) and negatively charged chloride ions (Cl⁻). These free-moving ions in the dough allow electricity to flow through it, similar to how metals conduct electricity through free electrons.

Similarly, by using lemon juice, we also are able to increase the conductivity. This is due to citric acid, which releases H+ ions.

On the other hand, the insulative dough uses a lot of sugar, which is especially important because it doesn't contain salt or other electrolytes, so there are no free ions available to carry an electric charge.

We also use distilled water, which is already purified from the dissolved salts and minerals that other waters may have. Because of this, there aren't any free ions available to conduct electricity.

Have fun!!

1. conductive dough (see Instructable for how to make your own)
2. insulating dough (see Instructable for how to make your own)
3. 2x LEDs
4. 1x 120 ohm resistor
5. 3x male-male jumper wires
6. 2x alligator clips
7. 4x 1.5v batteries + battery holders

Create the scene you will later insert your components into, using both the conductive and insulating dough (make sure you are able to differentiate between the two-- in mine, the colorless/yellowish brown dough is what I used for insulating, while the colorful dough is conductive).

Now, you can create a circuit, with the dough acting as connectors between your components!

When inserting your components, it is important to make sure that each leg is separated by either insulative dough, or a dough not connected to it. As you can see, for the butterfly (as well as the mushroom), the red LED's legs are separated by a line of insulative dough. This prevents a short circuit, so the current doesn't just 'skip' to the LED. For the yellow LED, the legs are physically on different piles of dough (the air can be thought of as the insulator here).

When connecting your LEDs, also make sure that the positive (longer) leg connects to the positive end of the battery, and the negative is connected to the negative end. In my model, the positive end is represented by the orange wire, and the negative by the yellow.

Now, simply connect your jumper wires to the alligator clips and battery. Your circuit should light up!

Feel free to experiment with different types/amounts of LEDs, components, and designs. The possibilities are endless!