# Squishy circuits

Squishy Circuits is a project to teach kids about electricity and electronics by having them form circuits out of Play-Doh-like dough — with two varieties, conductive and insulating.

Squishy Circuits were developed at the University of St. Thomas by undergraduate Samuel Johnson and Dr. AnnMarie Thomas. The purpose of their development is to facilitate electronics education to younger students. Research is being done to determine the most effective implementation of this learning tool in a middle school science curriculum. Our hope is that through the use of this tool, students will better understand electronics concepts, become more interested.

The simplest circuit to build consists of an LED, battery pack, and three small “tubes” of dough (Two conductive and one insulating). To build this circuit, separate the two conductive tubes with a tube of insulating dough. Now, insert each of the battery pack wires into a separate tube of conductive dough. Do the same with the leads from the LED but be sure that the short end of the LED is inserted into the same tube that holds the black, or negative, battery pack wire.

### 5 Responses to Squishy circuits

1. StayatHomeElectronics on said:

That’s great that they also give you the recipes for the conductive and nonconductive doughs!

2. NeuroPulse on said:

Can you make a transistor with this?

If not, is it possible to make doughs that can make a transistor?

• rawley69 on said:

These are basically playdough wires. Transistors are a semi-conductor made with silicon that is doped to have either an abundance of positive or negative charge carriers.

• Robert Jones on said:

Was that a “yes” or a “no”? I suspect that “semiconductor” squishy material CAN be made by reducing the amount of salt in some conductive dough, or by using a different salt that has lower solubility or larger ions that have limited mobility compared to the Na+ and Cl- ions. Ammonium acetate is a neutral salt that might work since these ions are relatively larger. Experimenters??

3. What kind of LED is required for this project? Not all LED lights are created equal and some need much more current than others to light up. So for the project to work with a 6-9V battery pack, what is the mA requirement for the LED?