Squishy Circuits

Posted by carl on Wed 24 August 2011

This was a project I saw on the web called Squishy Circuits. The idea is to make a dough like substance that will conduct electricity. Then you can mold it into interesting shapes and incorporate electrical components into the sculpture without putting wires inside. Connecting things does not require using a soldering iron - you just stick a wire into the dough.

[caption id="attachment_447" align="alignnone" width="300" caption="Light the Lights"]image0[/caption]

So the first step is to prepare the dough.

[caption id="attachment_446" align="alignnone" width="150" caption="The ingredients are ready."]image1[/caption]

We are making two kinds of dough here - conductive and non-conductive. The conductive dough will be used for making wires and the non-conductive dough will separate the conductive pieces so we don't have a short circuit. The conductive dough is colored with red food coloring and the non-conductive is left uncolored.

The conductive dough:

[caption id="attachment_448" align="alignnone" width="150" caption="Mixing the dough"]image2[/caption]

[caption id="attachment_453" align="alignnone" width="150" caption="Cooking it"]image3[/caption]

[caption id="attachment_454" align="alignnone" width="150" caption="Mad Scientist at work"]image4[/caption]

[caption id="attachment_455" align="alignnone" width="150" caption="Cooling off"]image5[/caption]

Next we mix up the non-conductive dough.

[caption id="attachment_456" align="alignnone" width="150" caption="non-conductive dough"]image6[/caption]

[caption id="attachment_457" align="alignnone" width="150" caption="Kneading it"]image7[/caption]

[caption id="attachment_458" align="alignnone" width="150" caption="Finished"]image8[/caption]

Now that we have the dough it is time to experiment. First check to see if the conductive dough really is.

[caption id="attachment_459" align="alignnone" width="150" caption="What is the resistance?"]image9[/caption]

The resistance was over 40K ohms which seems very high but lets see how it works. I used 4 AA batteries for power and two LEDs. The pink dough on one side is ground and the other is +6 volts.

[caption id="attachment_468" align="alignnone" width="150" caption="It works!!"]image10[/caption]

And it works! Yeah. The LEDs are pretty dim but the are glowing. Trying different sizes and shapes of dough and some different LEDs we did manage to get a little better results.

[caption id="attachment_447" align="alignnone" width="150" caption="Light the Lights"]image11[/caption]

After seeing our results our taste tester wanted to try something a little different - he built a battery out of the dough. To make a battery you several segments or "cells" hooked together in series using two different metals. Here it was steel staples and copper wires. And here it is.

[caption id="attachment_463" align="alignnone" width="200" caption="One Volt Battery"]image12[/caption]

So 6 cells make a 1V battery.

The next experiment will be to try a week later to see if the dough is still conductive. Also, it will be interesting to see if the conductivity wears out as it is used. And what happens if we let it dry out?

Experiments for another day.

Thanks to Jaimee and Bill for their help with this.