Squishy Circuits 2: Rise of the Thermocromatic Paint

After our first foray into squishy circuits last week, a few of us moved on to new squishy experiments with mixing in thermochromic paint, that stuff that changes color when heated and cooled. We were inspired by the ideas and materials that Nicole brought back from her visit to the high-low tech research group at the MIT media lab to see some of the amazing work they’ve done on a resource site called kit-of-no-parts. The conductive play-dough was made using the same recipe but we added some of the powdered color changing paint to the mix. The first paint that we tried became clear (or white) when heated and turned a pinkish color when cooled. By adding food coloring, we changed the base color so it went from yellow when hot to a dark pinkish-orange when cooled.

We wanted to run a current through the dough to heat it up and create designs like we saw on the kit-of no parts website here, but it didn’t seem to heat up enough to affect the color of the dough. It was more fun to warm the dough by rolling it around in the palm of our hands and then cool it off on a soda can straight from the fridge and watch the patterns as the color seeped in at different speeds depending on the thickness of the play-dough.

The cold soda can also worked as a great rolling pin that cooled the clay as it flattened the lumps into pancake shaped disks. We’ll have to try other ways of heating and cooling the clay to observe more complicated or controllable patterns in the substance, but once again it was immensely satisfying to see a somewhat esoteric concept like electricity or thermodynamics demonstrated with perhaps the most approachable material of all.