Friday, April 22, 2011

Squishy Circuits - Playing with Electricity, Sort of

I first saw this idea on in this fabulous talk. The experiment sounded so fun, that I looked up AnnMarie Thomas's Squishy Circuits site, copied her recipes for the resistive and conductive playdoughs, picked up some "ingredients" at a local RadioShack and came up with an idea.

Actually, M came up with an idea. For some days he's been pretend-playing the episode of Megamind where Megamind lures Metro Man into a trap. Naturally, next thing he wanted to build was a trap for Metro Man. Perfect opportunity, isn't it?!

Being very ambitious, I wanted to build an activity that would combine pretend-play with math, science, and fine motor skills. Yeah, and have some sort of art element to it too.

And so the idea of a labyrinth was born. We started off by using a manila file folder that was laying around and converting it into the base of our labyrinth. I wanted M to help me draw it, but he wouldn't budge. So I drew it myself.

We then used regular playdough to build the low walls. M participated in this activity - pinched off little pieces of dough, rolled them into long noodles (he didn't like that part) and carefully laid them onto the drawn lines. This last part was particularly hard 'cause he had to make sure there were no gaps or cracks or the Metro Man would escape.

Next we painted the path bright red, sort of like a red carpet. Red is still M's favorite color, but it also fits here - looks like a red carpet (and Metro Man, with his good looks, fab hair and a knack for publicity seems like a Hollywood type).

Then we went to the kitchen to make special "electric" playdough. M helped me measure and mix the ingredients for the conductive (pink) dough, but then started experimenting on his own recipe. He eventually created something very goopy, but of beautiful pea-soup color, some fancy paint products call it "moss green" (I can never achieve this shade of green when I try, but he did it).

I then proceeded to show how a small LED light lights up when electrical current is applied to the playdough. M played with it a bit and discovered the importance of maintaining proper polarity. Finally, we built a small enclosure with the dough and put a plastic dome on top (since it's an old observatory. Told ya before - watch the movie for details). We then stuck a couple of LED lights into the dough above the entrance and connected the wires.

The trap was set and sure thing, Metro Man was caught... and caught again... and again... and then again only this time he was an astronaut.

M even wanted to play with this dough the next day, putting LEDs in, connecting the wires, and testing what happens when you stick an LED into the same piece of dough. We also built a playdough cake with a red LED candle and in the process found out that our resistive dough wasn't resistive enough and we were much better off with a piece of plastic.

We'll try this activity again in a few months. Hopefully by then I'll devise a more interesting setup that creates more opportunities for experimenting (and cook a more resistive dough).


  1. One suggestion for the "non-conductive" dough. The resistance will be much higher if you use deionized or distilled water. (If you use tap water, the resistance will be higher than for the salt dough, but much lower than what you would get using the deionized water!)

    Don't hesitate to call/email if you have any comments/suggestions/difficulties! We're always trying to update our Squishy Circuit website with new ideas!

  2. Yelena, this is awesome!! You are such a good mom! I'm not a science person at all, but I'm totally inspired to make some circuits with play dough.