Around here we’re very interested in finding new ways to make electronics more approachable. While we think it is very important to have the opportunity to play with the tools of the trade, placing a scalding hot soldering iron into a child’s hand can be a bit reckless and we don’t want to see you end up on the evening news. So, how do you make basic electronic circuits exciting for kids (and, let’s face it, everyone)? Well, you make it squishy.
Squishy Circuits are the brainchild of AnnMarie Thomas, a professor at the University of St. Thomas and director of the UST Design Lab. AnnMarie leads a team of students looking at both the playful side of engineering (squishy circuits for students, the science of circus, toy design) and ways to use engineering design to help others (projects in technology design for older adults). You can learn more about AnnMarie at her website.
Drawing inspiration from Leah Buechley’s LilyPad collection of sewable circuits, AnnMarie had the idea of sculpting circuits. The original idea was a squishy breadboard consisting of conductive and insulating layers. Together with Sam Johnson, a summer research student, they came up with the idea of highly conductive and insulating doughs that could be used to build circuits. They collected a handful of common homemade dough recipes and checked resistance. A great deal of research was carried out that summer carefully measuring the resistance of the dough over time. Results from these studies created a pool of data from which the group was able to hone in on the perfect recipes as well as present to the scientific community.
We discovered Squishy Circuits while watching AnnMarie Thomas’s TED talk, “Hands-on science with Squishy Circuits.” The nature of the talk and call to play were right in line with SparkFun values and so the next day we whipped up our first batch of conductive and insulating doughs. We set up all the materials in the education tent at this year’s AVC and watched in excitement as people of all ages strolled into the booth to check out the Squishy Circuits. There’s no denying it, everyone wants to play with this stuff.
Having a fun way to introduce fundamentals of electronics and circuits to people of all ages is an incredible tool to share. We recently had the pleasure of working with a SparkFun family member, two year-old Daphne, who was willing to come in for an afternoon Squishy Circuits play date. Daphne was a wiz at putting together the Squishy Sound Circuit and we all enjoyed her sweet jams. Watching a two year-old begin to grasp the concepts of electricity is truly awesome and, yeah, pretty darn cute.
There is an amazing opportunity to tap into the imagination from the color of the dough all the way to circuit design. We had a ton of fun just playing with the food coloring to get bright dough (as evidenced by our bright purple conductive dough and flashy red and green insulating dough) and that was before we ever even built a circuit. We’d love to see what you come up with so please send any projects to firstname.lastname@example.org.
We have included recipes below for creating the conductive and insulating doughs with a few tips and tricks from their creator, AnnMarie. We’ve also included a link to a wish list of parts used in the circuits presented in the video. While the recommended lifespan of the doughs is about one month, they can be frozen for long-term storage. You might just find a few Ziplocs full of colorful dough tucked away in our SparkFun freezers – the Department of Education is always prepared to play!
General tip: We recommend adding spade or fork terminals to the ends of the wires. By crimping or soldering on these terminals, you greatly improve the surface area. This trick greatly improved our Squishy Circuits at SparkFun!
We’ve created a wish list that includes many of the items used in the circuits highlighted in the video above. This is just a basic list and we encourage you to invent exciting new Squishy Circuits using motors, sensors, etc.
And, while we’re at it, we just want to take a minute to highlight another cool project that came our way recently from Michael Candy. Michael came up with this project when he was creating a sound installation using an infrared range finder that changed the frequency of a speaker according to proximity of the viewer. The range finder worked by sending an analog signal so he thought of trying a fruit instead of the range finder and it worked awesomely! When creating the keyboard some of the fruits and vegetables had very similar sounds so he altered the effect by changing what metals were used when connecting the fruit (brass screws, galvanized nails, stainless steel etc.)