Squishy circuits for tiny tinkerers


Getting kids interested in electronics at a young age is a great idea. Feeding their developing minds via creative projects and problem solving is not only rewarding for the child, it helps prepare the next generation of engineers and scientists. University of St. Thomas professor [AnnMarie Thomas] along with one of her student [Samuel Johnson] have put together a winning recipe for getting kids started in electronics tinkering at a very young age.

While some 5-year-olds can wrangle a soldering iron just fine, some cannot – and younger kids should probably stay away from such tools. This is where the the team from St. Thomas comes in.

They scoured the Internet looking for Play Dough recipe clones, testing the resistance and useability of each before settling on two formulas. The first formula incorporates salt, and has a very low resistance. The second contains sugar and has about 150 times the resistance of the first formula. If you use them together, you have very simple conductor and insulator substrates that can be manipulated safely by tiny hands.

As seen in the demo video below, a small battery pack can be wired to the conductive putty easily lighting LEDs, turning small motors, and more. We can only imagine the delightful smile that would emerge from a child’s face when they power on their putty circuit for the first time.

While only two different types of putty have been made so far, we would be interested to see what other materials could be integrated – how about homemade peizo crystals?

[Thanks, Spence]


  1. Random says:

    Ok, that’s fantastic.

  2. rusty says:

    I would have loved this as a kid. also put it in my mouth

  3. mic says:

    I wanna go get play dough now…

  4. Mike says:

    What a great idea!

  5. This is a very cool idea, and reminds me of building a potato clock, or a lemon battery. I love this kind of homebrew science.

    Her daughter does look a bit young for a soldering iron, and while a soldering iron can be dangerous, so too can exploding batteries and melting plastic from short circuiting your battery pack.

    I think the right message is that you can teach your kids anything you want, but be present and involved. Figure out what they are and are not capable of, and don’t give up on them when they are making efforts to learn but aren’t quite there yet. They learn at an exponential rate, so literally the “next try” might be the one where it all “clicks”. Make sure they understand safety, and don’t assume they will remember all of your instructions to the letter.

    As a side note: I would make sure that battery pack has a PTC fuse on it, because accidents will happen with those loose wires. Safety glasses would definitely be a requirement of mine as well.

  6. Hirudinea says:

    Bet the resistance goes up as it drys out. Ok, so who’s going to be the first to build a play-dough computer?

  7. third says:

    This is simply amazing! I’m expecting lots of squishy hacks from this, and a whole new generation of throwies of course. ;)

  8. Renee says:

    I remember something I saw awhile back. It was puzzle like pieces that each represented a block of code that could control a robot.

    Once a child put together the blocks a webcam to a picture and converted it to code to upload to the robot.

    There was more than one way to do the puzzle so the child could do anything really, the puzzle shapes were just used to clear up the problems of learning syntax.

    They had like 5 year olds programming. Between that and this article I think so much could be taught at a young age.

  9. arfink says:

    Wow, this happened at the school I graduated from less than a year ago. Nice to know. :)

  10. ColinB says:

    Do you think it’s possible to create a large-scale semiconductor material to use with the conductor and insulator play-dough? How awesome would it be if you could make a play-dough transistor?!

    @Hirudinea, then you could make your play-dought computer! A “doughputer”, if you will.

  11. adam says:

    @Renee If you happen to find that post a link because I am having no luck finding it. It sound very interesting

  12. dan fruzzetti says:

    AWESOME. I will be doing this with my own 2.5yrold daughter asap. It doesn’t have to be very advanced; wire-equivalent is all we need: just stuff the terminals into the goo and push a battery in. awesome. she already loves combining coin cells and LEDs.

  13. Nikos says:

    That’s a great idea… and the “recipe” its quite easy. I have to go to the kitchen :)

  14. Renee says:


    I believe I saw it on the Adafruit blog and it was around the iRobot build platform. Also, it looks like HaD was reading my mind in a manner and posted and article close to what I was talking about.

  15. Pedro says:

    How is this better than just using small crocodile clips?

  16. Peter says:

    I might actually try this with my kids. Alligator clips are too tough for a 3 year old, but playdough won’t be.

  17. Willyshop says:

    Alright; now to go cook up some P and N type play-dough!

  18. nave.notnilc says:

    does she specify an actual number for the resistance anywhere?

  19. seer says:

    may it be slightly poisonous caused by electrolysis of Salt?

  20. Andrew Parting says:

    hydrolyss of salt in water yeilds clorine which is given off probably in too small amounts to cause trouble and sodium hydroxide. neither particular poisonous in the quantities produced

  21. seer says:

    @Andrew Parting
    Hmm… It seems that it will give of 0.2mg chlorine per second on 1A current, according to my calculation. And 0.5 ppm (1.45 mg/m3) may be safe.
    It seems acceptable in home experiments with a few mA.

  22. Andrew Parting says:

    on the other hand as a kid I would shove a 9v battery into a pack lunch bag thingy full of salt water and leave it for weeks. I turned out mostly okay…

  23. Nick says:

    Oh Wow, that is unbelievable. Maybe you could make a simple transistor with the dough? 8)

  24. 4 bits are best! says:

    Could this actually help with 3D printers? people are ALWAYS banging on about being able to ‘print’ out circuits and conductive play dough might actually be the solution.
    Oh, and making a play dough computer is actually the first thing i thought about when I found out play dough is conductive… :)

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