Squishy circuits combine two of my kids’ favourite hands-on activities: play dough and electric circuits.
You can either just use conductive play dough in your circuits. Or, to extend the learning, you could mix up a batch of insulating play dough that doesn’t conduct electricity.
What you need
Conductive play dough ingredients
* Flour – 1 cup
* Salt – 1/4 cup
* Vegetable oil – 1 tbsp
* Water – 1 cup
* Cream of tartar (3 tbsp) or lemon juice (9 tbsp)
* Food colouring (optional)
Mix all the ingredients together in a pan on the stove over a medium heat, then knead to form a dough.
For more detailed instructions and other useful tips, head over to StiMotherhood.
Insulating play dough ingredients
* Flour – 1 cup
* Vegetable oil – 3 tbsp
* Sugar – 1/2 cup
* Food colouring (optional)
* De-ionised or distilled water – 1/2 cup
Mix all the insulating play dough ingredients together in a bowl, then knead. Warning – this batch will be stickier than the conductive play dough.
Apparently de-ionised water is used to prevent limescale in cars and irons. (Confession: I ordered it from Amazon and then got impatient and bought some at my local car supplies shop. Any suggestions about what to do with 5 litres of de-ionised water? ‘Do more ironing’ is not the kind of thing I mean.)
To play with the dough, you will also need a 9V battery and a battery holder with connecting wires, and some LED lights.
Before you play with your electric play dough
Before they play, show your kids what to expect and get them excited with this squishy circuits video.
The science of squishy circuits
Squishy circuits provide a perfect demonstration of how electricity takes the path of least resistance.
If an electric current has to travel through an LED bulb to complete a circuit, it will do so and light up the bulb.
But if the electricity can find an easier path (like through a piece of conductive dough), the bulb will remain unlit.
How to use the insulating play dough
Use insulating dough to bridge gaps between pieces of conductive dough.
Electricity can’t travel through the insulating dough. Instead, it has to travel through – and light up – the LED bulbs.
Benefit from my mistakes
I have a habit of seeing a cool activity online then gathering supplies and diving in without referring back to the original instructions. Which is why we first tried to power our squishy circuits with a couple of AA batteries.
Underpowered circuits are a bit of a dampener on kids’ enthusiasm.
Luckily J(9) and C(11) were happy to switch to regular play dough and reconvene with the conductive sort on another day, once I’d bought some 9V batteries.
AA batteries are probably fine if you have enough of them (and sufficient battery holders), but I’d recommend using 9V if you can.
Finally – do wipe down your metal wires after they’ve been in contact with the conductive play dough, so they don’t rust.
I first came across the idea of squishy circuits at StIMotherhood. Do head over there for tips on how to get the most out of squishy circuits play.
And see this great TED talk all about squishy circuits by the lady who invented them.
More fun hands-on science
The amazing water trick – Investigating density
Alien soup – How to separate mixtures
Chemistry for kids – How to separate water into oxygen and hydrogen using electrolysis
The science of how candles burn
How to make a balloon hovercraft
Gummy bear science – Osmosis in action
Edible science with ice and salt
Elephant’s toothpaste – Fun with catalysts
Creative science with ice, salt and colour
Clay model of the Earth’s layers
How to simulate the rock cycle with crayons
How to make butter – Fun with emulsions
Fun with acids and bases – How to use red cabbage as an indicator
Fun with polymers – How to make slime and plastic
Hands-on science – Is light a wave or a particle?
A note to my kind friends who are wondering what became of my next post about our Spanish adventure: This week someone with a huge Facebook following (I wish I knew who) shared my elephant’s toothpaste post, resulting in 70,000 extra visitors here.
Once I’d picked myself off the floor, I was inspired to get around to finishing this post on squishy circuits.
More about Spain soon. 🙂
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I’m appreciatively linking up here:
The Weekly Wrap-Up – Weird Unsocialized Homeschoolers
Science Sunday – All Things Beautiful
How cool! I didn’t know that you can change the conductivity of playdohs by changing the ingredients they are made from. It seems to be a case of, the more I learn, the more I realise that I know very little! 🙂 Also thanks for sharing the lessons that you’ve learnt. They’ll certainly save me a lot of time when we try this experiment.
Congratulations on the huge number of visitors! Your blog is full of wonderful examples of learning so it’s really good that you’re reaching such a wide audience. Many will be inspired by what they read here. 🙂
I know what you mean, Hwee – when I saw this I had a great desire to find out what it is about the conductive v. insulating play dough that makes it conduct electricity or not. (I was reminded of our electrolysis experiments, too.) I’m currently working my way through a GCSE chemistry book… I’m hoping that by the time I’ve finished it I’ll be a bit more clued up about ions etc. So much interesting stuff to learn, so little time..! 🙂
Thank you for your kind words. It was a rather surreal experience seeing traffic spike like that, and I’ve had to focus firmly on the fact my primary reason for blogging is to connect with kindred spirits – so thank you for taking the time to comment. 🙂
What a cool idea!
Thanks, Jessy!
Hi Lucinda,
Thanks for sharing this post. I knew you could change the conductivity of play dough and now I know how!
I use distilled water for making red cabbage dye as an indicator for acids and bases as tap water can give slightly odd results. Deionised water is slightly different from distilled but would probably work as well.
Hi Jennifer,
Thank you so much for the info about distilled water. It must’ve come up on an Amazon search and I just assumed they were the same. I have so much to (re)learn about chemistry!
Thanks, too, for the tip about red cabbage indicator. I’ll try using some of our stock of deionised water next time we mix up a batch of that.
That’s an awesome experiment!!! I’ve never seen that before. Congrats on the huge influx this week! That’s wild! Have a great weekend and thanks for sharing this cool experiment!
Thanks, Jen. I hope you’re having a great Easter weekend, too!
Oh my goodness! My boys would absolutely love this activity. Thanks for sharing!
I hope your boys have fun with it, Tara!
Your posts are always amazing! You inspire me to be a better homeschooling mom. 🙂
That’s the nicest thing anyone’s said to me in ages, Maria! Thank you. 🙂
Wow! What a boost of visitors! That’s wonderful Lucinda, I’m not surprised you’ve inspired many to get down and dirty with science 🙂
This play doh is such a neat idea – I have a slew of new nieces and nephews (who aren’t teens and therefore think everything I come up with is fun) that I’m sure will love this – can’t wait to try this out!
Thanks, Marie! I bet you are a very favourite auntie. 🙂
I’m looking after my 4 year old nephew once a week this term. I’m so excited, I have a long list of fun, messy projects to play with! I bet my older kids will join in too.
I have seen this sort of thing, but I have never done it. This is a wonderful post to refer to. Thanks for linking it up to Science Sunday.
Thank you for hosting Science Sunday, Phyllis!
Lucinda,
Wow! What a lot of visitors! Maybe that unknown reader will return and share this post on FB as well. I’d never heard of squishy circuits before. I must show my girls. It’s such a fabulous idea. I’m bookmarking the TED talk. (I love TED talks!)
Distilled water and ironing… It would take me years to use that much water in my iron. I bought a new iron last summer (or was it the summer before?), intending to wear beautifully ironed clothes all the time. Alas, I soon abandoned that idea. Writing or ironing? It wasn’t hard to choose!
Sue,
Thank you for your lovely comment! I love TED talks too. I’d like to create more time in my routine to watch them. I enjoy listening to your podcasts while I straighten my hair on a Friday morning. I wonder what aspect of my routine I could link with TED talks?
I’m very glad you chose writing over ironing. For years I’ve only bought clothes that look okay straight from the airer!
What COOL experiments. I haven’t visited in a while and your beautiful kids are just growing up way too fast. I know they so loved doing all of these science experiments. Congrats on the HUGE visitors. That is so awesome. 🙂
Hello Karen! I often think of you and Keilee, you are always an inspiration to me. Thank you for your kind words and for stopping by to say hello. 🙂
Fun! I had to laugh at myself because I thought the top video was one your daughter had done. Imagine my surprise when I watched it and saw that it wasn’t her after all!
Thanks for your lovely comment, I appreciate it very much 🙂
Claire, I’m loving following your journey. You have a real gift for moving and inspiring others.
LOL re the video. I think C(11) would be delighted to make a film like that. Sylvia’s very talented, isn’t she?!
I’m glad to know I’m not the only one who jumps in, and is halfway through a project before I really know what I’m supposed to be showing the kids 🙂 We always use our Leapster battery holder full of AA batteries as a power source for electric playdough – I never remember to pick up a 9V.
70,000! That’s fantastic 🙂
Leah – I think just jumping in is the secret to getting these sort of projects done! Yes I think a lot of AA batteries would be fine. Not the rather pathetic two AA’s I offered my son!