So I’m a hugebeliever in hands on education but you have to have the right tools if I’m gonna teach my daughter about electronics I’m not gonna give her a soldering iron and similarly she finds prototyping boards really frustrating for her little hands So my wonderful student Sam uhm and I decided to look at the most tangible thing we could think of play-dough and so we spent a summer looking at different play-dough recipes And these recipes probably look really familiar to any of you that have made homemade play-dough Pretty standard ingredients you probably have in your kitchen We had two favorite recipes one that had these ingredients and the second that had sugar instead of salt and their great we can make great little sculptures with these but the really cool thing about them is when we put them together You see that really salty play-dough well it conducts electricity and this is nothing new it turns out that regular play-dough that you buy at stores conducts electricity and high school physic teachers have used that for years But our homemade play-dough actually has half the resistance of commercial play-dough and that sugar dough is a hundred and fifty times more resistant to electric current then that salt dough So what does that mean well it means that if you put them together you suddenly have circuits circuits that the most creative tiny little hands can build on their own So… so I want to do a little demo for you okay so if I take this salt dough again it’s like the play-dough you probably made as kids and I plug it in to two leads of a battery pack a simple battery pack you can buy them at radio Shack and pretty much anywhere else we can actually then light things up So but if any of you have studied electrical engineering we can also create a short circuit if I push these together the light turns off right the current wants to run through the play-dough not through that LED if I separate them again I have some light well now if I take that sugar dough the sugar dough doesn’t want to conduct electricity it’s like a wall to the electricity If I place that between now all the dough is touching but if I stick that light back in I have light In fact I can even add some movement to my sculptures if I want a spinning tail let’s grab a motor put some play-dough on it stick it on and we have spinning okay I went through the basics we can make a more complicated circuit we call this our sushi circuit it’s very popular with kids I plug in again the power to it and now I can start talking about parallel and series circuits I can start plugging in lots of light alright And we can start talking about things like electrical load what happens if I put in lots of lights and then add a motor right it will dim We can even add microprocessors and have this as an input and create squishy sound music that we’ve done You could do parallel and series circuits for kids using this So this is all in your home kitchen we’ve actually tried to turn it into an electrical engineering lab we have a website it’s all there these are the home recipes we’ve got some videos you can make them yourself and it’s been really fun since we put them up to see where these have gone We’ve had a mom in Utah who used them with her kids to a science researcher in the UK and curriculum developers Hawaii So I’d encourage you all to grab some play-dough grab some salt grab some sugar and start playing We don’t usually think of our kitchen as an electrical engineering lab or little kids and circuit designers but maybe we should Have fun thank you
