Prototyping circuits on breadboards is always frustrating for me. I’ve never been a master of fine motor control, and I have a hard time getting tiny pins and wires into the right row of minuscule holes. I thought it would be easier if I had some kind of putty, like Play-Doh, but conductive: then I could just take a lump of the stuff and stick everything that I wanted wired together into the lump, without straining my eyes and fingers. There are thermal putties and conductive adhesives that could probably be adapted for this purpose, but after looking around for some options, I decided it would be easiest just to make it for myself, and so I started searching out Play-Doh recipes.
Ultimately, the easiest one to make turned out to be ItsYourDime’s edible peanut butter play dough recipe on Instructables. Soon, however, I realized that this recipe actually presented a challenge: I love peanut butter, and if that’s what my putty was going to be made of, I wanted to be able to eat it at the end. That meant that I was going to have to make it conductive without making it gross or poisonous. I needed a conductive but edible ingredient to blend into the peanut butter. The solution, of course, was graphite powder. Graphite is flavorless and it’s just carbon, so eating it shouldn’t have any harmful side effects; after checking the materials safety data sheet to make sure, I set to work. The recipe is after the jump.
Ingredients: 2 parts honey, 3 parts peanut butter, 4 parts dry powdered milk, 5 parts graphite powder.
Directions: Mix ’em up. That’s it. You’re done.
Be careful not to inhale the graphite or get it in your eyes. The end product looks kind of gross, but it actually tastes pretty good. Don’t eat too much of it, though: graphite isn’t harmful to eat, but it’s not meant to be food. If you want to store the stuff, put it in tupperware or wrap it in something air tight and put it in the fridge.
I’m still working on improving the recipe. As it is, the putty still has a lot more resistance than I’d like, and I’m looking for other blends or ingredients that will make it more conductive. I’d also like to make it look a little more appetizing. Drop a comment if you have any ideas.