Instead of doing the usual circuits lab I decided to have the kids make light up holiday cards. Fortunately I found this great website on Sparkfun with templates you can download for FREE and I still had some LEDs left over from the last time we did this years ago. You can order all the stuff to do these from Sparkfun, but I just happened to have the lights and button batteries. I did not have copper tape but that got me thinking… can’t we just use aluminum foil? So a little searching on the internet and yes, people use foil for this as well.
The lights I used were from 15 piece “Gumdrop” LED assortment from Evil Mad Scientist, that I had picked up at the Exploratium. Amazon also sells LED, and you can probably pick them up at Radio Shack if you’re lucky enough to still have one near you.
Here’s my card and the aluminum foil circuit inside.
I didn’t have the button to turn it off or on or the fancy button holder. I just put a little piece of scotch tape around the side of the battery to keep the loose piece of foil from touching both the top and bottom of the button battery (short circuiting). When you squeeze the card over the button battery it closes the circuit and lights it up.
A couple of the kids tried using the conductive paint but it was really hard to get a nice line of paint and it didn’t actually seem very conductive at all. The foil was easy and you don’t have to wait for it to dry. There was also a window template and light up gingerbread house. You can also find robot templates or have the kids make up their own.