Paper Potentiometer
What? I know. It is a mouthful, and also known as a pot (as this website points out in jest).
Anyway, I made one today (yes *made*). This makes me very happy, because through the process of making a potentiometer, I now know how they actually work (rather than the vague understanding I had before). If you watch the video below, you can see the little LED in the top left corner fade as the paper tab moves across the strip. The pot is restricting the flow of electricity to make this happen -a bit like the the dimmer you have on your livingroom light switches. I was inspired by this tutorial on the wonderful website: How to Get What you Want (please visit, go now, it really is awesome!).
So, to make the pot I used paper, conductive tape and thread, and watered down Bare Conductive paint as the resistor. Last year we made some tests with conductive paint, and discovered it had a lot of resistance when you add water, so I replaced the fabric they use in the tutorial with the paint (which also makes more sense when using paper).
Next step is to hook it up to my computer and get the data from the resistance to control something else, and try it out with some paper-pop-up-mechanisms. Oh and some cool designs. Yippee!
p.s here is a really good BBC page about resistance. Don’t be put off by the simple looking cartoons, it really is quite a good refresher for people (like me) who have been out of science education for a while.
*update: I’ve just seen this page on the Kit of no Parts website. It has several types of paper potentiometers, that are very well made by Jie Qi.