A few years ago I had to mix a lot of fine powder samples with a binding agent for X-Ray analysis, the mix ratio is 8 grams of sample and 2 grams of binding agent. This job was usually made by hand, mixing both components in a small tray with a spatula for 4 minutes at least; but when I had to mix 50+ samples this seemed like a very boring task. I folded spiral of light cardboard, like the one used for bussines cards and put it into a test tube, I poured in both the sample and the binding agent, closed the tube with a cork and put it over a small car toy motor that made it turn at slow rpm, for speed control I used an old toy train transformer. The test tube was slanted so the spinning spiral made the mix go up and fall to the tube's bottom, like and Archimides' screw. My "laboratory dry power origami mixer" worked very well, I scanvenged every test tube at the lab, folded 50+ spirals and went on making really good mixes. Later on I added an electronic timer circuit to the motor. An additional benefit made my life even easier regarding the samples' identificaction: I wrote every sample's ID code on the spiral and I never lost track of a single mix.
