Solar BEAM Marble Machine
We love brass here at HackSpace towers. It’s conductive, it looks great, and you can get a circuit working with it reasonably quickly, as long as you don’t expect it to look perfect.
Jack Spiggle, aka NanoRobotGeek, has used brass not just in the electrical parts, but also in the mechanical parts of his Solar BEAM Marble Machine. There’s a lot to it, so we’d highly recommend checking out the link but, in short, it takes in energy from the solar panel and stores it in a pair of
capacitors; when the charge gets too much to store, the capacitors release it into the rest of the circuit, where it powers a solenoid that pushes a lever that moves a marble around a track. Brilliant.