This is for a high school project that I'm doing. The sensor should be able to detect the movement of a moving inanimate object and convert into electrical energy, and be fairly cheap to buy.
I have looked into a few sensors but most of them seem to be geared towards detecting HUMAN movement, eg. PIR sensors. I am looking for the type of sensor that is able to detect non-human movement at close range (about 1/2 metres). Any suggestions?