Ferrofluid is an amazing magnetic fluid that was originally invented by a NASA engineer to explore the idea of moving liquid rocket fuel in zero gravity environments using magnets. Steve Papell accomplished this by suspending tiny magnetic particles in liquid fluid. These days this liquid is being used to build dynamic speakers that visualize your music. Take this Skuyketec R-Shaped Ferrofluid Visualizer: it has 8 color modes for you to choose from. As you play music, the ferrofluid changes shape in real-time.
You get a tiny magnet to interact with the liquid manually. This is an audio visualizer, so it can react to any sound around it, including typing and nature sounds. This ferrofluid speaker has a 400mAh rechargeable battery. It uses a microphone to pick up noises around it.
