One of my lectures at university was taught by a robot, and would dance on and off to keep us entertained. With the actual lecturer in the room on standby feeling very nervous his robot will walk off the desk.
I used a £5000 3d printer I built to make fancy sugar structures. I was an incredibly cost ineffective way to make custom shapes with sugar, but it made the lab smell like cotton candy. Unfortunately molten sugar (caramel) started leaking everywhere and made a sticky mess. Was an absolutely horror to clean up.