Did you think that the refrigerator made out of mud was crazy? Wait till you hear this one. This guy used rubber bands to design a fridge and the craziest thing is that it even works, well kind of!
Stretching a rubber band heats it up. The temperature of the rubber band falls below its initial temperature when it is allowed to contract.
The folks at Applied Science used the same principle to build a small fridge. The outer body of the refrigerator is fashioned out of wood while the rubber bands act as the coolant.
The efficiency of the system is pretty low but it works, and how incredible is that! Who knows, the idea may be refined and one day might even be put into practice. You can see how the rubber band fridge was made in this video: