Another great invention that will brighten up our paths is the eco-friendly lighting instrument by designers Jia Peng, Cheng Peng, and Wang Dong Dong called the Bottle Light. It requires no external power to produce light. What it needed is an empty bottle like a cola or mineral water bottle. All you have to do is to replace the bottle cap with the Bottle Light that uses LED light. After replacing the bottle cap, you now need to compress the air in the bottle repeatedly so that the piston of the bottle light will move up and down. This process will now changes mechanical energy into an electric energy the let the LED light to power on.