This device generates energy when you walk

A special energy harvester is attached to the knee that bears the most strain when walking. The device does not cause any discomfort to its wearer. 

Experts at the Chinese University of Hong Kong have built a device that is fixed to your knee to generate energy when you walk. It can be used to charge mobile phones or other devices. 

The gadget weighs only 307 grams and does not disturb its wearer in any way, which was confirmed in multiple trials. It is made up of two parts: the top part is just above the knee while the bottom is below it. They are connected with a special piston that transforms rotational movements into linear ones.

The piston also applies pressure to a carbon fiber strip. As the strip is restructured, it generates energy. The device generates 1.6 microwatts of power when its wearer is walking at a leisurely pace.

The gadget is currently being tested on soldiers, mountain climbers and athletes. All of these professions require constant activity, which would make the device a good fit for them.