How to charge your smartwatch with your trousers

A team of renewable energy researchers at the Chinese Academy of Sciences has developed a type of solar cell that can be woven into fabric, harvesting energy when exposed to the sun.The cells are made using a mineral called perovskite, which makes them not only cheap but also extremely efficient. Normal, flat cells made from this material have an impressive efficiency of 20%, and can be made 400 times thinner than conventional silicon cells.Weaving the cells into thread is no easy task though. T