Now-a-days the biggest issue in smart phone is battery life. The Bristol robotics laboratory reported a way to charge smart phones using human urine. The harness power from urine can able to charge the microbial fuel cells.
These cells are basically converts the organic power into electricity via metabolism of live microbes. Using human waste to generate electricity is entirely eco-friendly. Currently microbial fuel power stack only holds a limited amount of juice. It is capable to make a brief call. This technology will be developed to a certain degree where the phone can be charged for longer periods.