Erez Lieberman-Aiden and his team at Harvard University in the U.S. propose to develop a low-cost microbial fuel cell (MFC) to power cell phones in Africa. Certain naturally occurring soil microbes produce free electrons during the course of their ordinary metabolic processes, and MFCs will recharge themselves using power derived from these soil microbes. These fuel cells do not require any sophisticated materials to build, and can be easily assembled using locally available materials.