Scientists at the Massachusetts Institute of Technology are developing a new type of bacterial battery that is only half the size of a human cell and is powered entirely by microbial bacteria.

　　Professor Belcher of the Massachusetts Institute of Technology mixed harmless E. coli M13 phage with metal cobalt and applied it to a stamped silicon film to create a soft micro-battery. This battery is suitable for large-scale production and does not require too much capital investment. In theory, this technology can actually transform any surface into an energy storage device for use in large computers and miniature cancer or heart disease detectors. Professor Belcher said: "It is a very special idea to use stamping technology to make batteries. We can make the battery very small and provide power for various micro sensors." The

　　latest research results are that by stamping a basic material (such as silicon), the negative M13 phage and the positive metal cobalt can automatically converge according to their corresponding electrodes and stamping patterns. This means that the cost of this battery will be lower and the battery efficiency will be higher. If silicon is used as the basic material, soft, bendable and deformable batteries can even be produced. The power of this bacterial battery is about twice that of traditional biological batteries. In addition, this battery is very small, with a diameter of only about 4μm.
　　Professor Belcher explained that in nature, this bacterium will release excess electrons to iron-rich sediments, but there are not many such sediments in nature, so the electron content in this bacterium is always full, and it needs a way to release electrons. If the electrode is placed in this iron-containing sediment and connected into a circle, the bacteria can release electricity. Bacterial batteries need to be assembled at room temperature, a relatively neutral pH value must be maintained, and some more troublesome metals such as lithium or cobalt should be used as little as possible. In terms of application, Professor Belcher believes that because bacterial batteries are very small, they will generally be used in small electrical devices in the early stage, such as chip laboratories, medical implants, etc.