Medicine of the future is going to use various micro and nano-devices. They can diagnose diseases or treat them (deliver drugs, for example). Many of them would be ingestible and they need to be powered somehow. The team of Christopher Bettinger at Carnegie Mellon University is developing special type of batteries that are non-toxic and can be eaten by humans.
Credit: Bettinger lab
The trick is in using the melanin pigment that is natural part of skin, eyes or hair. Melanin absorbs not only ultraviolet light and protects humans from damage but it also binds and unbinds metallic ions. That is useful property for batteries.
The researchers said that the 600 milligrams of active melanin can power 5mW device for 18 hours. It cannot provide much power but it can be sufficient for very small sensing or drug delivering electronics. Next to melanin, the researchers are also working with other biomaterials like pectin. Safe packaging of these batteries is also under development. When these new technologies are going to bu used in practice, is not known.