This helpful battery designed by John Rogers and his team at the University of Illinois is biodegradable. Moreover, it can even melt within a body without actually causing any harm.
Most batteries are not good for the environment, resulting in major waste in the world, and too many people contributing to this problem without better alternatives (even rechargeable batteries must be thrown out eventually). This biodegradable helpful battery can help reduce people's carbon footprint, as well as contribute to research on a number of other projects. According to PSFK, these could include "environmental applications wherein the device can be turned into a chemical sensor that assesses an oil spill and simply dissolve afterwards, as well as biomedical implants that deliver drugs as controlled or in response to time-sensitive events like epileptic seizures."