Humans are always looking for the next great big thing in energy sources. We need something that can continuously give us power without damning the whole world with doom. Now, researchers have created a small power generator that will run on human spit.

Turns out, there's a lot of organic stuff in our saliva, and it can power microbial fuel cells. The fuell cells produce just one microwatt, and it is enough to power a simple on-chip applications.

It uses a graphene-coated carbon cloth anode, and the energy comes from the bacteria inside the cell breaking down organic spit and releasing electrons.

A similar technique has been done before with wastewater and while saliva is definitely less disgusting than shit, it can probably be more useful for biomedical electronics. Saliva is just an example of liquid that contain organic matter, though any other liquid should work as well.

[Penn State]