Sony developed a bio battery prototype that generates electricity from sugar, similar to the method used in living organisms.
As humans breakdown food for energy, the battery would generate electricity by breaking down carbohydrates or sugars through the use of enzymes. Since sugar is a natural energy source, the bio battery would be an environmentally friendly choice as it would dramatically reduce disposal issues with disposable batteries used today. Most chemicals used in batteries are quite toxic to humans and the environment.
Test cells have generated up to 50 milliwatts, which is the highest for a bio battery of this type according to Sony. Currently, it produces just enough to power music play back on a memory-type Walkman.