This is a bit creepy: Researchers at Case Western Reserve University, USA, have successfully managed to turn a cockroach into a battery. The research relies on a Cockroach’s diet. As a cockroach eats, it produces trehalose – a complex sugar. An anode is introduced into the cockroach’s gut coated in an enzyme that breaks the trehalose down into two simpler sugars. These are then broken down again by another enzyme so that the electrons bound up in the sugars are set free, which then rush toward the cathode, completing the circuit.
The amount of energy generated by the process is only 100 microwatts of energy at 0.3 volts. This is the first time that energy has been derived from a living thing like this.