These days biological fuels are revolutionizing the technology. Minteer and Tamara Klotzbach from St. Louis University have developed a new type of fuel cell that can turn calories into electricity. The cell functions in a similar manner to the living cells that produce some energy breaking sugar molecules to produce electrons. The agents used in both these cells are enzymes.
The major problem that was encountered to sustain the production of electricity on these fuel cells was that these enzymes degraded in few days and the fuel cells unlike the living cells were not capable of producing new enzymes. The researchers have found a solution to this problem. They have developed polymers that wrap around an enzyme and preserve it in a microscopic pocket. This pocket ensures that the enzymes remain active for few months as it provides ideal microenvironment for the enzymes.
If the technology becomes viable for mass production, these cells will be useful in many applications like powering small electronic gadgets like cell phones using your favorite soft drinks as fuel.