Sugar is full of energy. I'm sure that you already know that by now, especially if you've been around kids with candy any time recently. Some of that energy is extracted when different crops are turned into biofuels, for example when corn is converted to ethanol. It is also possible to made a sugar-based rocket fuel. But, what about using sugar in batteries? Sony has recently shown some "bio-batteries" which use enzymes to break down carbohydrates in glucose. At this point, not enough energy (50 mW per cell) is being extracted to make these batteries practical, as you can probably tell from the pictures. But, Sony is already daisy-chaining these batteries together to get more juice from them, and you can see that they are able to get them to power an MP3 player. So, although I wouldn't expect to see any cars being powered by these sugar-based batteries any time soon, it is an interesting project.
See a video after the break!
[Source: Tokyo Mango via Engadget]