So a lot of attention is being paid to hydrogen fuel cells as an alternative to gasoline. But Dr. Stanley Kravitz of Sandia National Laboratories sees another route, which uses similar technology: fuel cells that harness energy produced by glucose, a basic form of sugar. Glucose is cheap and abundant, and unlike hydrogen, it doesn't require larger compounds to be broken down in order to access it. Glucose is a natural fuel for the human body and thus the conversion processes are quite well-known, leading Dr. Kravtiz to believe that "If evolution figured it out, we should be able to figure it out." There are a few other companies working with glucose fuel cells as well, including one which has been issued a patent for its sytem. The reason we haven't heard much about it is because of the technology's woefully low efficiency, which will need to be raised a millionfold (literally) before it's taken even remotely seriously.