Researchers at the University of Massachusetts
have discovered a microbe
that can metabolize
sugar into electricity with an efficiency as high as 80%. An iron-oxide-reducing organism, Rhodofax ferrireducens
does not need a mediator
to transfer electrons directly onto an electrode
The technology promises to challenge fuel cells and batteries in powering stationary and portable devices of all sizes. "Bio cells" made of the bacteria would not only be less toxic than chemistry-based power cells, they would also be simpler in operation.
In addition, the conversion process produces far less heat than a fuel cell, making them suitable for applications that require human contact. Portable devices would be able to incorporate such cells with no fire or explosion risk.
Producing CO2 as a by-product, the microbe can theoretically produce enough energy from a cup of sugar to power a 60-W light bulb for up to 17 hours. The remaining issues involve getting a high enough voltage and the speed of sugar-to-power conversion.
The current test rig uses an unpolished graphite electrode, but improvements in the electrode's material and surface construction will improve the conversion process. I can forsee using spongelike electrode that may also lend itself to use as a containment and packaging system. The question I see here has less to do with the technology's success than to wonder how will society adapt to a potentially low-cost source of nearly limitless (sugar is an easily-renewable resource) electrical power.
This could completely turn the energy equation on its head. Imagine having a vat in your basement that provides enough power for the next-generation low-power devices that will populate your home? A household using OLED displays, chipscale devices, and high-efficiency cooling and heating systems may even be able to be self-sufficient.