This article was taken from the March 2013 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by <span class="s1">subscribing online.
In 1982, Caltech chemist Harry Gray discovered that electrons "tunnel" -- skip across chains of molecules -- through proteins. This turns out to be how living things convert energy into fuel. It's all made possible by hybrid molecules called metalloproteins, which combine the flexibility of proteins with metal's ability to catalyse chemical reactions.
Gray realised that if you were trying to develop a near-infinitely renewable power generator, you might try to hijack
a metalloprotein-driven system like photosynthesis. But biological machinery is too fragile and inefficient. It wouldn't work. If you want a molecular machine that'll make power efficiently and reliably, Gray says, you have to build it yourself.
He and his colleagues envision microscale batteries with metal oxides at one end and silicon at the other, built like metalloprotein arrays in plant cell membranes. The metal oxides would absorb blue wavelengths of sunlight and use the energy to split seawater into oxygen and protons, and the silicon would absorb red light and combine the protons with electrons. And a proton combined with an electron is hydrogen, which can be used as fuel.
It could work. Artificial water splitters are much more efficient than natural photosynthesis, though scale-up is still decades away. Still, Gray is optimistic. "The natural system had to build something that could live," he says. "All we have to do is make fuel." Oh, and save the planet.
For more Big Ideas, check out the following stories:
Big Idea #1: Turn deserts into power plants
Big Idea #2: Make aeroplanes economical and rechargeable
Big Idea #3: Builds skyscrapers out of diamonds
Big Idea #4: Fuel Earth using micromachines
Big Idea #5: Put digital displays on contact lenses
Big Idea #6: Declare war on incoming asteroids
Big Idea #7: Spray Wi-Fi hotspots on to everything
This article was originally published by WIRED UK
