ACS 2007 Chicago: Diet coke won't power my phone
I've just been to a great talk about making a fuel cell that can be powered by sugar. I liked this talk for a number of reasons, first because it's a great, simple idea that if developed could be a real commerical success. Second, it was work done by an undergraduate as a research project. What better way to be inspired to carry on in research than to do a tangible project. And one that could perhaps bag someone a lot of money one day.
So here's the story: Tamara Klotzbach, a final year undergrad working with Shelley Minteer at Saint Louis University has developed an enzyme-based electrode fuel cell system that can run on sugary solution, and has so far been used to power a pocket calculator - but the big sell here is the promise that all the trappings of modern life - cell phones, laptops, ipods - could be powered by a can of fizzy pop. Pretty cool, no?
Klotzbach coated an electrode with a conducting polymer, based on the dye Azure C. Onto this she deposited a membrane made from modified chitosan (a complex carbohydrate sometimes made from the shells of shrimps and other crustaceans - tasty). This modified chitosan layer provided a protective environment to store enzymes until they are needed to convert sugar to energy and so power an electrical system. The enzymes (dehydrogenases) are the same as the ones used in our bodies to power us.
Because these are natural enzymes, not highly engineered catalysts, they can work with any natural sugar solution. Including "all the junk that would be in Kool-Aid," Minteer told me. The bad news? Diet drink fans will have to switch to the full-sugar varieties to use this technology - artificial sugars or sweeteners can't be broken down by these enzymes.
Other enzyme fuel cells exist, inculding those under development by Derek Lovley at the University of Massachusets, but Minteer claims the difference with her system is that they isolate the enzymes from cells, rather than just using cells. The improvement she gets is a better efficiency, becuase the enzymes - once released from their protective pockets - can act directly on the sugars rather than having to work their way through the cell walls.