Innovation: Spinach-powered battery
Available: 2015, give or take
Grind up spinach. Layer between conductive material. Add light. Result: electricity.
Sometime in the next decade, kids might have another excuse not to eat their spinach. "But Mom," they'll plead, "I need it to charge my cell phone!"
They'll thank scientists from MIT, the University of Tennessee, and the U.S. Naval Research Laboratory, who used ground-up spinach to isolate the photosynthetic proteins that do the actual work of converting sunlight into energy. When hit with light, a spinach sandwich made up of the proteins and layers of conductive material produced a tiny bit of electricity.
Now Dr. Shuguang Zhang, associate director at MIT's Center for Biomedical Engineering, and Andreas Mershin, an MIT postdoctoral student, are trying to make the cells more efficient. They're also hoping to extend the life of the spinach, which died just hours after being ground up. The key was mixing it with a peptide—much like detergent—which kept the spinach alive for about three weeks. The goal: proteins that last a year.
Zhang and Mershin also must produce enough of a current to make the innovation commercially viable. Early attempts relied on a laser tuned specifically to maximize absorption by the spinach, which Mershin calls "a little bit of cheating." Future tests will use lights that mimic the sun's rays.
It's all a bit spinach-pie-in-the-sky. Yet the work has attracted mild interest from several energy companies, as well as Denso, a Japanese car-parts maker, which envisions using it in automobile paint. Imagine your car baking in the hot sun all day—and transforming the rays into energy. "Even if you can capture 1% or 2% of that energy from the sun," says Zhang, "you can easily turn your lights on without using gasoline." An SUV gooped in spinach? It could give new meaning to the term "green vehicle."
A version of this article appeared in the November 2005 issue of Fast Company magazine.