Four microbial fuel cells, placed side by sideCOURTESY OF KELVIN GREGORY, CARNEGIE MELLON UNIVERSITY
THE DEVICE: This tiny biological fuel cell, the smallest of its kind with a total volume of just 0.3 microliters, was built using microfluidics and relies on bacteria to produce energy. Bacteria colonize the anode, the negatively charged end of the system, and through their natural metabolism produce electrons that flow to the cathode, creating a circuit. Together, the anode and cathode are only a few human hairs wide, but the tiny circuit generates a consistent flow of electricity.
WHAT'S NEW: In 2008, researchers at the University of Illinois at Urbana-Champaign created a 3 millimeter square hydrogen-powered fuel cell, hailed as the world's smallest fuel cell at the time. The following year, a team at the University of California, Santa Barbara, produced a microbial fuel ...
