Credit: AM. CHEM. SOC.

Nano Lett. doi:10.1021/nl903267n (2010)

Waste heat from vehicle exhaust pipes and industrial waste streams could offer a sustainable energy source, but current technologies for harvesting thermal energy are costly and inefficient.

Ray Baughman at the University of Texas at Dallas and his colleagues have created a 'thermocell' that can be wrapped around pipes (pictured). Made of carbon nanotube electrodes, the device is three times as efficient as conventional platinum-based thermocells. The difference in temperature between the two electrodes creates an electrochemical potential difference, which the thermocell uses to generate electricity.

One of the team's prototypes acn be attached to hot nuclear-reactor pipes.