Harvesting Waste Heat and turning it to Electricity
Unlike existing heat-conversion devices such as refrigerators and steam turbines, the devices of Bergfield and Stafford require no mechanics and no ozone-depleting chemicals. Instead, a rubber-like polymer sandwiched between two metals acting as electrodes can do the trick. Car or factory exhaust pipes could be coated with the material, less than 1 millionth of an inch thick, to harvest energy otherwise lost as heat and generate electricity.
While Researchers at Northwestern Universitycreated a new material by dispersing nanocrystals of rock salt (SrTe) into lead telluride (PbTe). This kind of nanoscale increased the scattering of electrons, which reduced the material’s overall conductivity. The Northwestern team’s study offers the first example of using nanostructures in lead telluride to reduce electron scattering and increase the energy conversion efficiency of the material. The researchers say the resultant material is expected to enable 14 percent of waste heat to electricity.