New Thermoelectric Material to Capture Waste Heat and Cool ThingsCategory: Science & Technology
Posted: April 23, 2012 11:02AM
A sad truth of most power producing systems, from power plants to car engines, is that a lot of energy is lost as waste heat. In the US today roughly 58% of all energy generated is waste heat. Recapturing just a part of that could improve the nation in a number of ways, by reducing use and reducing the amount of carbon released into the environment. One way to recapture waste heat is with thermoelectric materials, and researchers at Purdue University have found one with some special properties that is cheap too.
This new material is glass nanocrystals coated in a 300 nm thick layer of lead telluride. Other thermoelectric materials use tellurium as well, which is a rare and expensive material, but it only represents 5% of this design. Also most other thermoelectric devices are large disks or blocks. By coating nanocrystals like this though, the resulting strands can be woven together into a fabric that wraps around objects, like a car engine. Together this should allow for mass production at relatively low cost. The researchers are also investigating other compounds that can be used, such as polymers instead of glass and replacements for the toxic lead and tellurium. In such small quantities, the two metals should be safe, but other materials may be cheaper.
While recapturing waste heat is definitely a good thing and enough for any researcher to be proud, those at Purdue discovered this can also be used as a solid-state cooler. Passing an electric current through the material forces it to absorb heat. This opens up a range of possibilities such as clothes with built in air conditioning, or other cooling technologies.