Researchers squeeze more electricity from heat

Tag : Material Testing Machine

Researchers at Ohio State University have invented a new materialthat can generate electricity from heat in hot machine environmentsat an unprecedented rate.
The new material is called thallium-doped lead telluride.
The development could have a direct application for converting carengine exhaust heat into electricity, according to a statement fromthe university.
Using thermoelectric materials for generating power is not new. It is the group's improvements on this type of alloythat are newsworthy.
The group, led by Joseph Heremans, Ohio Eminent Scholar inNanotechnology at Ohio State University , developed a material that is effective between 450 and 950degrees Fahrenheit, the temperature range for most car engines.
"The material does all the work. It produces electrical power justlike conventional heat engines--steam, gas, or diesel engines--thatare coupled to electrical generators, but it uses electrons as theworking fluids instead of water or gases, and makes electricitydirectly," Heremans said in a statement to the press.
Heremans' group has also more than doubled the efficiency ratingwith which the previously most efficient thermoelectric materialcould convert heat into electricity, from 0.71 to 1.5.
The invention's story is also an example of how scientificbreakthroughs are really the culmination of many people's effortsover long periods of time.
Heremans credits a breakthrough development published in 2006 byresearchers at Michigan State University on the quantum mechanics of thallium and tellurium with directly inspiring him after 10 years to try a new approachto producing this type of material. Testing of the newthermoelectric material was a collaborative effort betweenHeremans's group and scientists at the California Institute ofTechnology and Osaka University.
Details on the physics behind how the thallium-doped lead telluridewas developed can be found in the journal Science .