Researchers at the Massachusetts Institute of Technology (MIT) and Rutgers University have developed a new method of enhancing the efficiency of thermoelectric devices using embedded nanoparticles, structures created by embedding one material into another. The new method may have the potential to widen the use of thermoelectric devices.
In cooperation with graduate student Bolin Laio, postdoctoral researcher Mona Zebarhadi and research scientist Keivan Esfarjani, MIT professor Mildred Dresselhaus and mechanical engineering professor Gang Chen manipulated the composition, dimension and density of embedded nanoparticles to maximize the thermoelectric properties of the host material.
The new method builds upon previous research completed in the early 1990s for the U.S. Navy by Dresselhaus, in which nanoscale materials were discovered to be capable of exhibiting properties different from those of larger pieces of the same material.
Drawing upon methods developed by optics researchers attempting to create “invisibility cloaks” out of light-distorting nanostructure materials, the team employed similar methods to “embed particles that could reduce the host material’s thermal conductivity while keeping its electrical conductivity high.”
A computer modeling of the new altered material reveals that it could exhibit high electrical conductivity, low thermal conductivity and the “optimization of a property known as the Seebeck coefficient, which expresses how much heat an electron carries on average,” parameters that are key to “an effective thermoelectric system.”
