Innovation Pipeline

For more than 200 years, scientists have observed the phenomenon of specific materials’ dual personality to convert heat into electricity and electricity into heat. Known as the thermoelectric effect, the challenge for scientists and researchers has been how to harness this energy conversion.

A team of researchers from MIT and Boston College have developed nanotech structures that can serve as either micro-cooler and power generators and thus greatly boost energy efficiency. And that’s welcomed news for solar innovators, semiconductor engineers and others in the heat dissipation business looking to dramatically boost efficiency.

The problem the researchers tackled is a classic one. Most materials that conduct electricity also conduct heat, which results in rising temperatures for materials. Therein lies the rub.

MIT and Boston College researchers improved the new material’s relative performance by simply crushing the material into nanotech sized particles and then performing an atomic re-shuffling. The reconstituted material’s composition had fundamentally new characteristics that helped slow the movement of phonons, a mode of quantum vibration –which involves helping conduct heat.

The actual nanotech structures are comprised of bismuth antimony telluride, a common semiconductor alloy. The researchers benchmarked the material’s ‘figure of merit’ at 40 percent, a measurement of the material’s relative performance. The scientists published their results of the team’s research in a recent online version of the journal Science. The research was funded by U.S. Department of Energy and by the National Science Foundation.

The promise of harnessing energy from the thermoelectric effect will also give a boost to new generation of technology designed to lower energy consumption and reduce carbon release. By Lee Bruno