Improving Thermoelectric Materials with Novel NanostructureCategory: Science & Technology
Posted: February 25, 2014 09:52AM
For many technologies and devices a lot of energy is lost as heat, which is why we have been working to somehow capture that heat and make use of it. Thermoelectric materials, which can convert between electrical and thermal energy, could be especially useful here, but materials with optimal properties have proven hard to find and hard to produce. Researchers at the University of Colorado, Boulder have taken a different approach to the problem and have found a solution that could significantly improve the situation.
Thermoelectric materials produce an electrical current when there is a heat differential across it and the stronger the differential, the stronger the current. The problem is that typically electrical and thermal conductivity go together, so a material that would transmit an electrical current well would also dissipate a temperature differential quickly. What the researchers have suggested is to add nanoscale pillars on a sheet of a thermoelectric material. Heat is carried through a material as phonons, which are the quanta of vibrational energy, and these pillars will interfere with those vibrations, slowing their movement.
According to the researchers' estimates, the pillars may impair heat flow by up to half, which is pretty significant. The actual effect of the pillars may be greater than that though, as the researchers describe their calculations as very conservative.
Source: University of Colorado, Boulder