Zapping raw materials in a microwave oven and drying the resulting solution produces a black powder (top) made of hexagonal bismuth telluride nanoplates (bottom).

High-efficiency thermoelectric materials could lead to new types of cooling systems, and new ways to scavenge waste heat for electricity. Researchers at Rensselaer Polytechnic Institute in Troy, New York, have now developed an easy, inexpensive process to make such materials.

The materials made by the RPI team already perform as well as those on the market, and the new process, which involves zapping chemicals in a microwave oven, offers room for improvement. “We haven’t even optimized the process yet,” says Ganpati Ramanath, a materials science and engineering professor at RPI. “We’re confident that we can increase the efficiency further.”

What caught my eye here is that the material is a form of nano particulate, its produced in an evidently very simple process and it has a very high efficiency.  This type of technology as the article notes could have a great number of applications.  In a car one could conceive of replacing the mechanically driven alternator with something like this or supplementing it, this would essentially be using waste heat to provide electricity and would increase gas mileage.  There are many other places where heat scavenging would make sense and have an impact if the materials and system were cheap enough.  This goes back to a fundamental issue, energy efficiency costs money and if the cost of burning a tiny fraction more fuel over the life of the system (which can add up to biggish $) is less than the energy scavenging equipment then the equipment will not be installed unless the added cost is passed on to someone.