Thermoelectric materials, materials which generate voltage when they are subjected to heat, or when a voltage is applied become hot on a side and cold on the other, are not new. In fact they've been around for nearly a century. Though understood, thermoelectric materials didn't see practical applications until the 1960s, with work done by former MIT professor and president Paul Gray.
The cornerstone of the research is
that, even in the present, thermoelectric materials are typically
very inefficient. An efficient thermoelectric material must be good
at conducting electricity, but not heat, a property most do not
possess. A current MIT professor, Mildred S. Dresselhaus, and her
team are working to address the issue with new composite materials.
What the team found is that engineering tiny structures into the material can alter the conductive behavior. Even structures as small as a few billionths of a meter interfere with the flow of heat, but allow electricity to travel unobstructed. The structures could be as simple as a matrix of nanoscale particles or wires.
Dresselhaus began her work in the 1990s, and the US Navy took interest. Air conditioning systems and power generation in submarines keep them from being truly silent, and advanced thermoelectric materials could provide a way to reduce both. Her current research in semiconductor materials and nanostructures is sponsored by NASA.
Recent advances in thermoelectric materials have garnered attention from even automotive manufacturers. Most of the energy created from combustion engines is lost as heat, thermoelectric materials may provide a way to utilize this heat in the form of electrical generation for systems in the vehicle. Other technologies, such as photovoltaics, most commonly seen as solar cells, could benefit from the materials as well, using not only the sun's light, but its heat to generate power. Materials could even be built into microchips, greatly enhancing their heat dissipation properties, allowing either cooler running chips, or even faster processing.
The work is not simply theoretical. At least one company has had minor success with a thermoelectric seat cooling device for automobiles. As technology moves, maybe we could see these new materials in every day devices, like kinetically powered thermoses that keep drinks cool or hot or solar-powered passive cooling systems for car interiors on hot summer days.