Manufacturing cheap thermoelectric materials

The researchers were led by Dr. Ole Martin Løvvik, working at the Center for Nanoscience and Materials Science, University of Oslo, Norway, claiming to have made thermoelectric materials (at the nanoscale ) cheap, can take advantage of the heat energy available everywhere in everyday life.

Thermoelectric materials, which were discovered in 1821, are basically the formation of a voltage generated by the difference in temperature on a material (the temperature difference between two thermocouples). made of two different types of metal.

"On the outside, thermoelectric materials look simple, but actually the inner electrons are working very actively," said Dr. Ole Martin Løvvik, "The nature of thermoelectric materials is thermal engines, however, the temperature difference (of liquid solution) generates electric current (the movement of electrons) and vice versa, the movement of electrons also causes a change in temperature. "

However, this technology is limited only to specialized applications such as: executing tasks in distant spaces, used in thermoelectric generators using decay heat from fecal processes. Radioactive decay of Plutonium isotopes.

Efforts to bring this technology into general use such as producing electricity from the harvesting of waste heat from industries and in people's daily activities, have not, (yet) become a reality. because the cost is too expensive.

"The main problem is to create good thermoelectric materials (with high heat resistance and low resistance) to limit the thermal properties of thermoelectric materials" , according to Løvvik.

Researchers have overcome this drawback by integrating nano barriers into conventional semiconductor materials, in order to reflect (re-emit) vibrational waves of certain frequencies generated by particles. "hot" energy .

"It is possible to select the appropriate frequency, to maintain the electrical conductivity while still significantly reducing the thermal characteristics of the thermoelectric material" , Løvvik explains.

The fabrication method (nano barriers) involves cooling semiconductor materials to a temperature (-196 ° C) using liquid nitrogen to make the semiconductor material blocks brittle and Less sticky, then crushed (using crushers) into nanoscale particles. These nanoparticles are then basically compressed together in a controlled manner, to form the necessary nano-size barriers.

"We use the same type of crusher, which is used to make dyes, this is a long-standing technology, but most importantly, this mill is cheap and easy to upgrade," Løvvik to speak.

The researchers' calculations show the prospect of recovering about 15% of all energy losses in a wide range of applications. Researchers are now in agreement with a major automaker to install thermoelectric materials in the exhaust pipes of cars.

"This move is just the starting point for using this cheap thermoelectric material to exploit the large amount of waste heat available, everywhere in daily life," Løvvik added.