New ‘paint’ could allow surfaces to convert heat into energy

22 Nov 201617 Shares

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Painting for power? Image: Nito/Shutterstock

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Researchers claim to have developed a new thermoelectric paint which, should it be scaled up, could enable walls and other surfaces power your house.

Investigating a way to conserve heat on curved surfaces, where a “considerable amount” of heat is inevitably lost, Korean researchers may have landed on the perfect solution.

Prof Jae Sung Son co-led a study at the Ulsan National Institute of Science and Technology (UNIST) in South Korea. His team presented a new type of high-performance thermoelectric (TE) materials that possess liquid-like properties.

These newly developed materials, according to research published in Nature Communications, can be directly brush-painted on almost any surface.

thermoelectric paint

Converting changing temperatures into voltage, thermoelectric devices are already in use, but they are often shaped in rigid square, rectangle constructions.

When implanted into curved objects that emit waste heat – such as refrigerators, engines and  power plants – the bad fit results in obvious energy waste.

According to the UNIST research team, the use of liquid-like TE materials has been overlooked for years, thus their work on the area.

“By developing integral thermoelectric modules through painting process, we have overcome limitations of flat thermoelectric modules and are able to collect heat energy more efficiently,” said Son.

“Thermoelectric generation systems can be developed as whatever types users want and cost from manufacturing systems can also be greatly reduced by conserving materials and simplifying processes.”

(a) A conventional planar-structured TE device. (b) Scheme of power generation of the conventional TE generator and the painted TE generator on a curved heat source. Image: ‘High-performance shape-engineerable thermoelectric painting’ in Nature Communications

(a) A conventional planar-structured TE device. (b) Scheme of power generation of the conventional TE generator and the painted TE generator on a curved heat source. Image: Park et al in Nature Communications

The thermoelectric liquid contains the thermoelectric particles bismuth telluride (Bi2Te3). Using the molecular Sb2Te3 chalcogenidometalate as a sintering aid for thermoelectric particles, with ZT values of 0.67 for n-type and 1.21 for p-type painted materials that compete the bulk values, a suitable ‘paint’ was created.

Devices directly brush-painted onto curved surfaces produced the high output power of 4.0 mW cm−2. This approach paves the way to designing materials and devices that can be easily transferred to other applications.

“Our thermoelectric material can be applied any heat source regardless of its shape, type and size,” said Son.

“It will place itself as a new type of new and renewable energy generating system.”

Gordon Hunt is senior communications and context executive at NDRC. He previously worked as a journalist with Silicon Republic.

editorial@siliconrepublic.com