Electrical motor uses carbon nanotube yarns for windings

October 04, 2014 - United States Of America

By applying a textile material - carbon nanotube yarn, engineers of LUT have constructed the world's first electrical motor using it as windings.

The electrically conductive carbon nanotube yarn replaces usual copper wires in the windings and the motor prototype has been built by LUT as a start towards lightweight, efficient electric drives.

The output power of the test motor is 40 W, rotates at 15,000 rpm and works almost at 70% efficiency.

“In the near future, carbon nanotube fibers have potential to significantly enhance the performance and energy efficiency of electrical machines. The new technology may revolutionize the whole industry,” LUT said.

The prototype motor uses carbon nanotube yarns spun and converted into an isolated tape by a Japanese-Dutch company Teijin Aramid, which has developed the spinning technology in collaboration with Rice University, the USA.

Researchers are constantly searching for opportunities to upgrade the performance of electrical machines; to this end, one of the objectives is to find higher-conductivity wires for the windings.

The best carbon nanotubes (CNTs) have demonstrated conductivities far beyond those of the best metals.

Thus, future windings made of CNTs may have a double conductivity compared with the present-day copper windings. In order to make CNTs easy to manipulate, they are spun to form multifiber yarn.

Professor Juha Pyrhönen, who led the design of the prototype said, “If we keep the electrical machine design parameters unchanged and only replace copper with future carbon nanotube yarns, it is possible to reduce the Joule losses in the windings to half of the present-day machine losses.”

Pyrhonen added, “Carbon nanotube yarns are significantly lighter than copper and also environmentally friendlier. Therefore, replacing copper with nanotube yarns should significantly reduce the CO2 emissions related to the manufacturing and operating of electrical machines.

“Furthermore, the machine dimensions and masses can be reduced and the motors can also be operated in significantly higher temperatures than the present ones,".

According to Pyrhönen, the electrical machines are so ubiquitous in everyday life that we often forget about their presence. In a single-family house alone there can be tens of electrical machines in various household appliances such as refrigerators, washing machines, hair dryers, and ventilators.

“The industrial applications of the new material are still in their infancy; scaling up the production capacity together with improving the yarn performance will facilitate major steps in the future,”, Business Development Manager Dr. Marcin Otto from Teijin Aramid believes. (AR)