Radical New Electric Motor Runs Without Metal Coils

Scientists at the Korea Institute of Science and Technology (KIST) have developed a novel form of wiring that could reshape the design of electric motors and possibly even electric vehicles as a whole. This breakthrough wiring eliminates the need for traditional metals like copper and aluminum, offering a combination of flexibility, conductivity, and extreme lightness.

The innovation lies in a method called Lyotropic Liquid Crystal-Assisted Surface Texturing (LAST). Through this process, researchers created core-sheath composite electric cables (CSCECs) that are not just electrically conductive but incredibly light and bendable. The cables are only about 0.3 mm thick, roughly the width of a business card, but can still handle the demands of powering an electric motorThey’veve already been successfully used in a small CNT-powered electric motor inside a model car.

KIST’s Dr. Dae-Yoon Kim proudly stated: “By developing a new concept of CNT high-quality technology that has never existed before, we were able to maximize the electrical performance of CNT coils to drive electric motors without metal.”

The key to this advancement is the use of lyotropic liquid crystals, which help align the nanotubes that normally clump together, creating a more uniform structure that enhances conductivity. A chemical rinse during the LAST process further purifies the material by removing metal catalyst impurities, crucially maintaining CNTs’ one-dimensional structure.

Thanks to this process, the CNT wiring achieved over 130% increased conductivity, along with long-term stability and significant weight reduction.

In the push for more efficient electric vehicles, weight is a constant enemy. Even though EV motors are already lighter than traditional internal combustion engines, a substantial portion of their mass comes from copper windings. KIST’s innovation challenges that norm.

For example, a Tesla Model S dual-motor setup contains roughly 150 pounds (68 kg) of copper. With CSCEC wiring, that number could drop to about 115 pounds (52.2 kg). While that may seem minor compared to the car’s 4,561-pound (2,069 kg) total weight, the ripple effects are profound. Lighter motors mean quicker throttle response, lower mechanical losses, and less need for cooling systems, which themselves can then be made smaller and lighter, improving overall range and efficiency.

Taking it further, the article speculates that replacing copper in Joby’s electric vertical takeoff and landing (eVTOL) aircraft could cut 300–500 pounds (136–227 kg). That’s not a mere technicality—it’s a game-changer in aviation design, where every pound counts.

Despite its promise, CNT wiring is not without drawbacks. Currently, CNTs still lag behind copper in raw conductivity. Copper clocks in at about 59 megasiemens per meter, while CNTs in this setup achieve around 7.7 MS/m. In practice, this means less current can flow through the same thickness of CNT wire. Case in point: the CNT motor only reached 3,420 RPM, compared to the 18,120 RPM possible with a copper equivalent.

However, due to CNT’s lighter mass, the specific rotational velocity, a useful measure in aerospace and other weight-sensitive fields, was only 6% lower than copper’s. That suggests a near-parity in performance per unit weight, which is a compelling figure.

Another concern is cost. Manufacturing CNT CSCEC cables costs around $375–500 per kilogram, a stark contrast to copper’s modest $10–11 per kilogram. And it’s not as simple as swapping one for the other; integrating CNT wiring would require a complete redesign of motor architecture, insulation methods, and winding configurations.

There’s also the environmental cost. Producing CNTs remains energy-intensive and often involves harsh chemicals. The LAST process, for instance, uses chlorosulfonic acid and generates hydrochloric acid as waste. But is strip mining for copper any better?

It’s a valid question in an era where both performance and sustainability must go hand-in-hand.

Source: Springer Nature Link