How many times have you heard about electric cars that weigh too much? Well, that nonsense is about to end. In Korea they just invented electric motors that work without a gram of metal. No copper, no aluminum, just carbon nanotubes that weigh as much as a sheet of paper but conduct electricity better than your old stereo. The trick? A technology called LAST. And if you think this is lab stuff, they've already got a toy car rolling. The next step? Feather-light electric motors.
Carbon Nanotubes Breakthrough in Electric Motors
The researchers of Korea Institute of Science and Technology (KIST) have developed something that seemed impossible: electrical cables made entirely of carbon nanotubes. These revolutionary materials They are not an absolute novelty, but the way they have transformed them into practical conductors is really interesting. Dr. Dae-Yoon Kim and his team created what they call CSCEC (Core-Sheath Composite Electric Cables): cables just 0,3 millimeters thick that completely replace the copper in electric motor coils.
The crux is a process called Lyotropic Liquid Crystal-Assisted Surface Texturing (LAST). Think of liquid crystals as microscopic conductors that align carbon nanotubes into perfect formations. This process not only improves conductivity by 130%, but also eliminates metallic impurities that usually compromise performance. The result? Cables that conduct electricity while maintaining a ridiculously low weight.
How LAST Technology for Electric Motors Works
LAST technology is the beating heart of this innovation. Carbon nanotubes, normally tangled like microscopic spaghetti, are “disciplined” using Lithotopic liquid crystals. These crystals have a unique property: they flow like liquids but maintain a directional order like solid crystals. When the nanotubes pass through this ordered environment, they align perfectly and separate into linear structures ideal for electrical conduction.
The process also includes a chemical wash that removes the metal catalysts used during the production of the nanotubes. This step is crucial because Metallic impurities can compromise long-term electrical performance. The end result is CSCEC cables with a 256 micrometer conducting core surrounded by an “insulating sheath” just 10 micrometers thick.
The KIST team has already demonstrated the feasibility by building a small electric motor that powers a toy car. This engine is completely metal free. and it works perfectly, although with reduced performance compared to copper equivalents.
The nanotube engine reaches 3.420 rpm versus 18.120 for the copper one, but the weight-performance ratio is extraordinarily favorable.
The impact on electric vehicles of the future
The implications for the auto industry are potentially enormous. Consider how much copper the coils contain, for example, a Tesla Model S engine. By replacing copper with CSCEC nanotubes, the weight of the engines could drop from 68 kg to around 52 kg. It may seem like little, but in an electric vehicle every kilogram counts for autonomy and efficiency.
Why? Well, because weight reduction has a knock-on effect: less rotating mass means faster acceleration, better throttle response, and lower mechanical losses. The cooling system can be sized smaller because the nanotubes generate less heat. As we have highlighted, the industry is desperately seeking alternatives to rare earths and traditional metals.
Economic challenges and future prospects for electric motors
Of course, as always, not everything is rosy. The electrical conductivity of CSCEC nanotubes remains lower than that of copper: 7,7 megasiemens per meter versus 59 for copper. This means that for the same size, nanotube motors deliver less power. However, the performance-to-weight ratio is competitive, especially in applications where every gram counts, such as aerospace and drones.
At the moment, cost is the main obstacle: producing CSCEC nanotubes costs between $375 and $500 per kilogram, compared to $10-11 for copper. But researchers are optimistic: optimizations in production and improvements in alignment techniques could dramatically reduce costs in the coming years.
The metal-free electric future
This discovery is another small, crucial turning point in the design of electric motors. As already seen in other innovations, the automotive industry is exploring alternative ways to overcome current limitations. Carbon nanotubes could be the key to lighter, more efficient electric vehicles that are independent of rare earth supplies.
The research published on Springer Nature Link opens up fascinating scenarios: drones with greater autonomy, more agile electric cars, and perhaps one day entire transportation systems free from dependence on traditional metals. The future of electric motors could really be written in carbon, not copper.
