From electric cars to drones and satellites, engineers everywhere are chasing one goal: making machines lighter. The lighter the device, the farther it can travel and the longer its battery can last. But there’s a catch—most motors still rely heavily on copper coils. Copper is not only heavy and expensive but also a finite resource.
A Bold Experiment in Korea
Researchers at the Korea Institute of Science and Technology (KIST) decided to push boundaries. They built an electric motor without using a single gram of metal. Instead of copper, the coil was made entirely from carbon nanotubes (CNT). In tests, the motor ran smoothly, responded to voltage changes, and performed its core job—turning electricity into motion.
What Exactly Are Carbon Nanotubes?
Carbon nanotubes are tiny, tube-shaped structures with atoms arranged in a honeycomb pattern. They are incredibly light, stronger than steel, and excellent conductors of heat and electricity. On paper, CNTs seem like the perfect replacement for copper. In practice, however, leftover metallic impurities from the manufacturing process have always interfered with their conductivity.
The Breakthrough
The KIST team developed a clever method using liquid crystals—sometimes called the “fourth state of matter,” existing between a liquid and a solid. These crystals help align the nanotubes while simultaneously stripping away unwanted metal particles. The result is a purified CNT coil that maintains its structure and delivers conductivity suitable for real-world electric motors.
Why It Matters
If scaled for production, this innovation could:
- Reduce the weight of motors and the devices they power.
- Lower dependence on copper and its volatile market prices.
- Open doors for advancements in batteries, semiconductors, and robotics.
Dr. Dae-Yoon Kim of KIST explained it simply: “We’ve shown that motors can run without metals. The next step is adapting this technology for everything from batteries to robotic cables.”
What’s Next?
The next challenge for researchers is to compare CNT-based motors with traditional copper ones in terms of efficiency, heat management, cost, and durability. If the numbers hold up, copper’s long-standing dominance in motor design could soon face serious competition.
