KIST Powers a Metal-Free Motor Revolution with CNT Coil Technology
In the relentless race towards cleaner, smarter transportation, every gram matters. The lighter the vehicle, the more miles it can squeeze out of a battery charge. And now, a Korean research team has taken a radical step that could tip the scales in favour of efficiency by developing a motor coil made entirely without metal. Yes, you read that right – no copper, no aluminium, just carbon nanotubes.
This could well be the turning point the electrified transport sector has been waiting for.
Why lightweighting matters in mobility
From electric scooters zipping through city centres to satellites orbiting the planet, cutting weight is more than a nice-to-have – it’s a necessity. Reducing mass directly reduces energy consumption. Less energy spent means better battery efficiency, and better efficiency leads to extended operational range. It’s a domino effect that hits sustainability targets hard.
At the heart of nearly every electric vehicle is a motor. And central to those motors? Coils. Traditionally, copper coils have been king due to their superb conductivity. But copper is heavy, expensive, and increasingly tricky to source. Supply chain volatility, price spikes, and environmental pressures have cast a long shadow over copper’s long-standing reign.
Carbon nanotubes
Enter carbon nanotubes, or CNTs for short. These tiny, one-dimensional structures are essentially rolled-up sheets of graphene, boasting a honeycomb of carbon atoms arranged with atomic precision. Despite their microscopic size, they pack a serious punch: high electrical and thermal conductivity, incredible tensile strength, and a featherweight profile.
CNTs have been science’s darling for decades, hyped as the material of the future. Yet, for all their promise, real-world applications have been rare. The trouble? Manufacturing CNTs at scale while maintaining their purity and performance.
KIST’s ground-breaking achievement
That’s where the Korea Institute of Science and Technology (KIST) steps in. Led by Dr. Dae-Yoon Kim, researchers at KIST’s Composite Materials Research Institute have pulled off what was long considered unfeasible: they’ve built an electric motor coil using only carbon nanotubes, completely sidestepping metal. Not only did they make it, they made it work.
Their CNT-based coil demonstrated stable revolutions per minute (RPM) control, responding predictably to input voltage. In plain terms, it functioned just like a regular motor coil – only without the metal.
Dr. Kim explained the significance: “By developing a new concept of CNT high-quality technology that has never existed before, we were able to maximise the electrical performance of CNT coils to drive electric motors without metal.”
The purification puzzle
One major hurdle in using CNTs industrially is purification. During their manufacture, catalyst metals often cling to the surface of the nanotubes, impairing their electrical properties. That’s a deal-breaker for precision components like motor coils.
KIST’s team tackled this challenge head-on with an inventive purification process inspired by the physics of liquid crystals – the mysterious ‘fourth state’ of matter that exists between solid and liquid. By leveraging liquid crystal alignment behaviour, the researchers managed to cleanse CNTs of metallic residues without damaging their delicate structure.
The result? Purified CNTs with dramatically improved conductivity, finally up to snuff for real-world electric motors.
What is CNT-based coil technology, and why is it revolutionary?
To appreciate what KIST has done, it’s worth breaking down what a coil does and why CNTs matter so much.
Electric motor coils generate magnetic fields when current flows through them. These magnetic fields, in turn, produce torque to spin the motor. Conductivity is crucial here – the more conductive the material, the better the motor’s performance.
Traditionally, copper has been the go-to material because of its unmatched conductivity among non-precious metals. But at nearly nine grams per cubic centimetre, it’s a heavyweight. Carbon nanotubes, by comparison, are around 1.3 to 1.4 grams per cubic centimetre. That’s nearly seven times lighter.
Moreover, CNTs are flexible, corrosion-resistant, and can withstand high temperatures. So not only are they lighter, they’re tougher in the long run. Imagine motors that don’t degrade as quickly under stress, or that don’t require as much shielding or cooling. The implications ripple across automotive, aerospace, and robotics industries.
Steel who? The end of metal coils?
So, are we witnessing the death knell of metal-based motor coils? Not quite yet – copper still holds the crown for commercial applications, largely because it’s cheap, familiar, and comes with an established supply chain. But the winds are shifting.
CNT-based coils could open doors to ultra-light electric aircraft, micro-drones with longer flight times, or electric cars that get more distance from the same battery pack. They might even find a home in wearables, biomedical devices, or flexible electronics.
Dr. Kim put it succinctly: “Based on the innovation of CNT materials, we will take the lead in localising materials such as conductive materials for batteries, pellicles for semiconductors, and cables for robots.”
Backed by science, fuelled by purpose
This leap in CNT purification and application didn’t happen in a vacuum. It was supported by South Korea’s Ministry of Science and ICT, specifically through the Global Young Connect and Nano Connect projects (RS-2024-00448639 and RS-2024-00450610, respectively).
The findings were recently published in the international journal Advanced Composites and Hybrid Materials, which boasts an impressive impact factor of 23.2. It’s no small feat to be featured there, underscoring just how ground-breaking this development really is.
And let’s not forget KIST’s pedigree. Established in 1966, it was Korea’s first government-funded research institute, tasked with advancing national scientific capability. Today, it’s a hotbed of innovation aimed squarely at solving some of the world’s most pressing industrial and societal challenges.
A lighter, smarter future
As we move into an era where electrification dominates mobility, the demand for lighter, more efficient components will only intensify. KIST’s CNT-based motor coil is more than a technical triumph; it’s a glimpse into what comes next.
From reducing dependency on scarce metals to supercharging the next generation of transport tech, this development could shift the paradigm. For manufacturers, engineers, and investors alike, it signals a new material horizon worth exploring – and fast.
