In response to a examine printed in Superior Composites and Hybrid Supplies, Dr. Dae-Yoon Kim and his workforce on the Korea Institute of Science and Know-how (KIST) Composite Supplies Analysis Institute have been profitable in constructing an electrical motor coil out of solely carbon nanotubes (CNTs) and making it run.
Lightweighting is a prevalent technical issue for future transportation, whether or not within the type of electrical automobiles, drones, or spacecraft. Decreasing a car’s weight saves power and improves battery effectivity and vary. That is thought to be an vital know-how straight associated to sustainability, because it enhances total system efficiency and contributes to carbon emission discount.
Electrical motors, specifically, are a vital element of most electrical mobility automobiles, with coils accounting for a big quantity of the motor’s total weight. Till just lately, metals akin to copper have been utilized as the first materials for coils as a consequence of their excessive electrical conductivity, nevertheless it has been repeatedly famous that they’ve a number of constraints, together with difficulties in acquiring sources, worth volatility, and weight points as a consequence of excessive density.
The scientists experimented with connecting a CNT coil to the motor and found that the motor’s revolutions per minute (RPM) may very well be reliably regulated primarily based on enter voltage. This proves {that a} motor’s important operation, which turns electrical power into mechanical rotating drive, could be carried out while not having steel.
CNTs are one-dimensional tube-shaped nanomaterials containing carbon atoms organized in a hexagonal honeycomb configuration. They’re considerably lighter than peculiar metals and have excellent electrical, mechanical, and thermal conductivity. These options have lengthy piqued curiosity as a next-generation materials, however CNTs have encountered a number of challenges in real-world industrial purposes.
One technical problem is the buildup of catalyst metals employed within the manufacturing course of. These keep as metallic particles on the floor of CNTs, lowering their electrical traits, that are straight linked to motor efficiency. Thus, it’s inconceivable to make use of CNTs in high-performance elements.
The workforce has created a novel CNT purification method utilizing the alignment precept of liquid crystals, a “fourth state of matter” halfway between liquid and stable. The method spontaneously resolves vital aggregation throughout CNT alignment, effectively eliminating metallic particles from the floor.
Most importantly, it could selectively take away pollution with out harming the CNTs’ nanostructure, distinguishing it from different liquid- and gas-phase purification applied sciences. The conductivity of the cleaned CNTs improves considerably, permitting them for use in real electrical motors.
By creating a brand new idea of CNT high-quality know-how that has by no means existed earlier than, we have been capable of maximize {the electrical} efficiency of CNT coils to drive electrical motors with out steel. Primarily based on the innovation of CNT supplies, we’ll take the lead in localizing supplies akin to conductive supplies for batteries, pellicles for semiconductors, and cables for robots.
Dr. Dae-Yoon Kim, Korea Institute of Science and Know-how
The Ministry of Science and ICT (Minister Yoo Sang-im) below the International Younger Join Undertaking (RS-2024-00448639) and Nano Join Undertaking (RS-2024-00450610) of the Nationwide Analysis Basis of Korea supported the examine.
Journal Reference:
Ryu, Ok.-H., et al. (2025) Core-sheath composite electrical cables with extremely conductive self-assembled carbon nanotube wires and versatile macroscale insulating polymers for light-weight, metal-free motors. Superior Composites and Hybrid Supplies. doi.org/10.1007/s42114-025-01302-4.