Based on a examine printed in Superior Composites and Hybrid Supplies, Dr. Dae-Yoon Kim and his group on the Korea Institute of Science and Expertise (KIST) Composite Supplies Analysis Institute have been profitable in constructing an electrical motor coil out of solely carbon nanotubes (CNTs) and making it run.
KIST has developed a expertise for producing high-quality CNTs by using the liquid crystal state, sometimes called the “fourth state of matter”, distinct from solids, liquids and gases. This expertise dramatically improves {the electrical} conductivity of CNT coils, permitting them to drive electrical motors with out the necessity for copper coils. Picture Credit score: Korea Institute of Science and Expertise (KIST)
Lightweighting is a prevalent technical problem for future transportation, whether or not within the type of electrical automobiles, drones, or spacecraft. Lowering a automobile’s weight saves power and improves battery effectivity and vary. That is thought to be an essential expertise straight associated to sustainability, because it enhances total system efficiency and contributes to carbon emission discount.
Electrical motors, particularly, are a vital part of most electrical mobility automobiles, with coils accounting for a big quantity of the motor’s total weight. Till lately, metals akin to copper have been utilized as the first materials for coils as a consequence of their excessive electrical conductivity, but it surely has been repeatedly famous that they’ve a number of constraints, together with difficulties in acquiring sources, value 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 based mostly on enter voltage. This proves {that a} motor’s important operation, which turns electrical power into mechanical rotating pressure, will be carried out while not having metallic.
CNTs are one-dimensional tube-shaped nanomaterials containing carbon atoms organized in a hexagonal honeycomb configuration. They’re considerably lighter than bizarre 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 functions.
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 not possible to make use of CNTs in high-performance parts.
The group has created a novel CNT purification method utilizing the alignment precept of liquid crystals, a “fourth state of matter” halfway between liquid and strong. 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 growing a brand new idea of CNT high-quality expertise 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 metallic. Primarily based on the innovation of CNT supplies, we are going to 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 Expertise
The Ministry of Science and ICT (Minister Yoo Sang-im) underneath the International Younger Join Venture (RS-2024-00448639) and Nano Join Venture (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.
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