Magnetic nanoparticles could cut adhesive curing from 24 hours to one, study finds

Nanyang Technological University (NTU) and automotive supplier Motherson are working to adapt a magnetic curing method called Spinheat for factory use, according to an NTU news release. NTU said one-hour magnetic curing produced adhesive joints with bonding strength comparable to a 24-hour oven cure.

Curing is the step that hardens paints, adhesives and resins. Spinheat mixes magnetic nanoparticles into the material. When an alternating magnetic field, one that rapidly reverses direction, passes through, the particles heat the material from inside, so the whole component doesn’t need to sit in an oven, the release said.

NTU’s research is led by professor Raju V. Ramanujan and associate professor Terry Steele, both in the School of Materials Science and Engineering. The latest version of Spinheat adjusts the magnetic field using real-time temperature feedback, the release said. Motherson will help test it under conditions closer to industrial production.

Feedback control during curing

NTU first showed epoxy curing with a magnetic field in 2020 with its magnetocuring glue, according to the release. The latest research appeared in Applied Materials Today. In a separate experiment, the authors mixed doped ferrite magnetic nanoparticles into a thermoset epoxy resin, a plastic that hardens permanently, and heated it with the field. A microprocessor adjusted the field strength as temperatures changed, the paper said. The release said the approach could also prevent heat damage to other parts of a component, particularly those made of heat-sensitive materials.

Epoxy curing releases its own heat, and that heat can run away. The abstract said feedback-controlled heating prevented that runaway and reduced voids, or gas pockets, from 33.0 percent to 5.3 percent of the volume, as measured by nano-computed tomography, a 3D X-ray imaging method.

The authors' preprint, an earlier version posted online on SSRN, also said the samples reached their target temperatures within 180 seconds.

Motherson, which the release said supports customers from mote than 475 facilities across 47 countries, brings automotive engineering and manufacturing capabilities to the collaboration.

Limits and next steps

The results come from laboratory samples. The published paper reported lap shear strength, a measure of how well a joint resists sliding forces, of 7.2 megapascals for the one-hour magnetic cure and 7.3 megapascals for the 24-hour oven cure, with uncertainties of 1.4 and 2.2 megapascals. Those ranges overlap, so the strengths are comparable, not proven identical. The release gives no measured energy savings, so its energy and emissions benefits are projections.

Steele said the next challenge is to understand "how this can work reliably within automotive manufacturing." The researchers are still seeking to test Spinheat closer to factory conditions, particularly for paints and coatings, and will study coating thickness, curing speed, temperature control and component sizes and shapes.

Other groups are also targeting cure time, including Toray CMA, which says its fast-cure composite cuts curing by up to 45 percent. NTU is exploring commercialization, including start-up options, and filed intellectual property through NTUitive, its innovation company. The paper appeared in the April 2026 issue of Applied Materials Today.