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Scientists in South Korea have developed an ultrathin composite film that can block 99.9999999 percent of incoming electromagnetic waves while also reducing infrared emissions. The material could have applications ranging from stealth aircraft and drones to smartphones and other compact electronic devices.

The film is only 17.5 micrometers thick, making it thinner than a human hair. Researchers from the Korea Institute of Materials Science and the Korea Institute of Science and Technology created it by combining carbon nanotube fibers with MXene, two nanomaterials whose individual limitations had previously restricted their usefulness.

The researchers used an approach inspired by brick-and-mortar construction. Carbon nanotube fibers form the structural framework, while MXene nanosheets occupy the microscopic spaces between them. The team chemically treated the surfaces of the nanotubes with amine groups, allowing them to form stronger molecular bonds with the MXene.

This arrangement addresses several weaknesses found in the individual materials. Carbon nanotubes are lightweight, electrically conductive and mechanically strong, but they can be difficult to assemble into uniform films and can produce strong infrared emissions. MXene, meanwhile, is effective at absorbing infrared radiation but is relatively fragile and vulnerable to environmental degradation.

The resulting composite reportedly provides approximately 90 decibels of electromagnetic shielding, blocking more than 99.9999999 percent of electromagnetic waves in radar and communication frequency bands. It also has a tensile strength of about 1.02 gigapascals, while maintaining flexibility that allows the film to bend, fold and twist without losing its conductive pathways.

Another notable property is its extremely low infrared emissivity. By suppressing thermal radiation, the material could reduce the visibility of objects to infrared sensing systems. Its resistance to heat and moisture is also intended to address the environmental stability problems associated with pure MXene.

The combination could eventually have implications for aerospace and defense applications. If adapted for practical use, lightweight electromagnetic and infrared shielding could potentially be incorporated into aircraft, drones and other platforms without the weight and rigidity associated with conventional metal shielding.

The researchers also see civilian applications. The film could potentially be used inside smartphones, wearables, foldable devices and other electronics to limit electromagnetic interference as wireless technologies become increasingly complex.

Further development and real-world testing will be needed to determine how effectively the material can transition from laboratory demonstrations to commercial and aerospace applications.