# Carbon Nanotube Fibers as “Bricks” and MXene Nanosheets as “Cement” Enable an Ultrathin Composite with EMI Shielding, Infrared Stealth, and High Mechanical Strength
# At Just One-Fifth the Thickness of a Human Hair, the Film Blocks More Than 99.9999999% of Electromagnetic Waves, with Potential Applications Ranging from Defense and Aerospace to 5G/6G and Wearable Electronics
CHANGWON, South Korea — A research team led by Dr. Taehoon Kim of the Composites & Convergence Materials Research Division at the Korea Institute of Materials Science (KIMS) , headed by President Chul-jin Choi, has collaborated with research teams led by Dr. Seon Joon Kim and Dr. Jaewoo Kim of the Korea Institute of Science and Technology (KIST) to develop an ultrathin composite film that combines electromagnetic interference (EMI) shielding, infrared (IR) stealth, and high mechanical strength. The researchers achieved these multifunctional properties by combining carbon nanotube (CNT) fibers and MXene in a structure resembling “bricks and mortar.” The technology is expected to protect military systems and aerospace electronics while also reducing electromagnetic interference in 5G/6G communication devices and wearable electronics.
As modern defense systems and advanced electronic devices continue to evolve, demand is increasing for lightweight and flexible shielding materials capable of simultaneously protecting against infrared detection and electromagnetic threats . Conventional metallic shielding materials are heavy, susceptible to corrosion, and limited in flexibility . Carbon nanotube fibers offer an attractive alternative because they are lightweight, mechanically strong, and highly effective at EMI shielding. However, their fiber-like form makes them difficult to assemble into large-area films, and they exhibit relatively high infrared emissivity . MXene , meanwhile, has low infrared emissivity and is therefore promising for stealth applications, but its relatively poor mechanical strength and long-term stability have limited its practical use . This has created a need for a material that can simultaneously provide EMI shielding, infrared stealth, and robust mechanical properties.
To address these limitations, the research team developed an ultrathin hybrid composite film by combining CNT fibers with MXene. To effectively integrate the advantages of the two materials, the researchers drew inspiration from the “brick-and-mortar” architecture found in construction . The surfaces of the CNT fibers were first functionalized with amine groups to promote bonding with MXene. The fibers were then continuously passed through a MXene solution and wound side by side to form a film. In the resulting hybrid architecture, aligned CNT fibers function as the structural “bricks,” while MXene fills the spaces between them and acts as electrically conductive “mortar.”
This structure suppresses slippage between individual CNT fibers, thereby increasing the mechanical strength of the film. At the same time, it creates continuous electrical pathways throughout the material, significantly improving its electromagnetic shielding performance. The MXene coating on the film surface also reduces infrared emission, lowering the material’s visibility to infrared detection systems such as thermal imaging cameras.
Despite being only 17.5 micrometers thick— approximately one-fifth the thickness of a human hair —the developed film achieved an EMI shielding effectiveness of approximately 90 decibels (dB), blocking more than 99.9999999% of incident electromagnetic waves in communication and radar frequency bands. The film also exhibited a tensile strength of 1.02 gigapascals (GPa), demonstrating mechanical performance comparable to that of high-strength steel . At the same time, it effectively suppressed infrared emission and maintained stable performance under high-temperature, high-humidity conditions and repeated mechanical deformation compared with conventional MXene films.
Because the new film is thin and lightweight while simultaneously providing EMI shielding and infrared stealth, it could be used to improve the survivability of defense systems such as fighter aircraft, unmanned aerial vehicles, and drones, as well as to protect aerospace electronic equipment. Its flexible film form also makes it suitable as an EMI shielding material for 5G and 6G communication devices, wearable electronics, and next-generation foldable or bendable electronic products.
Another major advantage of the technology is its compatibility with a continuous fabrication process, providing a pathway toward future large-area production. The research team is currently filing patents for the core technology and plans to continue follow-up research focusing on large-area film fabrication and integration into actual components. In addition, two technology transfers are currently underway for the CNT fiber production technology that serves as one of the core enabling technologies behind the research.
“The key to this technology is combining nanomaterials with different characteristics like bricks and mortar, preserving the strengths of each material while compensating for their respective weaknesses,” said Dr. Taehoon Kim, the lead researcher at KIMS. “We expect this multifunctional material to find broad applications not only in future defense systems and aerospace technologies but also in addressing electromagnetic interference issues in next-generation communication devices and wearable electronics,” he added.
The research was supported by the Convergence Research Group Program of the National Research Council of Science & Technology (NST), through the Convergence Research Center for Solutions to Electromagnetic Interference in Future Mobility, and by the National Strategic Technology Materials Development Program of the National Research Foundation of Korea (NRF). The findings were published online on August 5, 2026, in Advanced Composites and Hybrid Materials (Impact Factor: 15.5), an international journal in the field of composite materials. The paper is titled “MXene as Conductive Mortar: Assembly of Ti₃C₂Tₓ and Carbon Nanotube Fibers into Multifunctional Films for EMI Shielding and Infrared Stealth.”
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About Korea Institute of Materials Science(KIMS)
KIMS is a non-profit government-funded research institute under the Ministry of Science and ICT of the Republic of Korea. As the only institute specializing in comprehensive materials technologies in Korea, KIMS has contributed to Korean industry by carrying out a wide range of activities related to materials science including R&D, inspection, testing&evaluation, and technology support.
Advanced Composites and Hybrid Materials
MXene as conductive mortar: Assembly of Ti3C2Tx and carbon nanotube fibers into multifunctional films for EMI shielding and infrared stealth
5-Aug-2026