In a development that reads like nanotechnology’s answer to Roman engineering, a team of South Korean researchers has built ultrathin films that borrow the ancient brick-and-mortar architecture of nacre—and the results are extraordinary. The new hybrid films, described in Advanced Composites and Hybrid Materials, combine carbon nanotube fibers with titanium carbide MXene nanosheets to create a material barely thicker than a human hair that can block more than 92 decibels of electromagnetic interference, hide hot objects from infrared cameras, conduct electricity at nearly the level of metals, and still flex without breaking. The work, led by Minseouk Choi, Kyung Tae Park, Jaewoo Kim, Seon Joon Kim, and Taehoon Kim, spans the Korea Institute of Materials Science, the Korea Institute of Science and Technology, Seoul National University, Korea University, and their affiliated research centers, and it arrives at a moment when the demand for multifunctional shielding materials is accelerating across telecommunications, aerospace, and defense.
The problem the team set out to solve is deceptively simple to state and notoriously difficult to engineer. Modern electronics and military platforms require materials that do several incompatible things at once: they must conduct electricity well enough to reflect and absorb incoming electromagnetic waves across wide frequency bands, they must emit very little infrared radiation so they remain invisible to thermal imaging, and they must survive the mechanical punishment of real-world deployment—bending, vibration, thermal cycling, and moisture. Most materials that excel at one of these tasks fail at another. High-performance metals shield well but are heavy, corrode, and glow brightly in the infrared. Polymer composites can be made flexible but typically sacrifice conductivity, and their shielding effectiveness drops off sharply as films get thinner. Carbon nanotube fibers, which are essentially bundles of nanotubes spun into continuous threads, offer exceptional strength and decent conductivity, but when assembled into films without binding, the individual fibers slide past one another under load, dissipating energy as friction rather than bearing it coherently. That inter-fiber slippage has long been the Achilles heel of CNT fiber assemblies.
The Korean team’s insight was to stop treating the CNT fibers as a fabric to be woven and start treating them as bricks to be mortared together. First, the researchers functionalized the surfaces of the carbon nanotube fibers with amine groups, chemically priming them so that positively charged species could anchor firmly to their surfaces. Then they coated those fibers with Ti₃C₂Tₓ, the most studied of the MXene family—a class of two-dimensional transition metal carbides and nitrides produced by chemically etching away layers from their parent MAX-phase ceramics. MXenes have electrified the materials community over the past decade because they combine metallic-like electrical conductivity with a rich surface chemistry: the Tₓ in the formula denotes terminations such as hydroxyl, oxygen, and fluorine groups that make the nanosheets hydrophilic, dispersible in water, and reactive with amines. In the hybrid film, the Ti₃C₂Tₓ nanosheets play the role of the mortar in a Roman brick wall, infiltrating the spaces between CNT fibers, bonding to their amine-functionalized surfaces, and locking the assembly into a continuous, hierarchical structure.
The elegance of the approach lies in what the mortar does not do. In a conventional composite, a binding matrix often sits between conductive elements and disrupts the percolation pathways that electrons need to travel. Here, the mortar is itself conductive. Because the Ti₃C₂Tₓ nanosheets bridge adjacent CNT fibers, they create efficient two-dimensional conductive networks that run along the film plane, so the very feature that mechanically reinforces the film also electrically unifies it. Load transfer improves for the same reason: stress applied to the film moves from fiber to fiber through the interfacial MXene layer rather than being lost to sliding. The researchers fabricated the films through a simple, scalable assembly process that requires no complex weaving and no post-processing steps, a detail that matters enormously for any technology hoping to leave the laboratory. The result is a continuous film with a thickness of just 17.5 micrometers—roughly one-fifth the diameter of a human hair—whose performance figures rival or exceed those of far bulkier materials.
The numbers are striking. The hybrid film achieves an electrical conductivity of 9,236 siemens per centimeter, placing it among the most conductive carbon-based films ever reported and approaching the range of some metals. Its tensile strength reaches 1.02 gigapascals, a figure comparable to high-strength steel alloys achieved at a fraction of the density. That combination—metallic conductivity and structural robustness in a film thinner than a bacterium is long—is what makes the brick-and-mortar design more than an aesthetic gesture toward nature. Mother-of-pearl, or nacre, owes its legendary toughness to precisely this arrangement: rigid aragonite platelets glued by thin layers of soft biopolymer, a structure that deflects cracks and dissipates energy. The Korean team’s film transposes that biological blueprint into a fully conductive medium, where every interface serves both mechanical and electrical duty simultaneously.
The electromagnetic shielding performance is where the film truly announces itself. Measured across the X-band, the 8 to 12 gigahertz range used by radar, weather satellites, and countless communication links, the 17.5-micrometer film delivers an average shielding effectiveness of 92.8 decibels. Pushing into the Ka-band, spanning roughly 26.5 to 40 gigahertz and increasingly critical for 5G mmWave systems, satellite communications, and automotive radar, the shielding effectiveness rises to an average of 97.4 decibels. To put those numbers in perspective, commercial shielding requirements for consumer electronics are typically set in the 20 to 40 decibel range, and every additional 10 decibels represents a tenfold reduction in transmitted power. A film that attenuates incoming radiation by a factor of several billion while thinner than cling film represents a categorical leap rather than an incremental improvement. The shielding arises from multiple mechanisms working in concert: free electrons in the highly conductive network reflect incoming waves at the film surface, the layered MXene-CNT architecture induces repeated internal reflections between conductive interfaces, and inherent losses in the nanostructure absorb whatever energy penetrates the first barriers.
Equally important is what the film does with heat—in the infrared sense. Every object above absolute zero radiates thermal energy, and mid-wave and long-wave infrared cameras detect that radiation with unnerving sensitivity. The key parameter is emissivity: a perfect blackbody emits at 1.0, polished metals emit near 0.05, and most ordinary materials sit somewhere in between. The Ti₃C₂Tₓ coating on the hybrid film is intrinsically low-emissivity, meaning it radiates far less thermal energy than its surroundings and therefore appears cooler than it actually is to an infrared sensor. In the study, the coated films demonstrated effective infrared stealth performance across a broad temperature range, from room temperature up to 300 degrees Celsius. That operating window covers the thermal regimes of high-power electronics, engine compartments, and hot exhaust-adjacent surfaces, suggesting applications in which equipment must simultaneously manage electromagnetic signature and thermal signature—two of the primary channels by which modern sensors detect and identify targets.
Durability, often the forgotten variable in headline-grabbing materials papers, received careful attention. The researchers subjected the hybrid films to diverse environmental conditions and found that the film maintains long-term stability of its tensile strength, electrical conductivity, and electromagnetic shielding effectiveness. This resilience traces back to the chemistry of the interfaces: the amine-functionalized CNT surfaces bond robustly to the MXene nanosheets, and the dense, mortar-filled architecture limits the pathways by which moisture, oxygen, and thermal cycling would normally degrade conductive networks. For a material intended to line aircraft skins, wrap cables, or encase satellites that will endure years of thermal swings between sunlight and shadow, that endurance is not a footnote—it is the difference between a laboratory curiosity and a deployable technology.
The fabrication scalability deserves its own emphasis. Many record-setting nanomaterials are produced in milligram quantities by processes that cannot be industrialized. The assembly strategy reported here builds the film from continuous CNT fibers coated in aqueous MXene dispersion, avoiding both intricate weaving operations and post-processing treatments. The researchers describe the approach as a strategic design for multifunctional shielding materials and frame it as a viable path toward next-generation stealth and communication technologies. Because the film is conformal—thin enough and flexible enough to coat curved and irregular surfaces—it could be integrated into radomes, antenna housings, wearable electronics, drone skins, and the interiors of increasingly crowded electromagnetic environments such as electric vehicles, where dozens of high-frequency systems operate side by side and interference between them is a genuine engineering crisis.
The broader significance of the work lies in its demonstration that architectural design and chemical design can be fused to solve the classic trade-off problem in multifunctional materials. The brick-and-mortar concept resolves the tension between strength and conductivity that has constrained carbon-based films, and the intrinsic low emissivity of MXene resolves the tension between shielding and stealth. Funding for the research came from South Korea’s Nano & Material Technology Development Program through the National Research Foundation of Korea, supported by the Ministry of Science and ICT, along with a National Research Council of Science & Technology grant, signaling that the strategic importance of electromagnetic and thermal signature management is recognized at the national policy level. As 6G networks, dense satellite constellations, and sensor-rich autonomous platforms come online, the electromagnetic spectrum is becoming as contested a space as any physical terrain. Materials like this MXene-mortared CNT film—one that reflects, absorbs, hides, and carries load all at once—may become the quiet workhorses of that crowded future, invisible to radar eyes and infrared cameras alike, while keeping the signals of the machines they protect clean and intact.
Subject of Research: Multifunctional Ti₃C₂Tₓ MXene/carbon nanotube fiber hybrid films with brick-and-mortar architecture for electromagnetic interference shielding and infrared stealth
Subject of Research: Technology and Engineering
Article Title: MXene as conductive mortar: Assembly of Ti₃C₂Tₓ and carbon nanotube fibers into multifunctional films for EMI shielding and infrared stealth
Article References: Choi, M., Park, K. T., Lim, D. J., Kim, S. H., Yang, H. S., Kim, J., Jang, J., Lee, K., Jung, Y., Jang, H., Kim, J., Kim, S. J., & Kim, T. (2026). MXene as conductive mortar: Assembly of Ti3C2Tx and carbon nanotube fibers into multifunctional films for EMI shielding and infrared stealth. Advanced Composites and Hybrid Materials. https://doi.org/10.1007/s42114-026-02009-w
Image Credits: AI Generated
DOI: 10.1007/s42114-026-02009-w
Keywords: CNT fiber, MXene, brick-and-mortar structure, electrical conductivity, mechanical robustness, electromagnetic interference shielding, infrared stealth, low emissivity, hybrid film, Ti₃C₂Tₓ, X-band, Ka-band
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Denise Maddox. (September 10, 2026). MXene-carbon nanotube films enable EMI shielding and infrared stealth. Scienmag. https://scienmag.com/mxene-carbon-nanotube-films-enable-emi-shielding-and-infrared-stealth/
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