New Carbon Nanotube Coating Could Supercharge 6G Technology

Ultrathin nanotube films absorb terahertz waves, boosting 6G performance and enabling advanced shielding and medical applications.

Researchers at Skoltech, working with colleagues from KTH Royal Institute of Technology in Sweden, have developed a key technology that could support future 6G communications and enable faster wireless data transfer.

Instead of a traditional device component, the innovation is a carbon nanotube-based coating that acts like a highly absorbent black paint, blocking electromagnetic radiation where it would interfere with performance. The findings were published in an open-access study in Nature Communications.

Terahertz radiation sits between infrared light, used in night vision, and microwaves, which heat food. This region of the electromagnetic spectrum is considered highly promising for 6G networks, as well as for advanced imaging and sensing applications in medicine and technology.

“The ultrathin single-walled carbon nanotube films we synthesized for this study are similar to those we used previously to create small-scale components such as lenses and antennas. This time it’s not about standalone components. Instead, we show how that same carbon-based material can be leveraged to control electromagnetic radiation in 2D integrated optical circuits, eliminate interference, and enable additional functionality,” said study co-author Associate Professor Dmitry Krasnikov of Skoltech Photonics.

Carbon Nanotube Coating for Terahertz Waveguides

The coating is applied using aerosol chemical vapor deposition and works by absorbing terahertz radiation, preventing it from spreading in unwanted directions. This is especially useful for insulating silicon waveguides, which carry electromagnetic signals between components inside a device. By keeping signals confined within the waveguide, the coating also acts as a barrier against outside interference. The thickest versions of the coating showed record levels of absorption.

To test its performance, the researchers examined films with thicknesses ranging from 2 to 53 nanometers. Near the upper end of this range, the films were so effective that even highly sensitive instruments detected almost no remaining signal.

“We have shown that ultrathin coatings based on carbon nanotubes can serve as an effective tool for controlling terahertz radiation. They can be synthesized rapidly and are easily integrated into photonic circuits, making this technology promising for the development of new generations of terahertz devices—from 6G communication systems to sensing and medical technologies,” the director of Skoltech Photonics and study co-author Professor Albert Nasibulin summed up.

Applications Beyond 6G: Shielding and Medical Uses

Professor Dmitry Lioubtchenko of KTH Royal Institute of Technology, also a co-author, highlighted additional uses beyond telecommunications. “Electromagnetic shielding can be used to insulate a room or building from telecommunication signals, only allowing electromagnetic radiation of specific wavelengths to pass through. This is relevant for the design of prisons, among other places. Also, considering the prospects of terahertz radiation use in medicine as a safer but probably not entirely harmless alternative to X-rays, we will increasingly need ways to manipulate terahertz waves to confine the body’s exposure to a narrow region that is being examined and protect medical personnel.”

Reference: “Ultrathin Single-Walled Carbon Nanotube Surface Wave Absorbers for Terahertz Dielectric Waveguides” by Nikolaos Xenidis, Mehrdad Rezaei Golghand, Nikita I. Raginov, Joachim Oberhammer, Dmitry V. Krasnikov, Albert G. Nasibulin and Dmitry V. Lioubtchenko, 2 December 2025, Nature Communications.
DOI: 10.1038/s41467-025-66559-1

Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.