A shielding layer can do a lot of jobs badly if you ask too much of it. It can block electromagnetic interference but not neutrons. It can stop radiation but add too much bulk. Lastly, it can survive heat yet fail when bent, stretched, or shaped around real hardware.

That tradeoff has become harder to ignore as spacecraft, medical systems, and advanced electronics move into harsher environments. In the new work, a team at the Korea Institute of Science and Technology, or KIST, says it has built a single material that tackles several of those demands at once. The result is a thin, flexible, 3D-printable composite that can shield both electromagnetic waves and neutron radiation.

The research was led by Dr. Joo Yong-ho at KIST’s Extreme Environment Shielding Materials Research Center. The material combines single-walled carbon nanotubes, known as SWCNTs, with boron nitride nanotubes, or BNNTs, inside a polydimethylsiloxane, or PDMS, polymer matrix.

What makes the design stand out is not just the ingredient list. It is the way the nanotubes assemble.

The researchers found that the two nanotube types behave as complementary partners. Carbon nanotubes conduct electricity well, which helps them reflect and absorb electromagnetic waves. Boron nitride nanotubes, rich in boron, help capture neutrons.

On their own, neither one covers the full problem. Together, the team says, they form a hybrid structure in which the carbon nanotubes wrap around the boron nitride nanotubes. Electron microscopy and elemental mapping supported that core-shell arrangement. In addition, vibrational measurements suggested strain effects caused by the close interaction between the two materials.

That structure matters because it lets one very thin film perform two shielding roles at the same time.

In tests on the “neat” nanotube composite, without the polymer added, the material reached electromagnetic shielding effectiveness above 50 decibels in the X-band range of 8 to 12 gigahertz for SWCNT-rich versions. Even BNNT-rich versions still held shielding levels around 30 decibels. The team also reported a neutron linear attenuation coefficient of about 1.27 mm⁻¹ for a composite with a 2:8 SWCNT to BNNT ratio.

That same sample, only 38.6 micrometers thick, cut neutron intensity by about 4.8%. Scaled to a 1 millimeter film, the researchers said the material would attenuate roughly 72% of incoming neutron radiation.

The paper also says the best electromagnetic shielding came from absorption more than reflection. That matters because absorbed energy is dissipated within the conductive network, rather than simply bounced away at the surface.

The study did not stop at a freestanding nanotube film. The team also built a printable composite by embedding the nanotubes in PDMS, an elastomer better known for flexibility than brute-force shielding.

Using direct ink writing, a form of extrusion-based 3D printing, the researchers produced films and lattices with controlled shapes and sizes. The printing ink stayed stable up to about 100% oscillatory strain. The team said this made it suitable for writing out detailed structures through micron-scale nozzles.

The resulting polymer composite could stretch past 125% strain before fracture, with a Young’s modulus of about 1.72 megapascals. According to the study, those values exceeded those of pristine PDMS, showing that the nanotubes reinforced the soft polymer.

Just as important, the shielding did not collapse when the material was deformed. The polymer composite maintained electromagnetic shielding effectiveness of about 23 decibels during repeated tensile strain cycles up to 40%.

This is where the work starts to look less like a materials demo and more like an engineering platform. A rigid shield can protect a box. A stretchable one can wrap around devices, bend with moving systems, or fit into places where conventional shielding would crack or simply not fit.

One sentence in the paper captures the larger point: geometry matters too.

The researchers printed honeycomb, lattice, and other patterned structures, including freestanding forms and multilayer stacks. Some cylindrical honeycomb lattices reached 30 printed layers. Feature size could be adjusted by changing line spacing, and the printed pieces could be integrated onto microelectronic substrates.

In preliminary observations, honeycomb-patterned composites delivered about 10% to 15% better shielding effectiveness than flat patterns of the same thickness. The team linked that gain to multiple internal reflections inside the patterned structure. In other words, the architecture did not just hold the material, it improved how the material handled incoming electromagnetic waves.

Finite element simulations pointed in the same direction. More complex internal geometries distorted energy flow and increased scattering, which in turn raised energy residence and dissipation inside the structure. The authors were careful here. They said the simulations were meant to capture relative trends, not give a perfect one-to-one match with experiment, because printed parts can vary in feature fidelity, surface roughness, and interlayer contact resistance.

That note is one of the study’s useful limits. Another is that some of the geometry-related gains, including the honeycomb advantage, were described as preliminary and set aside for future work.

Space is the obvious use case in the paper, but it is not the only one. The authors also point to nuclear power systems, neutron- or proton-based medical facilities, particle accelerators, defense systems, wearable protection, and advanced electronics.

The extreme-environment angle runs through the whole study. The neat composite tolerated exposure to 250 degrees Celsius for 12 hours without significant degradation. The polymer composite kept its electromagnetic shielding after one hour in liquid nitrogen and showed a slight increase after reheating at 250 degrees Celsius for one hour. It also stayed intact under direct flame exposure and after rapid freezing, with no cracking or delamination reported.

Dr. Joo said, “This material represents a completely new concept in shielding technology, it is as thin as tape and as flexible as rubber, yet simultaneously blocks both electromagnetic waves and radiation.”

He added, “This technology is significant for securing the advanced materials and establishing the domestic production infrastructure necessary for realizing the space age. We plan to further enhance its performance through structural design optimization and actively pursue its application in actual industrial settings.”

The clearest implication is simpler design. If one thin material can handle both electromagnetic interference and neutron shielding, engineers may not need separate layers that add weight, volume, and assembly complexity.

That matters most in systems where every gram, every millimeter, and every shape constraint counts. Satellites, space stations, reactor equipment, medical devices, and wearable protection all fit that description.

The study also suggests that future shielding may be designed as much by structure as by chemistry. A printable composite that can be tuned into lattices, meshes, or honeycomb forms gives engineers room to tailor protection around specific hardware. This is better than forcing the hardware to adapt to a rigid shield.