Foldable printed films shield electronics from broadband electromagnetic waves

A group at the Hefei Institutes of Physical Science (HFIPS), part of the Chinese Academy of Sciences, has developed flexible films that block electromagnetic waves across a wide frequency range. The researchers report shielding effectiveness above 100 decibels, and the films survive repeated folding. The manufacturing route can produce them at square-metre scale.

The shielding problem

Electromagnetic waves are now a constant presence in homes, workplaces and public spaces because of the spread of electronic devices and wireless communication. Conventional absorbing and shielding materials tend to work well only if they are thick, and they usually cover a limited band of frequencies. That combination is a poor fit for wearable devices and compact electronics, which need protection that is thin, light and bendable.

The team, led by Professor Ji Shulin at the Institute of Solid State Physics, HFIPS, set out to address both limits at once. Their results appear in two papers, in ACS Applied Materials & Interfaces and in Langmuir, with Qingyang Zeng as first author of both.

Cross-dimensional percolation and printed metastructures

The central design idea is called cross-dimensional percolation. Nanomaterials of different dimensions are combined so that they form a single, three-dimensional interconnected conductive network. In percolation terms, the components touch enough to create continuous pathways through the film.

On top of this network, the researchers added precisely printed conductive patterns known as metastructures. According to the team, these patterns allow the films to regulate electromagnetic waves over a broader band of frequencies than the network would manage alone.

Manufacturing and flexibility

The fabrication process combines three techniques: pressure-assisted filtration, precision inkjet printing and transfer. The group also developed a conductive ink so that the metastructures could be printed accurately.

Flexibility was improved by modifying the surface chemistry of the films. The title of the companion Langmuir paper points to one route: strengthening the interfaces in brittle silver nanowire–MXene composite films by adding the polymers PVA or WPU. Brittleness is a recognised weakness of many highly conductive nanomaterial films, so interface engineering of this kind addresses a practical barrier to folding and bending in use.

What the figures mean

Shielding effectiveness is measured on a logarithmic scale, so 100 decibels corresponds to attenuating transmitted power by a factor of ten billion. The researchers describe this as strong shielding performance. The source material does not give the film thickness, the exact frequency bands tested, the number of folding cycles or the cost of production. These details will matter for anyone judging how the films compare with existing shielding materials.

Why it matters and what comes next

The work is relevant to materials scientists and electronics engineers who are trying to reconcile three demands that usually pull against each other: broadband performance, thinness and mechanical durability. Combining a network-based conductor with printed patterns is a design strategy that others could test with different nanomaterials or pattern geometries. Using inkjet printing and a scalable filtration process also suggests a route towards larger sheets rather than laboratory-sized samples.

The team says the films could support flexible protection for wearable devices and sensitive electronic equipment. The reported performance comes from the researchers’ own measurements, and the source does not describe independent testing or trials in finished devices. Further work would be needed to establish long-term durability, behaviour under real operating conditions and compatibility with commercial manufacturing.

Source: Thin, foldable films offer broadband electromagnetic shielding (Tech Xplore, 6 November 2026).

Image: AI-generated illustration.