Instead of relying on thick metals or layers of conductive coatings with limited shielding effectiveness, the researchers relied on layers of two-dimensional titanium carbide, a 2D material only a few atoms thick that conducts like metals and graphite.
The novel nanomaterial, part of the MXene family of 2D transition metal carbides only recently discovered a few years ago, is extremely good at absorbing electromagnetic waves.
In their paper “Electromagnetic Interference Shielding with 2D Transition Metal Carbides (MXenes)” published in the journal Science, the researchers tested samples of MXene films at different thicknesses, from a couple of micrometres up to 45µm. They found that a coating of MXene only 8 micrometres thick could block 99.9999 percent of all radiations in a frequency range from cell phones to radars.
When electromagnetic waves come in contact with MXene, some are reflected from its surface but the majority passes through the surface and then get dissipated within the material’s atomically thin layers, through multiple internal reflections.
The MXene was proven to have a shielding effectiveness beating that of today's copper and aluminium foils.
What's more, the new material retains its shielding effectiveness even when combined with a polymer to make a composite coating. The shielding polymer could either be sprayed as paint, on individual electronic components, removing the need for the shielding cages found in mobile applications.
Alternatively, the compound could be moulded as a whole device enclosure instead of carbon-polymer composites typically used. On a weight basis, it is said to outperform pure copper.
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