2D material absorbs electromagnetic waves for superior shielding
Electromagnetic interference can be a serious problem for electronic devices, so shielding is usually placed around components. Now, engineers at Drexel University have found that a 2D material called titanium carbonitride is an excellent shielding material, thanks to its ability to absorb rather than reflect electromagnetic waves.
Between such common technologies as radio, television, Wi-Fi, Bluetooth, and cellular phone networks, electromagnetic signals are everywhere. But with the air waves this crowded, electronic devices are exposed to a lot of interference, which can weaken connections, slow down data transfer speeds, and overall impact the function of devices.
To prevent this, engineers build shielding materials into devices, surrounding vital components. These are often thin-film metal foils like copper, which reflect the errant signals back into the air. Although they do the job, these materials can add unwanted bulk to a device.
In the quest for shielding materials with a smaller footprint, the Drexel researchers stumbled upon titanium carbonitride. It belongs to a class of two-dimensional materials called MXenes, which have previously been shown to be useful in making conductive clays, sprayable antennas, and electrodes that could boost battery recharge speeds.
In this case, the team found that sheets of titanium carbonitride, much thinner than human hair, were able to block electromagnetic interference between three and five times better than copper foil.
But the material proved even more useful. The team found that titanium carbonitride actually absorbs the signals rather than reflecting them back out. That means they end up reducing the overall noise in the environment.
"This is a much more sustainable way to handle electromagnetic pollution than simply reflecting waves that can still damage other devices that are not shielded," says Kanit Hantanasirisakul, an author of the study. "We found that most of the waves are absorbed by the layered carbonitride MXene films. It's like the difference between kicking litter out of your way or picking it up — this is ultimately a much better solution.”
Thanks to this absorbing ability and its innate thinness, the team says that titanium carbonitride could be used to wrap components individually in a device, preventing them from interfering with each other even in close proximity.
The research was published in the journal Science.