Scientists at the Korea Institute of Materials Science have developed an ultra-thin composite film capable of absorbing over 99% of electromagnetic waves across various frequencies, including 5G, 6G, WiFi, and radar for autonomous vehicles, which could significantly enhance the reliability of wireless communication. The findings were published in Advanced Functional Materials.
Electromagnetic waves from electronic components can interfere with nearby devices, reducing performance. To counteract this, electromagnetic shielding materials were developed, most of which reflect over 90% of these waves but only absorb around 10%. Materials with higher absorption levels are generally limited to a single frequency band.
To overcome these limitations, the research team created this composite material, which boasts a reflection rate of less than 1% and absorption of over 99% across three different frequency bands, all within a thickness of less than 0.5 mm. This ultra-thin film is also flexible and durable, retaining its shape even after thousands of folds, making it ideal for rollable phones and wearable devices.
This breakthrough was achieved by modifying the crystalline structure of ferrite, producing a magnetic material with selective absorption properties. The film’s back layer includes a conductive pattern to control wave propagation. By adjusting this pattern’s shape, the material can significantly reduce reflection at specific frequencies. The back layer also features a carbon nanotube film to further enhance its electromagnetic shielding capabilities.
