A research group headed by Dr. Sang-Bok Lee and Byeongjin Park from the Department of Functional Composites at the Korea Institute of Materials Science (KIMS) has successfully developed the world’s first ultra-thin composite film.
This film absorbs more than 90% of electromagnetic waves used in 5G communication instead of reflecting them. For 5G communication frequencies above 26 GHz, the novel technology can solve the secondary electromagnetic interference problem. KIMS is a government-funded research institute under the Ministry of Science and ICT.
Electromagnetic noise generated by electronic components interrupts and degrades the performance of other electronic systems. To avoid this, uninterested electromagnetic noise from the components is blocked by shielding material. Existing reflection-dominant shielding materials such as metal and carbon, which are highly conductive, reflect more than 90% of electromagnetic waves, resulting in an absorption rate of less than 10%.
5G communication uses frequencies greater than 26 GHz, which is 10 times higher than the existing 3G/4G frequencies. As secondary electromagnetic noise interference is more severe at high frequencies and short wavelengths, shielding materials with high absorbing capability are in high demand.
The magnetic material and polymer-mixed composite film with conductive fibers sewed in a grid shape developed by the research team is an absorption-dominant shielding material that surprisingly absorbs electromagnetic waves at 5G communication frequencies. This material absorbs more than 90% of electromagnetic waves and reflects less than 1% of the waves.
Furthermore, because this material is thin and flexible, its performance did not deteriorate when wrinkled or folded.
Smartphones that use 5G/6G communication, automotive radars, base stations (small cells) and low-orbit communication satellite antennas can all benefit from absorption-dominant electromagnetic wave shielding material technology.
Only two or three companies in the United States, Japan and Germany were able to commercialize the technology because these materials require cutting-edge material design technologies to achieve advanced performance in the 5G/6G frequency bands.
The material we developed uses a conductive grid to present a new concept of an ultra-thin material that absorbs most of the electromagnetic waves without reflecting them. If the technology is applied to wireless communication devices such as smartphones, as well as to automotive radars, the reliability of autonomous driving will be greatly improved.
Sang-Bok Lee, Principal Researcher, Department of Functional Composites, Korea Institute of Materials Science
The study was funded by the Ministry of Science and ICT, and the research was carried out as the fundamental research project of KIMS, “Magnetic based Pseudo-materials Absorbing Extremely High Frequency (EHF) Electromagnetic Waves” and the project of the Korea Materials Research Center, “Development of mmWave absorbing/shielding and heat-dissipation properties tailored composites.”
The study was published on February 28th, 2022, in the Journal of Materials Chemistry A, a renowned academic journal in the field of materials science published by the Royal Society of Chemistry.
The research team is in talks with several companies about transferring technology for the mass manufacturing of absorption shielding material. They are also performing extensive research into how the material can be used in ADAS radar systems.
Ryu, S. H., et al. (2022) Electromagnetic wave shielding flexible films with near-zero reflection in the 5G frequency band. Journal of Materials Chemistry A. doi.org/10.1039/D1TA10065C.