Extremely-thin, spray-applied MXene antennas are prepared for 5G | Now
Spray-applied MXene antennas, developed by Drexel researchers, have proven that they can hold their own against those who run the latest telecommunications equipment.
New antennas so thin that they can be sprayed on are also robust enough to deliver a strong signal at bandwidths used by fifth generation (5G) mobile devices. Performance results for the antennas, which are made from a novel two-dimensional material called MXene, were recently reported by researchers at Drexel University and could have implications for mobile, wearable and connected Internet of Things (IoT) technology.
The MXene antennas that have been in development at Drexel for a little more than two years, already work almost as well as the copper antennas found in most mobile devices on the market today, but with the advantage that they are only a fraction of their thickness and weight.
“This combination of communication performance with extreme thinness, flexibility and durability sets a new standard for antenna technology,” he said Yury Gogotsi, PhD, Distinguished University and Bach Professor of Materials science and engineering at Drexel College for engineers, who is the lead author of a recent article on the MXene antennas published in Advanced Materials magazine. “While copper antennas have been performing at their best for quite some time, their physical limitations have prevented connected and mobile technology from making the big advances that many have predicted. Because of their unique properties, MXene antennas could play an important role in the development of IoT technology. “
While cellular companies are about to adopt 5G technology, which could leverage a less-used portion of the telecommunications spectrum to enable faster data transmission, over time it is likely to become the standard operating area for new technologies.
In addition to achieving high performance, antennas for future devices must also perform well in a variety of environments outside of the circuit boards of phones and computers. This makes MXene an attractive material for new antennas, according to Gogotsi, as it can be sprayed, screen-printed, or ink-jet printed on virtually any substrate and remains flexible without compromising performance.
“In general, copper antenna arrays are made by etching circuit boards. This is a difficult process that can be done on a flexible substrate,” he said Meikang Han, PhD, a postdoctoral fellow at the AJ Drexel Nanomaterials Institute who contributed to the research. “This gives MXene a distinct advantage as it disperses in water and creates an ink that can be sprayed or printed on building walls or flexible substrates to create antennas.”
The Drexel research team manufactured and tested a range of ultra-thin, flexible MXene antennas that can be sprayed onto a variety of surfaces.
In the newspaper, Gogotsi and his staff, including Professor Gary Friedman, PhD, and Kapil Dandekar, PhD, E. Warren Colehower Chair Professor of the Department of Electrical Engineering and Information Technology Drexels College of Engineering reported the performance of three spray-coated MXene antennas that were between 7 and 14 times thinner and 15 to 30 times lighter than a similar copper antenna – even thinner than a paint. They tested the antennas in both laboratory and open environments for key performance metrics of how efficiently the antenna converts power into directional waves – gain, radiation efficiency, and directivity. And they ran the tests on the three radio frequencies commonly used for telecommunications, including one in the target operating frequency for 5G devices.
In each case, the MXene antennas performed within 5% of the copper antennas, with performance increasing with the thickness of the antenna. The most powerful MXene patch antenna, about one-seventh the thickness of standard copper antennas, was 99% as efficient as a copper antenna operated in an open environment at a frequency of 16.4 GHz. MXene were also 98% as effective as their copper counterparts operating in the 5G bandwidth.
Researchers tested the new MXene antennas in open environments and found that their performance was in line with the antennas currently used in telecommunications equipment.
Their performance outperformed several other new materials considered for antennas, including silver ink, carbon nanotubes, and graphene. Significantly, these performance figures did not deteriorate when the MXene antennas were subjected to up to 5,000 bending cycles – a sign of durability that far surpasses the comparison materials.
“MXene’s scalability and environmental sustainability in manufacturing is well established. It is certainly a significant development that this material is now meeting performance targets in line with the best materials on the market today,” said Gogotsi. “As we continue to test different coating patterns and techniques while optimizing the composition of MXene materials, I expect their performance to continue to improve.”
This research was supported by the National Science Foundation, the National Institutes of Health, and Murata Manufacturing, Co. Besides Gogotsi, Friedman, Dandekar and Han, Yuqiao Liu, Roman Rakhmanov and Md Abu Saleh Tajin from Drexel; Christopher Israel and Ahmad Hoorfar from Villanova University and Vladimir Volman, antenna expert at Lockheed Martin Co., contributed to this study.
You can find the full paper here: https://onlinelibrary.wiley.com/doi/10.1002/adma.202003225