The breakthrough, say the researchers, could make installing an antenna for next-generation flexible electronics "as easy as applying some bug spray." The key is the use of a new family of atomically thin 2D metal inorganic compounds - called "MXenes" - that have unique properties compared to conventional three-dimensional materials.
Graphene - which comprises just a single layer of carbon - is probably the most well-known 2D material, however it is limited to carbon in its composition. The new family of materials includes 2D early transition metal carbides, nitride, and carbonitrides. An MXene titanium carbide material was used in the Drexel research.
"This is a very exciting finding because there is a lot of potential for this type of technology," says Kapil Dandekar, PhD, a professor of Electrical and Computer Engineering in the College of Engineering, who directs the Drexel Wireless Systems Lab, and was a co-author of the research. "The ability to spray an antenna on a flexible substrate or make it optically transparent means that we could have a lot of new places to set up networks — there are new applications and new ways of collecting data that we can’t even imagine at the moment."
The MXene titanium carbide used by the researchers can be dissolved in water to create an ink or paint. Its exceptional conductivity, say the researchers, enables it to transmit and direct radio waves, even when it's applied in a very thin coating.
"We found that even transparent antennas with thicknesses of tens of nanometers were able to communicate efficiently," says Asia Sarycheva, a doctoral candidate in the A.J. Drexel Nanomaterials Institute and Materials Science and Engineering Department. "By increasing the thickness up to eight microns, the performance of MXene antenna achieved 98 percent of its predicted maximum value."
Such ultra-thin antennas, say the researchers, would be able to be easily embedded - literally, sprayed on - in a wide variety of objects