Researchers may have created the smallest-ever radio-frequency antennas, a development that should be of interest to any nanotechnology enthusiasts. A group of scientists from Korea published a paper in ACS Nano that details the fabrication of a two-dimensional radio-frequency antenna for wearable applications. Most antennas made from metallic materials like aluminum, cooper, or steel which are too thick to use for nanotechnology applications, even in the wearables space. The newly created antenna instead uses metallic niobium diselenide (NbSe2) to create a monopole patch RF antenna. Even with its sub-micrometer thickness (less than 1/100 the width of a strand of human hair), it functions effectively.
The metallic niobium atoms are sandwiched between two layers of selenium atoms to create the incredibly thin 2D composition. This was accomplished by spray-coating layers of the NbSe2 nanosheets onto a plastic substrate. A 10 mm x 10 mm patch of the material was able to perform with a 70.6% radiation efficiency, propagating RF signals in all directions. Changing the length of the antenna allowed its frequency to be tuned from 2.01-2.80 GHz, which includes the range required for Bluetooth and WiFi connectivity. Within the ever-shrinking realm of sensors for wearable technologies, there is sure to be a place for tiny antennas as well.