|Printable antennas may bring low cost and flexibility to a range of applications|
Researchers from the University of Manchester have used compressed graphene ink to print an RF antenna measuring 14cm x 3.5mm onto a piece of paper. According to the team, the antenna performed well enough to make it practical for use in RFID tags and wireless sensors.
Graphene ink is usually made by mixing graphene flakes with a solvent, and sometimes a binder. Graphene ink with binders usually conducts electricity better, but only after the binder – an insulator – is broken down by annealing. But this high temperature process limits the surfaces onto which graphene ink can be printed.
The team found that by printing and drying the ink, then compressing it with a roller, graphene’s conductivity was increased by more than 50 times.
Researcher Dr Zhirun Hu said: “What makes printed graphene attractive for antenna applications is its ultra low cost and flexibility and the fact that it can be printed on any substrate without needing a high temperature process. We can use screen printing to produce graphene antennas, which suits low cost mass production.”
Expanding, Dr Hu noted: “Being able to print antennas on any substrate means we could see a disruptive technology for low cost, wearable communications products. In addition, we’ll be able to print a complete RF transceiver in the near future.”
Tunable graphene antenna
Europe funded Project Nano RF has demonstrated a graphene antenna that operates in the microwave spectrum and which can be tuned using an external voltage. The antenna is less than 1mm thick, with a diameter of 100mm, which makes it one of the smallest such devices.
According to the researchers, the main application for the antenna will be in RF communications, where its tunability will allow switching of communication channels.