Scientists find new way to print antennas with graphene ink

Researchers printed on a piece of paper an antenna of compressed graphene that was good enough to act as an RFID tag. According to the makers, the antenna can be produced on a large scale, flexible and less harmful to the environment than existing rfid antennas.

Researchers from the University of Manchester write this in the journal Applied Physics Letters on Tuesday. Inks based on graphene and a solvent have been around for some time, but must be mixed with a binder to act as a good conductor. The binding agent must be removed afterwards or change its structure, because it acts as an insulating material. This removal, or annealing, takes place at temperatures that plastic or paper would not survive.

In order to circumvent the binder, the university and a company developed a way to improve the conductive properties. The researchers did this by allowing the graphene ink to dry after printing and then pressing it on with a roller. Then the graphene flakes are flat rolled.

Before and after pressing the graphene nanoflakes

After pressing the ink, the conductive properties were more than fifty times better. Compared to ‘traditionally’ produced graphene ink, the conductivity was twice as good. The eventually printed antenna on paper was about 14 centimeters long and 3.5 millimeters wide, and it radiated radio signals well.

Graphene-based RFID tags are cheaper and easier to make, according to the authors of the study. Current rfid tags are usually made of aluminum, copper or other conductive materials. The actual scientific article won’t be available here until Tuesday.