Just how tiny is the world’s smallest QR code?

That’s smaller than many bacteria. In fact, it’s so tiny that it can only be seen with an electron microscope. The QR code was developed by scientists from the TU Wien public research university in Vienna, Austria, in partnership with German startup Cerabyte. It was etched onto a thin ceramic film with the goal being that this particular medium would hold up well to wear and tear over time.

To put the QR code on the film, the team used focused ion beams. Each pixel is 49 nanometers, 10 times smaller than the wavelength of visible light — hence the electron microscope. This is three times smaller than the previous record, 5.38 square micrometers, achieved by a team at the University of Münster. The TU Wien team estimates that using their technology, an A4 paper sheet-sized ceramic film would be able to store more than 2 terabytes of data.