How small can a QR code get? A team of researchers has pushed the limits to an extreme, creating one so tiny it can only be detected using an electron microscope. Scientists at TU Wien, working with data storage company Cerabyte, produced a QR code measuring just 1.98 square micrometers, which is smaller than most bacteria. This achievement has now been officially confirmed and recorded in the Guinness Book of Records.
Beyond its size, the breakthrough could have major implications for long-term data storage. Traditional storage technologies such as magnetic drives or electronic systems tend to degrade within a few years. In contrast, encoding information into ceramic materials could preserve it for hundreds or even thousands of years.
Stable and Readable at the Nanoscale
“The structure we have created here is so fine that it cannot be seen with optical microscopes at all,” says Prof. Paul Mayrhofer from TU Wien’s Institute of Materials Science and Technology. “But that is not even the truly remarkable part. Structures on the micrometer scale are nothing unusual today — it is even possible to fabricate patterns made of individual atoms. However, that alone does not result in a stable, readable code.”
At extremely small scales, atoms can shift positions or fill gaps, which can erase stored data. “What we have done is something fundamentally different,” Mayrhofer explains. “We have created a tiny, but stable and repeatedly readable QR code.”
Ceramic Materials Enable Durable Data Storage
The key to this achievement lies in the material itself. “We conduct research on thin ceramic films, such as those used for coating high-performance cutting tools,” explain Erwin Peck and Balint Hajas. “For high-performance tools, it is essential that materials remain stable and durable even under extreme conditions. And that is exactly what makes these materials ideal for data storage as well.”
Using focused ion beams, the researchers engraved the QR code into a thin ceramic layer. Each pixel measures just 49 nanometers, which is about ten times smaller than the wavelength of visible light. As a result, the pattern is completely invisible under normal conditions and cannot be resolved using visible light. However, when viewed with an electron microscope, the QR code can be clearly and reliably read.
The storage capacity is also impressive. More than 2 terabytes of data could fit within the area of a single A4 sheet of paper using this approach. Unlike conventional storage systems, these ceramic data carriers can remain intact indefinitely and do not require any energy to maintain the stored information.
A New Approach to Long-Term Data Preservation
“We live in the information age, yet we store our knowledge in media that are astonishingly short-lived,” says Alexander Kirnbauer. Magnetic and electronic storage devices often lose data after only a few years, especially without continuous power, cooling, and maintenance. In contrast, ancient civilizations carved their knowledge into stone, allowing it to survive for thousands of years.
“With ceramic storage media, we are pursuing a similar approach to that of ancient cultures, whose inscriptions we can still read today,” Kirnbauer says. “We write information into stable, inert materials that can withstand the passage of time and remain fully accessible to future generations.”
Another major advantage is energy efficiency. Unlike modern data centers that require significant electricity and cooling, ceramic-based storage can preserve information without any ongoing energy input, helping reduce environmental impact.
Guinness Record and Future Applications
The record-setting QR code and its verification process, including electron microscope readout, were conducted jointly by TU Wien and Cerabyte in front of witnesses. The University of Vienna served as an independent verifier. TU Wien provided advanced materials science facilities along with the high-resolution electron microscopes at its USTEM center. The result has now been officially recognized by Guinness, with the new QR code measuring just 37% the size of the previous record holder.
“The now confirmed world record marks just the beginning of a very promising development,” says Alexander Kirnbauer. “We now aim to use other materials, increase writing speeds, and develop scalable manufacturing processes so that ceramic data storage can be used not only in laboratories but also in industrial applications. At the same time, we are investigating how more complex data structures — far beyond simple QR codes — can be written robustly, quickly, and energy-efficiently into ceramic thin films and read out reliably.”
This work points toward a more sustainable future for data storage, where information can be preserved securely for the long term with minimal energy use.