World’s smallest QR code is thinner than a lightwave
QR codes are designed to be used as quickly and easily as possible. But while tens of millions of black-and-white grids are used every day, few people are likely to find much use in a grid that requires an electron microscope to read. Regardless, an example made at the Austrian Technical University of Wien (TU Wien) measuring just 1.98 square micrometers now officially holds the Guinness World Record for the world’s smallest QR code.
This may come as a surprise, but the QR code has been around for over 30 years. First introduced in 1994 by Japanese engineer Masahiro Hara, the “quick response” system initially helped manufacturers streamline the labeling of automotive parts. But while barcodes are machine-readable optical images linked to individual items, QR codes store much more data. This is how they incorporate so many different types of additional information. Such as location, ID details and even web tracking. In just a few years, technology has developed to support an increasingly digital world. In 2020, QR codes were literally saving lives during the COVID-19 pandemic by enabling contactless interactions and payments around the world.
The new micrometer-sized design created by researchers at TU Wien isn’t meant to point your smartphone at a restaurant’s brunch menu, but it does present promising advances in the field.
“The structure we created here is so fine that it cannot be seen at all with optical microscopes,” materials scientist Paul Mayrhofer said in a statement. “But that’s not even the really remarkable part. Micrometer-scale structures are nothing unusual today: it’s even possible to make patterns made up of individual atoms. However, this alone doesn’t make for stable, readable code.”
Working with data storage technology company Cerbyte, Mayrhofer and his colleagues were particularly interested in identifying a material durable enough to be used repeatedly at the atomic level. The answer came in the form of extremely thin and stable ceramic films, traditionally used to coat high-performance cutting equipment.
Instead of a standard printer, the researchers relied on focused ion beams to etch the QR code into a ceramic layer. Each pixel measured just 49 nanometers, or about 10 times smaller than a wavelength of visible light. This makes it literally impossible to see not only with the human eye, but also with most optical equipment. Researchers compared it to hands as calloused as an elephant’s foot trying to palpate Braille. This is where electron microscopy became crucial to the project. By imaging and resizing the QR code on a computer screen, the team was able to take out their smartphone cameras and successfully scan the data.
Data storage is already vital to today’s society, and it will only become more so with time, but time is not on the side of most of today’s storage options. Although they contain large amounts of information, physical forms like Blu-ray discs and even SSDs eventually deteriorate.
“We live in the information age, and yet we store our knowledge in media that are surprisingly short-lived,” said materials researcher Alexander Kirnbauer.
Developing new storage methods that are cost-effective, environmentally friendly and reliable is essential to ensuring data resilience for generations to come. In a way, it’s a story that has come full circle: like prehistoric civilizations carving information into stone, scientists are now performing almost identical tasks, but on a much larger scale, a lot on a smaller scale. The team estimates that an area equal to a sheet of printer paper could hold more than 2 terabytes of data if printed with their QR codes.
“With ceramic storage media, we are pursuing an approach similar to that of ancient cultures, whose inscriptions we can still read today,” Kirnbauer added. “We write information on stable, inert materials that can withstand the passage of time and remain fully accessible to future generations. »
The best new PopSci 2025 releases
