We could store information in ice for thousands of years — not with ink or electronics, but with air. By subtly changing the shape and placement of bubbles trapped as water freezes, scientists have discovered a way to encode messages that could endure as long as the ice itself.

The study was Cell Reports Physical Science by Mengjie Song and colleagues at the Beijing Institute of Technology. It presents an entirely new way to store and retrieve information like Morse code or binary.

“These ice messages can be preserved for a long time and the messages they carry are easy to visualize and read,” said Song.

Glacial inspiration

Traditional information storage — paper, magnetic tape, the digital drive — struggles in extreme environments like Antarctica or the Moon. Ink fades, electronics fail, and extreme temperatures sap battery life. But ice thrives in the cold. Furthermore, ice already stores a lot of information about the past. It can offer clues about temperature, atmospheric chemistry, even volcanic eruptions. What if, the researchers wondered, we could use this as well?

It sounds crazy, but the team’s idea was relatively simple. If bubbles in glacial ice can hold history, perhaps we can use controlled bubbles to write messages into newly formed ice.

When water freezes, it pushes and squeezes gases together, creating pockets of air: bubbles. These bubbles are egg-shaped (if the ice freezes fast) and needle-shaped, if the ice freezes slowly. If you could alternate how ice freezes, you could create a binary type of message. Researchers considered multiple approaches, but binary coding emerged as the more efficient approach. It can store over ten times more information than Morse code.

“Since bubble position and shape are determined by the freezing rate, it is possible to manually control the freezing rate to manipulate the shape and distribution of bubbles in ice,” says Song.

To test the idea, they created thin layers of water sandwiched between transparent sheets and froze them using a carefully monitored cold plate. By adjusting how quickly the ice formed (freezing rate) they could manipulate the size, shape, and layering of air bubbles that formed.

The team also found that suddenly increasing the freezing rate (by lowering the temperature of a cold plate) resulted in a single bubble layer. This offered a layering of information, with each “bubble layer” being a message.

With these insights, they set out to record their message. They even built a decoding system: a camera captures a grayscale image of the ice slice, and software reads the position and brightness of the bubbles. From this, the software reconstructs the message.

Could this actually be used?

For now, the capacity is modest — a few sentences per ice cube. But the team says the system could be made more efficient and scaled up. They say that eventually, ice storage could become a viable method in frigid environments.

Of course, the system depends on the preservation of ice. But in environments with stable subzero temperatures — think Antarctica, deep caves, or cryogenic labs — the method could provide a low-energy, resilient, and visual form of information storage.

“In naturally cold regions, the use of trapped air bubbles as a means of message delivery and storage uses less energy than telecommunication and is more covert than paper documents,” says mechanical engineer and author Mengjie Song.

The team is now exploring how gas types, pressures, and 3D geometries influence bubble formation. They want to explore how to incorporate more complex types of information. They also also hope to link their findings to glacier dynamics and material science more broadly.

“Our findings can be widely applied in many areas,” says Song. “In our daily life, we can manipulate bubbles to efficiently produce ice with different bubble contents and create beautiful ice sculptures. In industry, our research can help with metal smelting and manufacturing, as well as de-icing of aircraft and ships.”

For now, it’s still a rudimentary medium of communication. It’s unlikely to replace hard drives or satellites anytime soon. But in extreme environments, it can have its place.

The study was published in Cell Reports Physical Science.