[Reading Science] An ID That Disappears When It Touches the Skin

Professor Seunghwan Ko's Research Team at Seoul National University Develops Information Pattern Technology That Appears or Disappears in Response to Body Temperature

A wearable ID technology that can reveal or hide personal information simply by attaching it to the skin has emerged in Korea. Amid the increasing use of personal information in electronic data forms such as QR codes, this information encryption technology, which can be used in daily life without separate energy sources like ultraviolet rays or high heat, is attracting attention.

The National Research Foundation of Korea (Chairman Kwang-Bok Lee) announced on the 1st that Professor Seung-Hwan Ko's research team at Seoul National University has developed a technology to create information patterns that can disappear or appear in response to body temperature.

The information pattern that was visible inside the blue dotted line (left) disappears when attached to the skin due to temperature. Photo by Professor Go Seung-hwan

Professor Ko's research team attempted phase control of elastomers using liquid crystal elastomers that become transparent through 'phase transition,' a phenomenon where one phase changes to another under certain external conditions such as temperature and pressure. Using lasers, they were able to partially control transparency.

When the phase transition temperature was lowered to the level of human body temperature, the elastomer became transparent as soon as it touched the skin temperature. This means that the elastomer containing personal information can be artificially made visible or invisible after being attached to the skin. The research team also secured technology to rapidly produce information patterns such as QR codes.

According to the research team, not only can information patterns be created and encrypted, but the created information patterns can be completely erased and new information patterns can be produced again. This means that it is not limited to a single owner but can be used by multiple people.

Additionally, they succeeded in designing the elastomer to partially respond to light and operate accordingly.

When exposed to high-temperature red light, the folded remote control and pattern-encrypted digital image unfold by themselves. Photo by Professor Go Seung-hwan

The research team expects that this study will open possibilities for next-generation displays whose transparency changes with temperature, as well as various applications in industrial and medical fields such as the production of ultra-small soft robots that can move according to temperature.

Professor Ko explained, “This research can be used as a next-generation wearable ID card through information pattern creation and encryption via body temperature, and it will also play a significant role in the development of soft robots that can be operated by body temperature.”

Professor Ko added that overcoming the challenge of mass production is necessary for the practical application of this technology, stating, "The goal is to implement functional devices that can be utilized in broader application fields by controlling various physical properties."

The results of this research were published on March 26 in the internationally renowned materials science journal Nature Materials.

This content was produced with the assistance of AI translation services.