POSTECH Researchers Develop Wearable Device for Precision Long-Term Skin Health Monitoring

POSTECH researchers have developed an innovative wearable device capable of precisely measuring the long-term impacts of environmental factors on skin health. This breakthrough is expected to open new avenues not only for the diagnosis and management of chronic skin diseases like atopic dermatitis, but also for identifying how environmental pollutants, such as fine dust, affect the individual skin barrier function.

A joint research team led by Professor Daeshik Kang (Department of Mechanical Engineering) announced that they have successfully developed the "Breathable Skin Analyzer (BSA)," a breathable wearable device capable of precisely monitoring skin barrier function over long periods.

The research was published in the October issue of the prestigious journal Nature Communications under the title: "Breathable, wearable skin analyzer for reliable long-term monitoring of skin barrier function and individual environmental health impacts."

Dr. In-Sik Hong (Center for Systems Biology, Massachusetts General Hospital), Ph.D. candidate Daseul Yim and Dr. Dongjin Kim (Department of Mechanical Engineering, Ajou University), and Ph.D. candidate Myeongrae Hong (Department of Mechanical Engineering, POSTECH) participated in the study as first authors. Professor Daeshik Kang (POSTECH), Professor Seung-Yong Han and Professor Je-Sung Koh (Department of Mechanical Engineering, Ajou University), and Professor Sung-Chul Seo (Seokyeong University) served as co-corresponding authors.

The skin serves as the primary line of defense protecting the body from the external environment. Skin Hydration (SH) and Transepidermal Water Loss (TEWL) are critical indicators used to evaluate skin barrier health. However, conventional devices are limited to short-term, spot-check measurements, failing to capture skin condition variations over circadian rhythms. Furthermore, long-term monitoring was challenging due to sweat accumulation and external environmental noise, often relying on patients' subjective evaluations, which limited accuracy.

To address this, the team developed the "Breathable Skin Analyzer (BSA)." The device incorporates a micro-shape memory alloy (SMA)-based bistable actuator and a breathable chamber structure. During measurement, it adheres closely to the skin to gather accurate data, while post-measurement, it lifts the sensor away to promote sweat evaporation. This mechanism minimizes skin irritation even during prolonged wear, enabling reliable and continuous monitoring.

Through clinical trials, the research team continuously measured skin hydration and TEWL over 28 days, establishing a correlation between fine particulate matter (PM) concentration changes and skin barrier damage. Notably, they identified statistically significant patterns in patients with atopic dermatitis—showing a simultaneous decrease in hydration and an increase in TEWL—and verified that lifestyle modifications, such as wearing masks and washing one's face, effectively mitigate skin damage.

Additionally, by applying the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm for data analysis, the team successfully filtered out abnormal data caused by showering or sweating, demonstrating the capability for precise skin health monitoring.

The newly developed BSA holds strong potential for various applications, including:

• Personalized skin health management
• Assessment of environmental pollution's impact on the human body
• Long-term clinical studies
• Smart healthcare industries

Designed in a watch-sized, lightweight form factor (13g) equipped with Bluetooth wireless communication, the device offers high commercial potential as it can be conveniently worn in daily life for several weeks or more.

Professor Daeshik Kang stated, "The BSA provides users with real-time feedback on their skin condition, serving not only as a tool for personalized diagnosis but also as a foundation for future healthcare platforms. Moving forward, we plan to further optimize the device to expand its versatility for infants and individuals with sensitive skin."

This research was supported by the Environmental Health Digital Investigation Technology Development Program of the Korea Environmental Industry & Technology Institute (KEITI).