Performance Maintained Even After 100 Washes... Development of 'Fiber-Type Temperature Sensor'

KAIST Research Team Develops Material for 'Wearable Electronic Devices'

A fiber-type temperature sensor material that maintains performance even after more than 100 washes has been developed. It is attracting attention for wearable electronic devices.

KAIST announced on the 20th that Professor Sungjoon Park's research team from the Department of Bio and Brain Engineering has developed a fiber-type temperature sensor hundreds of meters long using the Thermal Drawing Process (TDP). The Thermal Drawing Process is a method that uses heat to soften a large structure and then rapidly pulls it to produce fibers with the same shape and function as the complex structure.

Fiber and textile-type temperature sensors that can be easily applied to clothing are gaining attention due to the convenience of measuring temperature comfortably. Existing manufacturing methods for sensors (such as coating and spinning) face difficulties in mass production and can only produce simple structures and materials, requiring several additional processes to enhance physical and chemical stability.

To solve these problems, the research team used a ‘polymer-nanomaterial composite’ and the ‘Thermal Drawing Process’ in this study. They created a composite by mixing a polymer that melts when heated with nanoparticles whose resistance changes with temperature, then wrapped it in a flexible and stable polyethylene sheet to complete a cylindrical structure. Subsequently, by applying heat to the large structure and pulling it, they used the Thermal Drawing Process to reduce its size and transform it into a fiber form, successfully mass-producing thin, flexible, and physically and chemically stable fiber-type temperature sensors hundreds of meters long.

The produced fibers are drawn at once with a thin protective layer that can protect the sensor. Thanks to the protective layer, the sensor’s performance did not change even after 1,000 cycles of temperature and bending stimuli. It maintained stability when exposed to various chemicals and humidity. It was even confirmed to have excellent stability after 100 washes.

When the fiber-type temperature sensor was woven into actual fabric and worn, the research team confirmed that it could measure body temperature accurately matching the actual temperature and could measure temperature well without signal noise during activities such as walking. Additionally, by weaving the sensor into gloves, the team demonstrated its potential as electronic skin capable of measuring the temperature of contacted materials.

The research results were published on the 12th in the international journal Advanced Fiber Materials, a top 1.92% JCR journal in the textile field.

Professor Park said, "In the future, we expect the development of fiber and textile-type sensors based on the Thermal Drawing Process that can simultaneously detect various factors, not just temperature," adding, "By integrating these into smart clothing, they could be applied not only in healthcare but also in VR/AR, the metaverse, and everyday communication fields."