KAIST

<(From Left) Professor Inkyu Park, Dr. Seokjoo Cho, (Upper Right, From Left) Professor Ji-Hwan Ha, Researcher Jun-Ho Jeong , Professor Wei Gao>

“Diabetic ulcers,” which occur in patients with diabetes, are dangerous complications that can lead to amputation if the treatment window is missed. A joint research team has developed a “smart dressing patch” that can monitor wound conditions in real time.

KAIST (President Kwang Hyung Lee) announced on the 14th of May that a research team led by Distinguished Professor Inkyu Park of the Department of Mechanical Engineering, through joint research with Professor Ji-Hwan Ha of Hanbat National University (President Yongjun Oh), researcher Jun-Ho Jeong of the Korea Institute of Machinery & Materials (President Seog-Hyeon Ryu), and Professor Wei Gao of the California Institute of Technology (Caltech; President Thomas F. Rosenbaum) in the United States, has developed a “wireless, battery-free optoelectronic multi-modal sensor patch” for diabetic ulcer management.

The patch developed by the research team combines an optoelectronic sensor, which can simultaneously measure multiple types of biological information, with a functional dressing. It can analyze glucose concentration, acidity (pH, an indicator of hydrogen ion concentration), and temperature changes at the wound site in real time, and patients can check their condition themselves using a smartphone.

The research team fabricated a functional nanofiber dressing using electrospinning, a method that uses an electric field to create fibers much thinner than a human hair. This dressing changes color in response to increased glucose and changes in acidity that appear in diabetic foot wounds. In other words, if the wound condition worsens, the dressing color changes, allowing danger signals to be easily checked with the naked eye. Through this, abnormal signs that could lead to tissue necrosis can be detected and tracked over long periods in a non-invasive manner, meaning without cutting the skin or drawing blood.

The research team combined this with an optoelectronic system to improve diagnostic accuracy. A light-emitting diode (LED, a semiconductor device that converts electricity into light) embedded in the patch and a photodiode, a semiconductor sensor that detects light, measure the color change of the dressing as light reflectance and then convert it into an electrical signal.

This provides more accurate and stable data than ordinary camera-based imaging because it is less affected by changes in surrounding lighting.

In particular, the patch operates without a separate battery by applying a flexible circuit based on near field communication (NFC), a wireless communication technology that exchanges data over short distances. When a smartphone is placed near the sensor, the patch receives power wirelessly and operates, transmitting the measured data in real time. In other words, patients and medical staff can immediately check and respond to wound conditions using only a smartphone app, without separate complex equipment.

< Conceptual Diagram of a Multimodal Colorimetric Dressing and Optoelectronic Sensor for Diagnosing Diabetic Foot and Diabetic Diseases >

The technology developed in this study has high clinical value because it provides both intuitive visual signals and quantitative electronic data while imposing no physical burden on patients. It is also expected to contribute to improving the quality of life of patients with diabetes by enabling continuous wound management without repeated blood sampling.

Distinguished Professor Inkyu Park stated, “Research that began to reduce the pain of diabetic patients who have to prick their fingers with a needle every day has led to a technology for the preemptive diagnosis of complications,” adding, “This technology will become a core platform technology that can be expanded in the future to blood-free diagnostic technologies not only for diabetes but also for various chronic diseases.”

In this study, KAIST Dr. Seokjoo Cho and Professor Ji-Hwan Ha of Hanbat National University participated as co-first authors. The research results were published on March 26, 2026, in the international materials science journal Advanced Functional Materials. The paper was also selected as a Front Cover article of the journal.
 ※ Paper title: “Wireless, Battery-Free, Optoelectronic, Multi-Modal Sensor Integrated With Colorimetric Dressing for Diabetic Ulcer Management,” DOI: 10.1002/adfm.202532167

< Front Cover Image >

This research was supported by the Mid-Career Researcher Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT, the Alchemist Project of the Ministry of Trade, Industry and Energy, and the Daejeon RISE Center.