A joint research team from the Korea Advanced Institute of Science and Technology (KAIST) has developed as a wireless, battery-free optoelectronic multi-modal sensor patch that can monitor wound conditions, such as diabetic foot ulcers, in real time. The smart 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 by placing it near the sensor.
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.
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.












