A new electrocardiogram patch that eliminates the need for cold gel application or adhesive-induced skin irritation has been developed by South Korean researchers.
A research team led by Professor Chung Hoon-ui at the Department of Mechanical Engineering at Ulsan National Institute of Science and Technology (UNIST) announced on January 9 that they have developed a high-performance ECG patch using liquid metal and micro-structured rubber silicone that requires neither gel nor adhesive.
The patch features liquid metal tubes 20 micrometers wide coiled in a snail-shell pattern. The bottom of the tubes touching the skin has an open structure, allowing cardiac signals to transmit directly to the liquid metal electrodes. This enables accurate heartbeat detection without gel.
To prevent liquid metal from leaking through the open bottom under pressure, the research team designed inward-curling horizontal protrusions at the base of the tubes. The tubes are thin enough that users do not feel the typical coldness of metal.
Microscopic protrusions measuring 28 micrometers in diameter and 20 micrometers in height across the patch surface serve as adhesive. The protrusions feature mushroom-cap edges that conform to skin's micro-contours, increasing contact area and physical adhesion strength.
The patch demonstrated electrode resistance more than five times lower than commercial patches, meaning it can detect subtle signals and accurately capture heartbeat data even during vigorous movement.
With adhesion strong enough to support 100 grams of weight, the patch minimizes noise from poor attachment. During activities such as walking and running, it maintained signal accuracy approximately twice as high as commercial ECG patches.
Unlike disposable hospital patches, this device can be reused more than 500 times with superior durability. Its adhesion derives from microstructures rather than one-time adhesives, and it maintains accuracy over extended periods without gel that can dry out.
"We solved both the liquid metal leakage problem and skin adhesion issue simultaneously through precise structural design alone," said Professor Chung. "We expect this to serve as foundational technology for next-generation wearable systems, including long-term health monitoring for patients with sensitive skin and high-precision human-machine interaction interfaces."
The research team has transferred the technology to Anvics Lab for commercialization. The venture was selected for the Technology Incubator Program for Startup (TIPS) supported by the Ministry of SMEs and Startups, recognizing its commercial potential, and has secured early-stage investment.
Anvics Lab was co-founded by Professor Chung and Professor Kim Jae-jun from the Department of Electrical and Electronic Engineering. The company plans to capture the next-generation wearable healthcare market by combining its proprietary patch technology with on-chip AI solutions.
The research was published as the Inside Front Cover article in the international journal Advanced Science on January 5. The study was supported by the Ministry of Science and ICT, the Ministry of Trade, Industry and Energy, and the National Research Foundation of Korea.