'Transparent Electronic Film' Developed for the First Time in the World, Unaffected by Rain or Seawater [Reading Science]

Yonsei Team Achieves Simultaneous Biological Signal Measurement and Optical Imaging

Paving the Way for Underwater Wearable Devices

Published in "Nature Communications"

Potential Applications in Brain Disease Research and Implantable Medical Devices

A transparent conductive nanofilm that does not lose performance even when exposed to rain, sweat, or seawater has been developed for the first time in the world. This technology enables simultaneous measurement of biological signals and real-time observation of internal tissues, even when attached to the skin or implanted in the brain. It is expected to open new horizons in next-generation wearable medical devices and brain disease research.

Yonsei University announced on June 30 that a research team led by Professor Kijun Yoo of the Department of Electrical and Electronic Engineering, in collaboration with RIKEN and the University of Tokyo in Japan, has developed the world's first transparent conductive nanofilm (BIPIN) that operates stably even in moisture-rich environments. The research findings have been accepted for publication in the international journal "Nature Communications."

Material structure of the transparent conductive nanofilm (BIPIN) and overview of attachment to skin and cerebral cortex. Provided by the research team

Accurate Measurement of Biological Signals Even Underwater

Transparent electrodes that can perform both biological signal measurement and optical imaging simultaneously are considered a core technology for next-generation medical devices. However, conventional electrodes are prone to corrosion or detachment from tissues when exposed to sweat, body fluids, or rain, making long-term use difficult.

The research team overcame these limitations by applying an ideal percolation network (BIPIN) structure that combines metallic nanomesh with a conjugated polymer and a fluorine-based ionomer.

The ultra-thin electronic film, about 200 nanometers thick, effectively blocks the penetration of moisture and ions while maintaining high transparency and electrical conductivity, even when tightly attached to skin or brain tissue.

In experiments, the film stably recorded electromyography signals not only in rainwater, seawater, and body fluids, but also in underwater environments such as swimming. In brain tissue, it successfully enabled simultaneous optical imaging and electrophysiological signal measurement without interference between the two modes.

Expected Applications in Wearables and Brain Disease Research

Research team photo. Hyunwoo Kim, Doctoral Candidate in the Department of Electrical and Electronic Engineering at Yonsei University (left), Professor Kijun Yoo. Courtesy of Yonsei University.

The research team explained that the key achievement of this technology is that it simultaneously addresses the moisture vulnerability and optical interference issues, which were the biggest limitations of existing transparent electrodes.

They anticipate the technology will be applicable to a wide range of bio-medical fields, including not only skin-attachable wearable medical devices but also long-term implantable neural interfaces, brain neural network research, and high-resolution biological imaging.

Professor Yoo stated, "This research presents a new bio-optoelectronic platform that enables stable electrophysiological signal measurement and optical imaging simultaneously, even in moist environments," adding, "We expect it will be widely used in the development of next-generation medical devices such as wearable bioelectronic devices and chronic implantable neural systems."

This content was produced with the assistance of AI translation services.