DGIST successfully develops ultra-thin nanomesh electrodes for breathable "electronic skin"

□ DGIST (President Kunwoo Lee) announced that a joint research team led by Professor Seongwon Lee from the Department of Physics Chemistry, Professor Hyunil Kang of Hanbat National University, and Professor Jongwook Roh of Kyungpook National University has successfully developed a high-resolution electronic skin (e-skin) device on a breathable (nanomesh) substrate using transfer technology employed in semiconductor manufacturing.

□ E-skin is an ultra-thin electronic device that adheres firmly to the surface of the human body or living tissue to monitor health or measure biosignals. For e-skin to function effectively, ‘conformal contact,’ which closely follows the skin's contours, and high breathability, which reduces skin irritation and inflammation caused by sweat and moisture trapped inside even after long-term use, are essential. In this context, nanomesh substrates, where polymer nanofibers are intertwined like a net, are gaining attention as next-generation e-skin materials because of their excellent breathability.

□ However, there were limitations in using them in electronic device production because it is difficult to apply them to precise microfabrication processes that operate at high temperatures because the nanomesh surface has a rough structure entangled with fibers and the polymer material is vulnerable to heat.

□ To overcome these structural limitations, the team introduced a new method called indirect transfer by adapting the transfer technology used in semiconductor device manufacturing to the nanomesh structure. This allowed the team to successfully develop electronic circuits with high-resolution patterns on nanomesh substrates.

□ While existing nanomesh electrodes typically need to be at least 100 nm thick to maintain stable conductivity, the newly developed ultra-thin nanomesh electrodes achieved high electrical conductivity even at thicknesses of 20 nm or less. Additionally, these electrodes demonstrated excellent durability with minimal performance loss under extreme deformation, such as bending radii of 0.5 to 2.5 mm, exposure to various chemicals like water, hydrogen peroxide, and acetone, as well as physiological conditions of the skin, including high temperature, humidity, and pH fluctuations. This proves their high suitability for electronic skin applications.

□ Professor Seongwon Lee said, "High-resolution yet breathable electrodes are a key technology for developing next-generation wearable devices. This achievement marks a significant step toward commercializing breathable electronic skin."

□ This research was funded by the National Research Foundation of Korea's Regional Innovation Leading Research Center Project and DGIST’s general program. The results were published in the prestigious international journal Materials Today