A joint research team led by professors Choi Chang-soon and Kim Seong-hwan from the Department of Biomedical Engineering, School of Electrical and Biomedical Engineering at Hanyang University, has developed a “multifunctional ultra-thin electronic tattoo (E-tattoo)” that can conformally adhere to the skin and integrate various physiological sensing and energy device functionalities.

The team successfully addressed two long-standing challenges in wearable electronics: skin biocompatibility and mechanical adaptability. In particular, they overcame the limitation of hydrogel-based devices, which often lose mechanical strength as they become thinner, making them impractical for daily use.

The newly developed electronic tattoo integrates a nanometer-thin silk protein hydrogel layer (just a few hundred nanometers thick) with high-conductivity carbon nanotube (CNT) nanosheets. Despite its extreme thinness — about one-hundredth the thickness of a human hair — it maintains excellent mechanical robustness. This allows it to adhere securely to the skin even during dynamic movements and can be easily attached simply by moistening the skin and letting it dry.

This electronic tattoo is capable of multiple functions, including ▲ electrocardiogram (ECG) monitoring, ▲ serving as a photothermal therapy patch, ▲ acting as a triboelectric nanogenerator (TENG), and ▲ functioning as a skin-mounted supercapacitor. Notably, it demonstrated superior ECG signal detection performance compared to commercial gel-based electrodes and exhibited outstanding light absorption and thermal transfer properties, making it applicable for on-skin thermal therapy. Furthermore, the triboelectric effect enables self-powered energy generation from simple finger touches without an external power source, and it maintains over 97% energy storage efficiency, validating its potential as an independent power source for wearable electronics.

Professor Kim Seong-hwan stated, “This research represents an innovative achievement in creating electronic devices that naturally integrate with the skin by combining biocompatible protein materials and advanced electronic technologies. It holds significant potential for applications in wearable healthcare, human–machine interfaces, and next-generation self-powered electronic devices.”

This work was supported by the Ministry of Science and ICT under the “Fast-Track Technology Commercialization Project for Next-Generation Promising Technologies” and the “Global Frontier Research Center Program.” The research was published on June 17 in Small, a prestigious international journal in materials science and nanoelectronics. The paper, titled “μm-thick and water-taping protein electronic tattoos for multifunctional on-skin electronics,” lists master’s student Lee Su-hoon and postdoctoral researcher Dr. Son Won-gyeong as co-first authors, with professors Choi Chang-soon and Kim Seong-hwan serving as corresponding authors.

The 토토사이트 토토나라 team plans to further expand their work into applications for biosignal monitoring, medical diagnostics, and self-powered energy devices in the field of next-generation wearable electronics.