Lee Soohoon, Son Wonkyeong, Joshi Shalik Ram, Choi Changsoon, Kim Sunghwan
Department of Electronic Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
Department of Biomedical Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
Small. 2025 Sep;21(35):e2503580. doi: 10.1002/smll.202503580. Epub 2025 Jun 17.
Seamless integration between on-skin electronics and the skin is crucial for advanced personalized diagnostics, therapeutics, and human-machine interfaces. The challenge lies in creating an ideal interface that directly connects thin-film electronics with soft skin, ensuring both free skin respiration and stable device performance. Here, an electronic tattoo (e-tattoo) based on the ever-thinnest protein hydrogel that conforms to the skin's minutiae without air gaps is reported. The combination of sub-µm-thick silk film and carbon nanotube nanosheet (CNT-NS) enables the implementation of µm-thick e-tattoos. The extremely thin and strong skin-adhesion of silk allow conformal integration with skin contours, while mechanical and electrical properties of CNT-NS enable stable on-skin electronic operation. The e-tattoo exhibits high breathability, mechanical strength, and Ohmic electrical conductivity, supporting various biomedical applications. Strong light absorption of the CNT-NS enables photothermal patch applications, and the seamless skin-interface allows electrocardiogram detection with higher signal-to-noise than that of commercial gel electrodes. Additionally, the e-tattoo is applied as a triboelectric nanogenerator operated by bare skin touch, functioning as a self-powered Morse code transmitter. By sandwiching an electrolyte-infused silk film between two e-tattoos, a supercapacitor is implemented, demonstrating stable performance even under highly iterative charge/discharge cycles and mechanical deformation.
皮肤表面电子设备与皮肤之间的无缝集成对于先进的个性化诊断、治疗以及人机界面至关重要。挑战在于创建一个理想的界面，将薄膜电子器件与柔软的皮肤直接连接起来，确保皮肤能够自由呼吸且设备性能稳定。在此，报道了一种基于最薄蛋白质水凝胶的电子纹身（e纹身），它能贴合皮肤的细微之处且无气隙。亚微米厚的丝绸薄膜与碳纳米管纳米片（CNT-NS）的结合使得能够实现微米厚的e纹身。丝绸极薄且对皮肤有很强的附着力，使其能够与皮肤轮廓共形集成，而CNT-NS的机械和电学性能则实现了稳定的皮肤表面电子操作。该e纹身具有高透气性、机械强度和欧姆导电性，支持各种生物医学应用。CNT-NS的强光吸收能力使其可用于光热贴片应用，无缝的皮肤界面允许进行心电图检测，其信噪比高于商用凝胶电极。此外，该e纹身还可作为通过裸肤触摸操作的摩擦电纳米发电机，用作自供电的摩尔斯电码发射器。通过在两个e纹身之间夹入注入电解质的丝绸薄膜，实现了一个超级电容器，即使在高度重复的充放电循环和机械变形下也能表现出稳定的性能。
