Screen-printed ultra-thin and multifunctional e-tattoos towards epidermal sensors

Conformal e-tattoos have recently received widespread attention because of their great potential for precise and immediate monitoring of physiological signals. However, expensive materials or complex fabrication processes are often required to obtain e-tattoos that meet the above application requirements. Here, we propose a facile strategy for the preparation of e-tattoos via screen printing while achieving versatile parameters collection capabilities. The screen printing inks can be obtained only by mixing and stirring carboxylated MWCNTs water slurry, elastomer transparent glue, glycerin and commercial ink according to the needs of target signal detection. Furthermore, a layer of ultra-thin medical pressure-sensitive adhesive layer was subtly involved in the temperature and humidity sensitive e-tattoos, successfully avoiding the mutual interference between the physical signals and the electrophysiological signals. The continuous monitoring of sEMG signals, ECG signals, local humidity conditions, and skin temperature changes can be achieved by applying the multifunctional e-tattoo platform onto the human skin surface. This technology shows promise as a potential avenue for the advancement of electronic tattoo sensing in the future.