Hybrid Nanogels‐Based Printable Tattoos Inspired by Lady Costume from Tang Dynasty for Monitoring Solar UV Radiation

Abstract Inspired by the lady costume from Tang Dynasty, printable tattoos are prepared from hybrid nanogels to monitor ultraviolet (UV) radiation from sunshine. The hybrid poly(di(ethyleneglycol) methylether methacrylate‐ co ‐poly(ethylene glycol) methylethermethacrylate) nanogels containing graphitic carbon nitride (g‐C 3 N 4 ) nanosheets, abbreviated as hybrid P(MA‐ co ‐MA 300 )/g‐C 3 N 4 nanogels, are prepared by precipitation polymerization. Due to the excellent photocatalysis of the g‐C 3 N 4 nanosheets, the dyed hybrid nanogels can be rapidly photodegraded under sunshine. Based on the linear correlation between the discoloration of dyed hybrid nanogels and the dose of solar radiation, the UV radiation from sunshine can be simply monitored by checking the color in real‐time. By applying different types of dyes, the hybrid nanogels even can be used to trace the dose for the synthesis of vitamin D, induction of erythema and risk of skin cancer simultaneously. Favored by the stickiness of acrylate‐based polymers, the hybrid nanogels can be printed to the body as tattoos to realize decoration and UV detection. By simply switching the template for printing, the tattoo patterns can be easily changed according to personal interests and applied position on the human body. Therefore, the present hybrid nanogels can be a promising candidate to monitor the solar radiation dose and decorate the human body.