Multifunctional intelligent flexible Janus film for superior continuous X-ray shielding integrated with strain sensing

X-ray equipment often needs to be used in complex and variable environments. Combining X-ray shielding materials with pressure sensing capabilities can ensure that the equipment effectively shields X-rays while under pressure, safeguarding operational safety. In this study, the Janus structure was designed to be equipped with high shielding performances and intelligence for Cs-Pb-Br systems perovskite (Cs-Pb-Br)/MXene/aramid nanofiber (ANF) composites. In Cs-Pb-Br/MXene/ANF Janus film, the rational longitudinal distribution of Cs-Pb-Br originated from Janus structure and the internal reflection originated from layered MXene significantly enhance the X-ray shielding performances. Kill two birds with one stone, the layered MXene in Janus structure endows film with sensitive mechanical sensing properties. The attenuation efficiency and mass attenuation coefficient of Cs-Pb-Br/MXene/ANF Janus film were 70.5–83.2 % and 83.2–121.5 cm 2 /g under a continuous X-ray generated from a tungsten target with applied voltage ranging from 20 kV to 70 kV. The Janus film demonstrated ideal strain sensing performance, lightweight (0.96 cm 2 /g), robust tensile stress (25.5 MPa), and excellent flexibility, laying a foundation for producing next generation of X-ray shielding materials, which are light, flexible and intelligent.