Stretchable Luminescent Perovskite-Polymer Hydrogels for Visual-Digital Wearable Strain Sensor Textiles

The integration of a display function with wearable interactive sensors offers a promising way to synchronously detect physiological signals and visualize pressure/stimuli. However, combining these two functions in a strain sensor textile is a longstanding challenge due to the physical separation of sensors and display units. Here, a water-stable luminescent perovskite hydrogel (emission band approximately 25 nm) is constructed by blending as-prepared CsPbBr3@PbBr(OH) with stretchable polyacrylamide (PAM) hydrogels. The facile introduction of CsPbBr3@PbBr(OH) endows the hydrogels with excellent optical properties and a high mechanical strength of 51.3 kPa at a fracture strain of 740%. Interestingly, the resulting hydrogels retain bright green fluorescence under conditions including water, ultraviolet light, and extensive stretching (> 700%). As a proof-of-concept, a novel wearable stretchable strain sensor textile based on these hydrogels is developed, and it displays visual-digital synergetic strain detection ability. It can perceive various motions on the human body in real time with electronic output signals from changes in resistance and simultaneously readable optical output signals, whether on land or underwater. This work provides a meaningful guide to rationally design perovskite hydrogels and accelerates the development of wearable visual-digital strain sensor textiles.