Predicting Fatigue Damage in Hydrogels Through Force-Induced Luminescence Enhancement

Fatigue damage of polymers occurs under long-term load cycling, resulting in irreversible fracture failure, which is difficult to predict. The real-time monitoring of material fatigue damage is of great significance. Here, tough hydrogels are prepared with force-induced confined luminescence enhancement of carbonated polymer quantum dot (CPD) clusters to realize the visualization of fracture process and the monitoring of fatigue damage. The enhanced interactions induced by force between the clusters and the polymer in the confined space inhibit the non-radiative leaps and promote the radiative leaps to quantify the fatigue damage into optical signals. Rigid CPDs with abundant active sites on the surface can form dynamic reversible bonds with polymer and dissipate stress concentration, which significantly enhances the crack propagation strain (8000%) and fracture energy (26.4 kJ m^-2) of hydrogels. CPD hydrogels have a wide range of applications in novel information encryption and luminescent robotics.