Fig. 2: The regulation of the stress-relaxation of the dual dynamic hydrogel by visible light.

a The stress-relaxation of the hydrogels with different dynamic cross-linkers under the dark condition, as measured by rheology, with constant stiffness at 2 kPa. b Analysis of changes in stress-relaxation behavior using different crosslinkers, with the light intensity fixed at 20 mW/cm² as depicted in a. n = 8, 9 (ALYDS), 6 and 7 (MDADS), 4,4 (PBEDDS) independent samples (0, 20 mW/cm²). c Stress relaxation tests on a dynamically crosslinked ALYDS hydrogel subjected to 15% strain, with stress values normalized to the initial stress. d τ_1/2 of the ALYDS hydrogel under various light exposure conditions, as measured by rheology. n = 7, 9, 8, 9, 9 (0, 5, 10, 20, 40 mW/cm²) independent samples. e Time-dependent changes in viscoelastic creep compliance (J) of the ALYDS hydrogel. f Variation in linear average creep rates (<1/η>) of ALYDS hydrogel under different light intensities as depicted in. n = 3 per group from 3 independent hydrogels. g Exchange reactions involving TETD and PBEDS. h HPLC analysis of the mixed PBEDS (0.01 M) and TETD (0.01 M) in CH3CN/H2O over time. i Reactant concentration change in the dark and under visible light (445 nm) in CH3CN/H2O at room temperature. j Rate constant (k) in TDS-exchange reaction under various light intensities. The Rate study of i, j included three replicates for each group (n = 3). The data in b, d, f, and j are presented as mean values ± S.D.