Fig. 3
From: Digital coding of mechanical stress in a dynamic covalent shape memory polymer network
Spatiotemporal control of partial plasticity by digital gray scale photothermal effect. a Time evolution of color during stress relaxation at 100 °C (strain: 70%, sample length: 4 cm). b Color change presented at a standard CIE-1931 color space (100 °C, strain: 150%). c Cyclic variation of light intensity (450 nm) with time corresponding to b. d Laser printed gray scale pattern (each square is 1 cm × 1 cm, gray scale of 1, 0.8, 0.6, 0.4, 0.2, and 0), and the corresponding infrared thermal image (the third colored line on the bottom represents the temperature scale). e Linear correlation between photothermal heating and the gray scale. f Gray scale photo of Mona Lisa and its infrared thermal image (the scale bar is 1 cm). g Normalized residual stress after photothermal heating for 1 min at different temperatures. h Infrared light-induced time evolution of color under polarized light in a pre-stretched film (strain: 70%) printed with a gradient gray scale pattern. Ink is kept on the sample due to the continuous nature of this experiment
