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Abstract Stimuli‐responsive soft materials (SRSMs) can change shape in response to external stimuli, such as heat or light, through non‐equilibrium kinetic processes like diffusion and viscoelastic relaxation. Steering the non‐equilibrium kinetic processes is crucial to enable programmable spatiotemporal shape morphing of SRSMs. However, achieving such behavior through simple control and facile fabrication remains a challenge. Herein, by regulating the non‐equilibrium kinetic processes in photothermally responsive shape memory polymer (SMP) strips, their programmable spatiotemporal shape‐morphing is demonstrated with a simple material system and constant external stimuli. Specifically, it is shown that how varying the angles of light incidence, light intensity, and material properties encode the programmable spatiotemporal behaviors. These experiments manifest that an SMP strip displays convexity inversion, flip‐forward motion, and rolling behavior in response to constant light illumination. Furthermore, it is shown that a twisted SMP strip exhibits different untwisted directions under different concentrated illumination areas. Finally, materials are patterned with different kinetic properties in an SMP strip, demonstrating the capability of SMPs to undergo more complex spatiotemporal shape‐morphing behaviors, such as twisted bending. This work achieves programmable spatiotemporal shape‐morphing behaviors of SMP by utilizing material intelligence, and provides essential design guidelines for morphing structures and soft robots.
Wu et al. (Sun,) studied this question.