Muscle‐Inspired Super‐Flexible Phase Change Materials with Programmable Deformation for Photothermal Actuation

Abstract Phase change materials (PCMs) with remarkable latent heat storage/release capacity have demonstrated prominent advantages in energy conservation and efficient thermal management. Nevertheless, simultaneously achieving high thermal energy storage capacity, excellent toughness, and flexibility in PCMs is a significant challenge for programmable deformations when used in complex environmental scenarios. A flexible PCM is reported with programmable deformation constructed through a three‐dimensional (3D) dynamic cross‐linked network. This approach has culminated in the development of homogeneously cross‐linked and self‐supporting polyurethane‐based solid‐solid PCM with graphene enhancement, which exhibits exceptional properties of high latent heat storage/release capacity (∆H_m = 105.3 J g⁻¹, ∆H_c = 105.0 J g⁻¹), high toughness (ε = 1543%, σ = 19.2 MPa), excellent flexibility, and shape memory behavior (R_r = 90.3%). Notably, when subjected to photothermal stimulation, it can lift objects weighing more than 2620 times their weight, presenting a working density of 1330 kJ m⁻³. This flexible PCM, which simultaneously possesses a high latent capacity and photothermal‐driven performance, opens a new pathway for artificial muscles or soft robots with the requirements for energy conservation and thermal management in complex scenarios.