Elastic, flexible, and tough hierarchical polyimide aerogels with dynamic reversible physical entanglement structure

Polyimide aerogels are renowned for their exceptional thermal stability and low dielectric constant but are constrained by excessive rigidity, limiting their application in flexible microelectronics, aerospace systems, and antenna technologies. This study presents novel hierarchical aerogels featuring dynamic reversible physical entanglements – layer-cake-like and cheese-like structures – derived via a solvent-tunable bubble templating method. These hierarchical structures enable unrestricted molecular chain mobility during deformation, efficiently mitigating stress concentration. The dynamic reversible entanglement network facilitates efficient stress redistribution under compression or torsion, while disentangled segments reform during recovery, significantly enhancing mechanical toughness. The layer-cake-like aerogel withstands compressive strains up to 80 %, retains structural integrity over hundreds of loading–unloading cycles, and achieves a toughness of 2099.33 kJ⋅m⁻³. Concurrently, the cheese-like aerogel exhibits shape memory behavior. The aerogels developed in this work not only exhibit superior resilience but also demonstrate excellent electromagnetic wave transmission properties. These advancements establish a framework for designing resilient, multifunctional aerogels, paving the way for future flexible electronic materials.