Flexible and durable programmable EMI shielding via shape memory layered EP foam induced by supercritical CO₂

The growing prevalence of electromagnetic technologies has highlighted the critical need for adaptive shielding materials in modern communication systems. However, traditional composites are unable to cope with the dynamic electromagnetic environments found in critical applications such as aerospace and wearable technology. This study used supercritical CO₂ technology to prepare lightweight flexible electromagnetic interference (EMI) shielding foams with shape memory (SM) function, which achieved dynamic regulation of EMI shielding effectiveness (SE) through self-fixed deformation behavior. By constructing carbon nanotube (CNT)-graphene hierarchical conductive network, a 12 order of magnitude leap in conductivity was achieved at only 3 wt% of ultralow filler loading. Incorporating carbon fiber cloth (CFC) as an interlayer enhanced both shape fixation and recovery rates to 99.99 %, while boosting specific EMI SE to 1060.43 dB·cm²/g. The material achieves absorption-led electromagnetic wave dissipation through a unique "absorption-reflection-absorption" synergistic mechanism, which greatly reduces secondary electromagnetic wave pollution, and exhibits 79 % wide-area EMI SE tunability (48.78-10.11 dB) through shape memory actuation. In addition, this mechanically adaptive foam maintains excellent durability in 40 cycles of SM testing and 100 cycles of heat cycle testing. Practical application was verified through an adaptive smart conference system capable of shape-mediated signal switching for secure information control. This work demonstrates how dynamic responsiveness, excellent shielding performance, and reliable operational stability can be achieved simultaneously, with important implications for 5G communications, aerospace, and next-generation electronic systems.