Carbon-based materials have been recognized as a promising method to eliminate electromagnetic interference (EMI) shielding and electromagnetic (EM) wave absorption. However, developing lightweight, ultrathin, and efficient EM wave-shielding and wave-absorbing materials remains a challenge. Herein, a series of magnetic porous carbon composite films with a hierarchical network structure were fabricated via pyrolysis of porous polyimide (PI) films containing magnetic metallic salts of Fe­(acac)3 and Ni­(acac)2. After pyrolysis, the obtained uniform porous carbon films (CFs) possess a favorable EMI-shielding efficiency (SE) of 46 dB in the X-band with a thickness of ∼0.3 mm. In addition, a higher EMI SE of 58 dB can be achieved by increasing the thickness of the porous CF-20Ni to 0.53 mm. Moreover, the CF-20Ni composites also present effective EM wave-absorbing performance of RLmin = – 30.2 dB with a loading amount of 20 wt % at 13.0 GHz owing to the hierarchically conductive carbon skeleton, magnetic Ni nanoparticles, and dielectric interlaced carbon nanotube cluster within the micropores. These novel lightweight and ultrathin porous CFs are expected to be attractive candidates for efficient EM wave absorption and EMI shielding.

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High-performance and light-weight polymer foams with ultralow dielectric constant, good thermal stability, and high mechanical strength are greatly needed in aviation and aerospace fields. In this work, cross-linked and rigid polyimide (PI) composite foams were fabricated based on norbornene terminated polyamide ester oligomer precursor powders via thermal foaming method. The obtained PI composite foams exhibit outstanding characteristics of light weight (90–130 kg·m–3) and high mechanical strength. When the glass fiber (GF) loading was 10 wt %, the compressive strength and modulus of PI/GF composite foams reached 1.7 and 49.6 MPa, respectively. Moreover, the PI foams exhibit remarkable thermal stability and fire-resistant property (LOI > 42%). The thermal conductivity of the prepared PI foams was measured to be in the range of 0.039–0.052 W·m–1·K–1 at room temperature. In addition, the PI composite foams present ultralow dielectric characteristic (tan δ = 0.006–0.008 at 10 GHz) and prominent wave-transparent performance (>95%) in the X band (8.2–12.4 GHz). These beneficial integrated properties enable the resultant PI composite foams to be attractive candidates for applications in aviation and aerospace fields.

Wearable electronic skins have aroused extensive interest in health detection, human–computer interaction, and robotics. However, it remains a great challenge to realize the multifunctional electronic skin with a wide detection range, high sensitivity, multi‐stimulus response, and wearable comfort on a single device. Here, a flexible porous thermoplastic polyurethane (TPU)/carbon black (CB) multimodal sensor that perceives multiple stimuli of pressure, strain, and humidity is prepared by the water vapor‐induced phase separation method. The as‐prepared device exhibits a wide pressure detection range (up to 49 kPa), excellent sensitivity (0.21 kPa−1), fast response (150 ms), and recovery time (120 ms). Furthermore, as a strain sensor, it is not only highly stretchable (730%), but also can operate over a strain range of 0–240% with a sensitivity of up to 1485.2 and excellent durability. Moreover, the designed sensor can detect humidity changes from 35% to 90% and has a fast response time (1.2 s), while enabling non‐contact sensing of a fingertip. Importantly, the porous TPU/CB film presents excellent breathability, enabling it to achieve a high level of comfort. Therefore, the perfect integration of these features ensures the potential applications of porous TPU/CB sensors in human activity detection, exhale monitoring, and breathable wearable devices.

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