A spider web-inspired MWCNT aerogel with cross-scale mechanical interlocking structure for infrared-radar stealth and smart distress signaling

Inspired by the spider web predation mechanism, a novel MWCNT/Ni/BC (MNB) aerogel with infrared-radar dual stealth and signal transmission was successfully prepared. • Ni chains and MWCNT/BC aerogel form a cross-scale mechanical interlocking structure that optimizes impedance matching for promoting electromagnetic wave attenuation. • The fluffy 3D space structure combine details excellent mechanical resilience with a conductive MNB aerogel network, enabling outstanding infrared stealth and signal transmission performance. Multifunctional materials integrating infrared stealth, electromagnetic absorption (EMA), and sensing are critical for next-gen intelligent soldier systems, yet the inherent trade-off between sensing and dual stealth performance hinders their development. Inspired by spider web predation, this study fabricated multi-walled carbon nanotube (MWCNT) /Ni chain/bacterial cellulose (MNB) aerogels via magnetic induction and directional freezing. By tuning Ni chain content and pore structure, a new generation of electromagnetic protection material integrating infrared-radar stealth and sensing was developed to enhance individual combat survivability. The optimized MNB aerogel exhibits exceptional EMA and impedance matching: a minimum reflection loss of −69.73 dB at 2.49 mm, specific RL of −2182.19 dB·mm −1 , and an effective absorption bandwidth of 8.14 GHz, while >99% absorption even at 120 °C. Meanwhile, attributable to its low infrared emissivity and excellent thermal insulation, the MNB aerogel maintains stable infrared stealth performance, consistently achieving a temperature difference of 34 °C between the target surface and the hot stage. Furthermore, its elastic conductive network enables a fast piezoresistive sensing response, demonstrating significant potential for individual distress signal transmission in combat scenarios. This study presents a simple strategy for next-gen intelligent electromagnetic protection materials with broad potential in thermal management, aerospace, and health monitoring.