# Self-Sensing NiFe@N-doped Carbon Aerogel: Integrating Excellent Radar Stealth, Inherent Structural Health Monitoring, Thermal Management, and Flame Retardancy

## TL;DR

A new carbon aerogel material is developed that can absorb radar waves, monitor its own structural health, manage heat, and resist flames.

## Contribution

A multifunctional carbon aerogel is fabricated with integrated radar stealth, structural health monitoring, thermal management, and flame retardancy.

## Key findings

- The NFNCA achieved a minimum reflection loss of −53.49 dB at 1.93 mm.
- The aerogel has an effective absorption bandwidth of 6.24 GHz (11.76–18.00 GHz).
- The material can serve as a strain sensor for structural health monitoring.

## Abstract

The biomimetic honeycomb-like porous magnetic NiFe@N-doped carbon aerogel (NFNCA) was efficiently fabricated through chemical cross-linking, in situ growth, unidirectional freeze-drying, and pyrolysis carbonization.The synergistic effect arising from the 3D conductive networking structure, diverse heterogeneous interfaces, magnetic/dielectric multi-component, and multiple loss pathways of NFNCA endowed this carbon aerogel with outstanding impedance matching and electromagnetic wave attenuation performance.The NFNCA featured excellent microwave attenuation, real-time monitoring of structural integrity, infrared thermal stealth, thermal management, and flame retardancy capabilities.

The biomimetic honeycomb-like porous magnetic NiFe@N-doped carbon aerogel (NFNCA) was efficiently fabricated through chemical cross-linking, in situ growth, unidirectional freeze-drying, and pyrolysis carbonization.

The synergistic effect arising from the 3D conductive networking structure, diverse heterogeneous interfaces, magnetic/dielectric multi-component, and multiple loss pathways of NFNCA endowed this carbon aerogel with outstanding impedance matching and electromagnetic wave attenuation performance.

The NFNCA featured excellent microwave attenuation, real-time monitoring of structural integrity, infrared thermal stealth, thermal management, and flame retardancy capabilities.

The online version contains supplementary material available at 10.1007/s40820-026-02128-5.

Biomass carbon-based aerogels derived from collagen protofibrils are gaining considerable attention in electromagnetic protection. However, achieving a well-designed microstructure, optimized magnetic and dielectric loss components, and integrated multifunctionality within a single material system remains a significant challenge. Herein, a three-dimensional (3D) hierarchically biomimetic honeycomb-like porous magnetic NiFe@N-doped carbon aerogel (NFNCA) is obtained via a simple strategy involving in situ growth, freeze-drying, and pyrolysis carbonization. Driven by the synergy of a 3D conductive networking structure, magnetic and dielectric multi-components, numerous heterogeneous interfaces, and diverse loss pathways, the optimized NFNCA exhibits exceptional electromagnetic wave attenuation capability, evidenced by a minimum reflection loss (RL) of −53.49 dB at 1.93 mm and an effective absorption bandwidth of 6.24 GHz (11.76–18.00 GHz). Furthermore, the exceptional radar stealth, infrared thermal stealth, thermal management, and flame retardancy characteristics of NFNCA render it a promising candidate for multiple applications in demanding environments. Interestingly, the 3D cross-linked conductive network of NFNCA can serve as strain sensors to detect changes in the internal structure of carbon aerogels. Hence, this work provides a feasible design strategy for developing lightweight, high-efficiency, and multifunctional biomass-based carbon aerogel electromagnetic wave absorbing materials for various application scenarios.

The online version contains supplementary material available at 10.1007/s40820-026-02128-5.