Agile Stealth: Bioinspired Metamaterials with Continuous Dynamic Tuning

The simultaneous realization of high-efficiency broadband absorption and dynamic frequency agility in electromagnetic metamaterials is a critical yet challenging goal for advanced stealth technologies. Here, a bioinspired reconfigurable metamaterial is introduced that overcomes this limitation through a novel dynamic structure-function design. Inspired by the moth-eye's truncated cone morphology, the metamaterial integrates a mechanical transmission system to precisely control the displacement of internal petal-shaped structures. This unique mechanism unlocks exceptional dual-mode performance: it maintains ultra-wideband absorption (≥90%) across a vast 2-40 GHz spectrum while simultaneously enabling the continuous tuning of at least six distinct, high-efficiency (≥99%) absorption peaks, each with a tuning bandwidth over 3 GHz. The geometric reconfiguration actively reshapes surface impedance, creating a synergistic effect that enhances overall performance. Consequently, the metamaterial demonstrates significant broadband radar cross-section (RCS) reduction and provides adaptive, deep suppression at specific threat frequencies. By incorporating coded driving, 2D control of frequency and amplitude is also realized. This integrated approach paves the way for the next generation of intelligent and high-performance adaptive stealth systems.