China's stealth jet coating reduces radar signal intensity by 700x

Chinese researchers from the People’s Liberation Army and China Aerospace Science and Industry Corporation have developed an ultra-thin stealth coating derived from loofah to significantly reduce radar signal detection of fighter jets. By carbonizing dried loofah and embedding it with nickel cobalt oxide (NiCo₂O₄) magnetic nanoparticles, the resulting composite, named NCO-2, absorbs over 99.99% of incident electromagnetic waves in the Ku-band frequency range (12-18 GHz). At just 4mm thick, this coating can reduce reflected radar signal intensity by nearly 700 times, effectively shrinking a stealth aircraft’s radar cross-section from 50 square meters to less than 1 square meter, even when radar beams come from directly above. The coating’s effectiveness is attributed to the loofah’s natural 3D network of cellulose fibers, which, when carbonized, form a lightweight conductive scaffold with mazelike pores. Electromagnetic waves entering this structure undergo multiple internal reflections, increasing absorption