Photosynthesis-Inspired Nano-Bionic Leaf for Broadband Microwave Energy Absorption

Inspired by the light-management mechanism of photosynthetic leaves, we develop a nano-bionic leaf-like absorber for broadband microwave energy absorption. In situ pyrolysis of a metal-organic coordination polymer gel produces a multigradient heterostructure composed of a dense graphitic carbon outer layer and a mesophyll-like interior containing dispersed carbon spheres and phosphate nanosheets. This leaf-mimetic nanoarchitecture enables progressive microwave energy regulation by combining front-surface impedance matching with internal multiple scattering, interfacial polarization, conductive loss, and dielectric-magnetic dissipation. The optimized absorber achieves a maximum effective absorption bandwidth of 6.66 GHz, a minimum reflection loss of -49.6 dB, and a low matching thickness of 1.89 mm. Field simulations further reveal spatially differentiated energy dissipation, with electric-field localization in the carbon phase and magnetic-field localization in the phosphate phase. This work provides a biomimetic strategy for designing nanoarchitectured absorbers for thin and broadband microwave energy absorption.