Tunable Metamaterial Perfect Absorbers Using Oracle Bone Script Configurations with Reversible Single‐ and Dual‐Resonance Transition Characteristics

Abstract Oracle bone script, the earliest known form of mature Chinese writing, it features unique geometric structures that have rarely been explored in the design of metadevice. This study presents two novel metamaterial perfect absorbers (MPAs) based on metal‐insulator‐metal (MIM) configurations inspired by the oracle bone characters “abundance” and “wood” consisting of a trunk in the middle and branches aside, which are denoted as MPA‐丰 and MPA‐木, respectively. By modulating the angle between the branches and the trunk using micro‐electro‐mechanical system (MEMS) technology, MPAs achieve dynamic near‐perfect absorption in the mid‐infrared (MIR) spectrum, i.e., a redshift of the resonant wavelength from 4.25 to 7.07 µm with a tuning range of up to 2.82 µm for MPA‐丰 and from 4.14 to 7.09 µm with a tuning range of 2.95 µm for MPA‐木. Furthermore, MPA‐丰 realizes the resonance transition between single‐and dual‐resonance. The physical mechanisms allowing wavelength shifts and absorption intensity variations are uncovered through in‐depth electromagnetic field analysis. Additionally, by switching the incidence from transverse electric (TE) to transverse magnetic (TM), MPAs exhibit modulable resonant intensities. MPA‐丰 exhibits the triple‐resonance at the wavelength of 4.15, 4.87, and 8.00 µm in TM mode. The above‐mentioned results highlight the promising applications of the proposed MPAs inspired by oracle bone script in optical switching, gas sensing, and filtering, which provide a dynamic approach to spectral modulation in the MIR range.