Ultra‐Broadband Terahertz Flexible Meta‐Absorber

ABSTRACT Terahertz (THz) metasurface absorbers have emerged as a promising platform for electromagnetic wave manipulation owing to their compact footprint, structural versatility, strong light‐matter interaction, and near‐unity absorbance, enabling applications in sensing, imaging, stealth technology, and wireless communications. However, simultaneously achieving ultra‐broadband absorbance, mechanical flexibility, angular stability, and active tunability within a single metasurface platform remains challenging, and often requires complex designs and fabrication processes. Here, we experimentally demonstrate an ultra‐broadband THz meta‐absorber based on a metal‐dielectric‐metal (MDM) architecture employing a structurally simple arc‐shaped aluminium structure integrated on a flexible Kapton substrate. The fabricated device exhibits experimentally measured broadband absorbance exceeding 90% over the broad frequency range of 0.54–1.10 THz. Furthermore, the absorber maintains excellent performance under different bending curvatures and oblique incidence, demonstrating outstanding mechanical robustness and angular stability, making it compatible for integration with curved surfaces. Numerical investigations further reveal efficient thermal tunability through the integration of phase‐change material vanadium dioxide (VO 2 ). Our proposed flexible meta‐absorber combines ultra‐broadband absorbance, mechanical robustness, angular stability, and active tunability within a compact and fabrication‐friendly platform, making it a promising candidate for next‐generation THz sensing, imaging, stealth technology, wireless communications, and adaptive photonic devices.