Reconfigurable Spoof Plasmonic Skyrmion Electronics for Deformation-Invariant Multimode Sensing.

The advancement of wearable electronics is often hindered by motion artifacts and miniaturization constraints, especially in dynamic physical environments such as skin interfaces. To address these challenges, we introduce a flexible multimode sensor based on reconfigurable spoof localized surface plasmon (SLSP) skyrmions with integrated multi-capacitor loading. This design achieves tight compression of all equidistant resonant modes, yielding an ultrahigh quality factor of 164.29 within a deep-subwavelength footprint of only λ/14.5 in diameter. We systematically investigate three distinct topological configurations-circular, square, and heart-shaped-with identical effective skyrmion lengths, and demonstrate that all multi-resonant modes retain consistent frequencies regardless of shape, underscoring exceptional topological robustness. Fabricated on a flexible polyimide substrate, the SLSP skyrmions exhibit remarkable bending stability, maintaining stable resonant responses under various deformation conditions, as validated by both simulation and experiment. Furthermore, through capacitance loading, the average normalized sensitivity of multimodal sensing is enhanced from 2.5% to 3.3% when exposed to materials of different dielectric constants. Our work establishes a new paradigm for motion artifact-free, flexible sensing with ultra-compact form factors and high quality factor (Q-factor), highlighting the significant potential of SLSP skyrmions in next-generation wearable electronic applications, including electronic skin and conformal health monitors.