Fig. 1. The number of published papers on “tunable metasurfaces” from Web of Science in the past decade. Search keywords：tunable/dynamic/reconfigurable/active metasurfaces

Fig. 2. Electrically tunable metasurface of ITO combined with plasmonic effect

Fig. 3. Dual-gated ITO metasurface and tunable ITO/dielectric metasurface

Fig. 4. Graphene-based electrically tunable metasurface

Fig. 5. Schematic of the photonic crystal integrated with MoS₂ controlled by photochemical modulation and optoelectronic modulation，which can adjust the real and imaginary parts of the complex refractive index ±0.2 ^［53］

Fig. 6. Electrically tunable metasurfaces of TMDs/metallic structures

Fig. 7. Electrically tunable plasmonic metasurface based on III-V semiconductors

Fig. 8. MQW-based electrically tunable metasurface

Fig. 9. Liquid crystal based electrically tunable metasurfaces

Fig. 10. Electro-optic crystal based electrically tunable metasurfaces

Fig. 11. MEMS-based metasurface functional devices