Fig. 1.

Fabricated sample images and the sequential operation of the device. a Coloured scanning electron microscope (SEM) image of the MEMS Fano-metasurface. The unit cell comprises of two SRRs separated by a gap g, where SRR cantilever arms of length s are released at a height h. The unit cell dimensions are depicted in the inset, where p_x: 110 μm; p_y: 75 μm; l: 60 μm; s: 25 μm; w: 6 μm; g: 4 μm; and t: 900 nm. V₁ and V₂ are the input voltage ports to achieve the independent actuation of SRR-1 and SRR-2, respectively. b–d SEM images of the unit cell showing the sequential actuation of SRRs with voltage V₁ and V₂ applied across the two SRRs, where the sequence from (b) to (c) represents the increasing asymmetry (δ) and (c) to (d) represents the decreasing asymmetry configuration