Fig. 3: Photo-tuning in autorotation behavior inside the wind tunnel.

a Schematic drawings of the rotary seed inside the vertical wind tunnel. b Superimposed picture of the height changes of the artificial seed by increasing upward wind flow from 0.8 m s⁻¹ to 1.2 m s⁻¹. c The changes of the height (h, red ring) and spinning rate (Ω, blue dot) of the artificial seed by increasing the wind speed. The error bars are displayed as mean values +/- standard deviation (n  =  3). The same sample was measured repeatedly. d Snapshots of height changes of a non-responsive (left) seed and a responsive (right) one upon UV exposure (150 mW cm⁻²). e The changes of h (blue ring) and Ω (red dot) of non-responsive and responsive seeds upon 150 mW cm⁻² UV excitation. f The maximal recorded changes of the height Δh_m (red ring) and the spinning rate Ω (blue dot) of the artificial seed at different UV irradiation intensities. The error bars are displayed as mean values +/- standard deviation (n  =  3). The same sample was measured repeatedly. The wind speed is 1.1 m s⁻¹. g The snapshot images of an artificial seed with reversible height change by altering the illumination between UV and visible light sources. UV: 360 nm, 150 mW cm⁻²; visible light: 460 nm, 400 mW cm⁻². h The changes of h (red line) and Ω (blue dot) of the artificial seed upon changing the excitation wavelength. All scale bars are 1 cm.