Fig. 2: Curvature and long tail of artificial bodhi-leaf reshaped drop separation centroid and enhanced water drip frequency.
From: Efficient agricultural drip irrigation inspired by fig leaf morphology
a Optical image of PET-based biomimetic bodhi leaf with shape parameters R, r, Wbase, Lapex, and Wtip noted from top to bottom. Reverse curvature, r/R, controls convergence region and long tail, Lapex/Wbase, controls drainage region. Insets are the contact angle of a water droplet on the PET surface and scanning electron microscopy (SEM) images of the PET substrate in the central part and at apex tip. b Scheme of the three-needle experimental setup. c, d Effect of the reverse curvature r/R on the aggregation of water flow. c Oblique and side views of water flow dynamics on artificial bodhi leaf with r/R = 0.618 (the golden section point) where water drop separates beyond the artificial leaf apex, and r/R = 0.238 where water drop separates above the leaf apex, at the same injection flow rate Q of 32.0 mL min−1. Red arrows in the oblique views indicate water flow direction, and red dots in the side views indicate the centroid of the newly forming drop near the apex tip. d r/R accords with the Fibonacci sequence and ranges from 2/21 to 21/21. e Water drainage frequency f of various r/R values at 8.0–36.0 mL min−1 and β = 30°. The light-blue and mint-green dashed curves denote Above-drip and Beyond-drip states. f Scheme of the single-needle experimental setup. g Long-tail Lapex/Wbase ranges from 2.5 to 15.0. h Water drainage frequency f of various Lapex/Wbase at 4.0–16.0 mL min−1 and β = 30°. Note that some error bars are smaller than the symbols. The red dashed lines in (e) and (h) were linear fitting of corresponding data points. Data in (e) and (h) are shown as mean ± SD, and the error bar represents SD (n = 3 independent experiments). Source data for (e, h) are provided as a Source Data file.
