Shape Control of Lotus Leaf Induced by Surface Submillimeter Texture

Automatic slant of lotus leaf achieving self-motive unidirectional fluid transport is significant for self-cleaning, decreasing load, enhancing respiration, and receiving more sunlight, which is the consequence of natural evolution. In this study, the mechanism of the automatic gradual slant process in its development is exposed and this function is successfully replicated. The special distribution of submillimeter papillae (SP) on the leaf surface generates anisotropic deflection and induces the leaf edge to warp asymmetrically. These effects shift the center of gravity, slant the leaf, and bend the petiole gradually, thereby guiding the liquid away from the surface with synergy effect. The behaviors of lotus leaf are realized with stimulus of temperature on artificial lotus leaf. This work uncovers a new theory for shape control of soft materials and opens up new horizons for artificial intelligence, flexible robot, flexible sensor, and membrane manufacture industry.