Separating mechanism of dandelion (Taraxacum officinale) seed: Results from model analysis and separation force measurement

Abstract Dandelion seeds can be elegantly released by a gentle wind, but their separating mechanism has not been revealed. Here, we investigated the separating mechanism via structure observation, model analysis and separation force measurement. Connecting region of a dandelion seed includes barbs distributed on the inserting region of achene and groove of the inflorescence head. The barbs have conical morphology with a length of 42–50 μm, and the groove has plenty of wrinkles to enhance its wrapping ability. Based on structure characteristics of the connecting region, we established a model to analyze the mechanical properties produced by barbs and wrinkles during their separation. Model result confirmed that the barbs in different part of the inserting region have considerable difference in degree of separation difficulty, and the calculated separation force decreases sharply when the separation angle increases from 20° to 80°. The measured separation force (10.69–0.35 mN) showed almost the same change tendency as the calculated separation force, confirming the validity of our established model. Our study reveals the separating mechanism of dandelion seeds, and provides an approach for the biomimetic design of controllable attachment/release device used in the field of mechanical engineering.