Natural superhydrophobic surfaces plants

Natural superhydrophobic surfaces [1, 2] as observed with leaves of some plants or feathers of some birds, correspond to hydrophobic surfaces whose water contact angle (0) is higher than 150° [3], Such surfaces are sometimes called self-cleaning surfaces since a water droplets will take up the dirt particles and roll off the surface [2], The values of water contact angles cannot be obtained with real surfaces, as... 

In the present chapter, we will review natural superhydrophobic surfaces, such as plant leaves, bird feathers, insect wings and legs. There after, we will present the theory of superhydrophobicity and will review biomimetic superhydrophobic surfaces. 

Many plant surfaces [46] and animal furs [74] showed water-repellent properties, i.e., larger water CA. With the help of scanning electron microscopy (SEM), the microstructures of plant surfaces exposed show that water repellency is primarily caused by epicuticular wax crystalloids, which cover the cuticular surface in a regular micro relief of about 1-5 mm in height [72], Lotus leaves are one of the most important examples of a naturally occurring superhydrophobic surface [46], The water CA of a lotus leaf is 161 2.7° with CA hysteresis of 2° [75]. Pictures of a lotus leaf and its microstructure image reported by Barthlott and Neinhuis [46] are shown in Figure 17.11. 

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