Moth-eye effect

The book b ins with a chapter that describes certain functions of the skin which contributes to the new area of bio-inspired design. The next four chapter have more specific subjects with its technological applications. Chapter 2 analyzes the shark skin effect or the commonly known antifriction surfaces. Chapter 3 discusses the Lotus effect or the usually known self-cleaning surfaces. Chapter 4 analyzes the Moth-eye effect or the commonly known antireflection surfaces and Chap. 5 describes the Gecko effect or the usually known dry adhesive surfaces. 

Ideally, the surface of the transparent cover should have a gradient of the index of refraction ranging from 1.0 for air to the index of refraction of the cover material. For the required very small indices of refraction no materials exist in nature. Such small indices of refraction can only be made by effective media in which the cover material is mixed with air on a subwavelength scale as described in Sect. 1. Subwavelength surface-relief structures with a continuous profile as shown in Fig. 2 form an effective refractive index gradient and are therefore well suited for broadband AR surfaces. This type of AR surface-relief grating is called a moth-eye structure according to the example found in nature on the cornea of... 

Some literature sources go so far that according to them all subwavelength antireflection reliefs with a gradient of effective refractive index are called moth-eye structures (e.g., [193]), including 2D pyramidal and nanopillar arrays. 

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