What is a riblet?

A riblet is a small, ridged and tapered piece of material, typically made of plastic or metal, which is attached to the surface of an object, such as an aircraft wing or boat hull. Riblets have been found to reduce drag and improve the aerodynamic efficiency of a surface by modifying the way in which air flows over it, leading to reduced fuel consumption and increased speed. The idea for riblets originated in nature, where they are observed on the skin of sharks. Scientists have studied the structure of these natural riblets to create synthetic versions for use in engineering applications.