Method of manufacturing closed-cell surfaces with advanced drag-reduction properties

Abstract

A method of manufacture comprising forming a plurality of cells on a substrate, wherein each of the cells has at least one dimension that is less than about 1 millimeter and is configured to hold a medium therein, and wherein each of the cells has walls that laterally enclose an area of a surface of the substrate and has a top opening. The method also comprises contacting the cells with a fluid and introducing a surfactant and a medium into the fluid to thereby form a foam layer contacting the walls of cells. Bubbles of the foam layer have fluid walls that include the surfactant, the bubbles are filled with the medium, and the bubbles remain substantially stationary on the top openings of the cells for a period on average of at least about 1 minute.

Dependencies are inferred from the claim text.