A micelle is the self assembled sphere formed from surfactants in a hydrophilic liquid such as water. It is formed when surfactant hydrocarbons that have a hydrophilic charged head group and a long hydrophobic tail aggregate. The hydrophobic tails are attracted to each other and try to get out of their hydrophilic environment by bunching up. This leaves the hydrophobic heads pointing outwards where they are content in their environment. Micelles are often spherical, however they can be elliptical as well.
Velcro is used any time two things need to be temporarily fastened together. For normal use it is seen in shoes, jackets, and gloves. However there are much more exotic uses of Velcro as well. NASA uses velcro in space for many different applications. For example the astronaut space suits are fastened with velcro. Also, when sitting down the astronauts attach themselves to the chair with velcro.
A research group in Korea is attempting to make a nano sized equivalent to velcro. They have produced and published a paper called Shape-Tunable Polymer Nanofibrillar Structures by Oblique Electron Beam Irradiation that discusses their research.