Chocolate coatings inspire scienceApril 18, 2016
Inspired by the creation of hollow chocolate pieces such as bonbons or chocolate eggs, a group of researchers from the Massachusetts Institute of Technology (MIT) in collaboration with a team of EPFL in Switzerland, have developed a technique of rapid manufacturing and a theory that predicts with great precision the final thickness of a shell made of a known material given the rheological properties of the material and the geometry of the mold used for the coating.
Since 1600, chocolatiers have been perfecting the art of confectionery. Now, with this technique, you can create thin crubbery shells, which involved drizzling liquid polymer on dome- and sphere-shaped molds such as ping pong balls. They allowed the liquid to coat each mold and cure, or solidify, over 15 minutes. They then peeled the resulting shell off the mold and observed that it was smooth with a nearly uniform thickness throughout. Combining this simple technique with the theory they derived, the team created shells of various thicknesses by changing certain variables such as the size of the mold and the polymer’s density. Surprisingly, they found that the shell’s final thickness does not depend on the volume of liquid or the height from which it is poured onto the mold.