With research that will make you wish you had studied a little harder in high school science class, engineers at MIT have revealed some delicious-looking experiments. The latest batch of research at MIT hopes to better predict how thick the shell produced by a liquid coating will be. Inspired by master confectioners, who use melted chocolate to coat the inside of a mould, engineers were able to derive a specific formula that accurately predicts the thickness of a shell created by drizzling a liquid polymer solution over a dome-shaped mould.
Based on their data, the researchers developed a simple formula to estimate the final thickness of a shell, which essentially equals the square root of the fluid's viscosity, times the mould's radius, divided by the curing time of the polymer, times the polymer's density and the acceleration of gravity as the polymer flows down the mould.
In simpler terms, it takes more time for liquids to flow around a larger mould, resulting in a thicker shell. But if the liquid takes a longer time to harden, more of the the fluid will eventually drain off the mould resulting in a thinner shell.
In addition to possibly revolutionising the chocolate bunny industry, the research will eventually make it easier to precisely customise the thickness of the shells on pharmaceutical capsules for more effective delivery of medications. It even has the potential to change how aeroplane or rocket fuselages are created. Perhaps most importantly, it might also help ensure that one day all chocolates melt in your mouth — not in your hand.