Finding a bug in your drink is no one's idea of a pleasant surprise. But a renowned chef and a team from the Massachusetts Institute of Technology hope that a fanciful cocktail accessory modeled after an aquatic insect will delight rather than repulse.
The tiny, boat-shaped gadget propels itself around the surface of a beverage for up to two minutes using a trick borrowed from nature. The boat contains a potent liquor, which it steadily dispenses into the cocktail through a notch at one end. The difference in alcohol content between the two liquids creates a gradient in surface tension, propelling the boat forward via a phenomenon called the Marangoni effect. Many aquatic insects rely on Marangoni propulsion—but instead of spewing Bacardi 151, they release chemicals that modify the surface tension underfoot.
The gizmo came into being after M.I.T. applied mathematics professor John Bush attended a talk by chef José Andrés, who lectures on the science of cooking at Harvard University. Bush suggested that they collaborate on novel culinary designs. “Much of my research concerns surface tension,” Bush says, “which is responsible for a number of interesting effects that arise in the kitchen—or the bar.”
The researchers also designed a flowerlike pipette that a diner can dip into a palate-cleansing cocktail to carry a droplet to his or her tongue. The pipettes fold their petals shut when pulled out of the liquid, trapping a droplet inside. The device inverts the design of floating flowers such as water lilies that close up to trap a pocket of air when water levels rise. Bush, Andrés and their colleagues described the designs in the journal Bioinspiration & Biomimetics.
Using a 3-D printer, the researchers prototyped the gadgets and then produced molds so that Andrés and his team could make boats and pipettes out of gelatin or candy. “The designs are to be not only functional and aesthetically pleasing but edible,” Bush says.