For the fuel, Burton originally tried everything from her kitchen that might work: soy sauce, sugar water, Tabasco, different liquors. She discovered that an evaporative fluid with low surface tension was ideal. Liquors performed far better than anything else, especially strong ones like Bacardi 151, which is 75 percent alcohol.
The trick with the boats was to make them light enough to float on water and durable enough so that they wouldn't decompose in the water. Burton tried different materials including mixtures of candies, marshmallows and other food. They tasted good but didn't function as well as those made from just wax or gelatin. "The boats made of wax worked great, but were as tasty as flavorless wax can be," she told me.
Edible Gold Sensors Alert to Spoiled Food
Through John Bush, Burton and Cheng connected with science-minded chefs José Andrés, César Vega and the D.C.-based ThinkFoodGroup. In addition to the boats, the team also made an edible flower-inspired pipette that can be used as a clever way to deliver a modest liquid palate cleanser between dishes. This month the group published their results in the journal Bioinspiration & Biomimetics (abstract).