MIT grads Lisa Burton and Nadia Cheng have developed a series of alcohol-fueled boats that cruise around cocktails.

Their simple vessels were filled with alcohol, which seeps out of a slit on one side. The difference in surface tension creates a propulsion effect.

"We did a ton of 3-D printing to optimize the geometry of the components to make them work," says Cheng.

"Like designing the slit in the back of the boat to enable slower 'fuel' leakage so that the boat can operate for longer periods," says Cheng.

They discovered the shape of the boat, while important, was overpowered by the alcohol content of the fuel.

Higher octane hooch helped the boats move faster, and top-shelf spirits let them reach top speeds of four inches per second.

"We could make almost any shape work," says Cheng. "The rubber ducky was just fun. I love miniatures."

Leveraging their understanding of buoyancy and drag, Cheng and Burton worked out the key mechanics—how much liquor the vodka-fueled vessels required, the optimal size of the gap that powered them. They were ultimately able to move on to aesthetic challenges.

Cheng and Burton recently graduated, but the project lives on, and chocolate versions of the boats are in development in a partnership between Andrés and the Mars candy company.

Cheng calls the process of fabricating the flower "capillary origami" and started prototyping petals made from silicone, which were then attached to 3-D printed stems.