For more than 25 years now, a quiet little design lab at Harvard has been working on a unique robotics project — perfecting the world's first and only RoboBee.

Research published Oct. 25 in the journal Science Robotics details the latest iteration of the little bot, which was first conceived by mechanical engineering student Robert Wood in 1991. Since then, the RoboBee project has been a perennial work-in-progress for scientists and students at the Harvard School of Engineering and Applied Sciences and the Wyss Institute for Biologically-Inspired Engineering.

Even in its most basic configuration, the RoboBee is a mechanical marvel. Its tiny polymer wings – designed to mimic real insect wings – are powered by small ceramic “muscles” that convert electrical pulses into kinetic energy, making the RoboBee the world's smallest flapping-wing aircraft.

Every few years, designers officially publish new research on various RoboBee models under development. (One version of the bot can stick to walls, for instance.) This latest version of the RoboBee is the most ambitious yet, as it can fly, dive into water, swim around, and propel out of the water.

Those are tricky maneuvers for any robot, and it's taken years of development to get larger amphibious drones to manage the trick. But because the RoboBee weighs in at a featherweight 175 milligrams (0.006 of an once), the tiny machine must actually overcome forces of mass, volume, and surface tension that are completely different than what a bird-sized robot has to deal with. It also requires a multi-modal locomotive system that lets the bot both fly and swim.