In 2013, Harvard University’s School of Engineering and Applied Sciences started the “RoboBee” project. At the time, it was impressive enough for a drone to take off, fly, and land without issue. Submerging an unmanned aerial vehicle in water seemed ludicrous, even like a completely unnecessary capability. Since then, we’ve seen drones that can stick to walls, dive in and out of the water, and more. The RoboBee project has kept up with these advancements, capably doing all of the above, with the newest model being able to swim and shoot back out into the skies.
According to The Verge, the RoboBee weighs a mere 175 milligrams—that’s 0.006 ounces. While the RoboBee is incredibly lightweight, its surface area still makes it difficult to submerge and re-emerge from bodies of water. Reportedly, the surface tension required is ten times RoboBee’s weight, and three times the lifting power.
“The force from surface tension feels like an impenetrable wall,” said Harvard professor of engineering, Robert Wood.
So how did Harvard’s engineering and applied sciences researchers get this UAV to seamlessly dive in and out of water? The answer, though simple in its physics, is still quite exciting.
The engineering team fitted the RoboBee with a miniature rocket that combusts to propel the drone out of that high surface tension, breaking it out of the water. Reportedly, a chamber within the RoboBee is filled with gas and lit by an internal spark, causing the forceful eruption that shoots the drone in one direction. The interesting thing here, though, is that the aforementioned gas is the result of small electrolytic plates within the drone converting the water into oxyhydrogen. In other words, the explosive gas was created by the water that surrounds the submerged drone.
Let’s take a look at Harvard’s own video summary of their new RoboBee.
Former versions of the RoboBee, which were incapable of this impressive aquatic feat, didn’t require all of this internal gear. Therefore, a redesign was in order, to fit the gas chamber and four buoyant pieces that keep the UAV afloat within water, as opposed to sinking completely.
The new RoboBee model can fly, land in water and traverse its surface, and shoot back out to the skies. However, as of yet, it can’t be controlled remotely, and there’s no room in its current design for any other sensors or a sophisticated guidance system. After following this project for the past few years, though, it’s clear that this is a continuing project that keeps building upon its previous successes. Surely, the next time we report on the RoboBee, it’ll be capable of even more impressive abilities.