Following 100 years of flight, drones are making us question everything we know about aircraft. Sure, most military drones still resemble pretty typical planes, but we're also seeing all sorts of alternative approaches to flying, like tiny quadcopters that can perform remarkable acrobatics no stunt pilot could dream of. Without human payloads on the line, relatively low-cost drones are spearheading a mass wave of experimentation in flight.
Case in point is the work of NYU postdoc Leif Ristroph, a mathematician, physicist, and self-ascribed tinkerer who has led a team to create what many have compared to a flying jellyfish. Truth be told, its herky-jerky flight path is probably more reminiscent of a butterfly or moth, but that point is a bit irrelevant to Ristroph. He never created the drone to biomimic organic life of any sort, but actually to improve upon nature’s existing flight models to shrink drones to smaller sizes than they’ve ever been before.
So how’d he do that? He used his understanding of math and physics to create a robot with the aerodynamics to fly without a brain.
“Helicopters and insects rely on specialized sensors and feedback control systems to keep upright, “Ristroph tells Co.Design. “My main goal here was to make a flapping-wing device that could hover just by using its wings--no sensors or feedback control (no "brain") and no extra tails, sails, or other aerodynamic surfaces. There's something elegant about finding the simplest possible flyer.”
Indeed, Ristroph’s drone weighs just 2 grams, as it’s constructed of mere plastic and carbon fiber, but it can fly mindlessly, easily ride a breeze, and still manage a modest payload of 1.5 times its own weight. With such simplistic internals, the drone is a prime candidate to scale down to extremely small proportions. In an upcoming paper, Ristroph will reveal just how tiny he believes his drone can shrink, but his single caveat may tip his hand a bit: Engineers would need to to build motors small enough to take on the challenge, first.
Meanwhile, Ristroph won’t be waiting around. He intends to let others take on the task of iterating his jellyfish drone, while he pursues more, new methodologies of flight. As for where his creation ultimately ends up, “In terms of applications, there is obviously a lot of military interest,” he writes, “but I like peacetime uses, such as for monitoring air quality above a city or general search-and-rescue.”