For 13 years now, a Dutch research team has been building autonomous flying robots inspired by the humble fruit fly. Now, with the DelFly Nimble, they've achieved their closest mimic yet, with an incredibly agile fly-bot capable of multi-axis hovering and even turning flips.

Nature sure has come up with some insanely efficient and useful designs over its billions of years of trial and error, and evolution still has a ton to teach us as we press forward into the technological age. The DelFly project, run out of the Micro Air Vehicles (MAV) lab at the Delft University of Technology in the Netherlands, has been working since 2005 to build an autonomous robot that can copy the movements of a fruit fly.

Within three years, the team had built the world's smallest camera-carrying MAV, in 2008's DelFly Micro, which weighed just 3 g (0.1 oz) and had a 10-cm (3.9-in) wingspan. By 2013, the team had built the first fully autonomous flapping-wing MAV, the DelFly Explorer, but in order to control it they had to augment the fruit fly design with some more traditional plane-like control surfaces and a tail.

Five years later, the team has managed to get rid of the tail and control surfaces to build the closest thing yet to a robotic fly, and boy, can this thing move. The DelFly Nimble measures 33 cm (13 in) across its wings and weighs 29 g (1 oz). It has double wings on each side, made from transparent Mylar foil, which flap in and out of an X shape.

The key advance here is that the Nimble is able to rotate the axis of the bottoms of its wings, creating a yaw effect to go with the existing pitch and roll control. That gives it exceptional agility to go with its zippy 25 km/h (15.5 mph) top speed.

Thanks to a thrust-to-weight ratio greater than 1.3, the DelFly Nimble is capable of carrying a small payload if you want to put sensors or cameras on it. And as well as beginning to look very much like a fly in motion, it's also able to pull off some aerobatic tricks, including the same kinds of rapid banked turns fruit flies can make when they're evading predators, and the odd backflip.

What's this all in aid of? Well, the team sees flapping-wing MAVs like the DelFly as a possible replacement for multicopter style drones, citing their light weight, more efficient use of energy, and the fact that a flapping wing is safer around humans than a rotating blade.

Check out the DelFly Nimble in a video below.

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