Drones

Drones the size of a fly, presented as a prototype by researchers

Talking about bug-sized drones may sound alarming at first, but at least, in principle, they were designed for a good purpose.

There are times when an unmanned flying machine, because of its size, cannot reach its target. A tiny drone can slip away more easily and avoid collisions.

A joint research team, among professionals from MIT, Harvard and the City University of Hong Kong, recently presented a drone model of these characteristics.

Emulating the flight of mosquitoes, which can be highly acrobatic and resistant during flight, the tiny drones developed by this team can travel long distances and overcome obstacles, including gusts of wind. These traits are difficult to incorporate into flying robots, but MIT assistant professor and member of this research team, Kevin Yufeng Chen, has created a system that comes close to the agility of insects.

Tiny drones, great possibilities

Chen, who is also a member of the Department of Electrical and Computer Engineering and the Electronics Research Laboratory of his university, managed to launch drones the size of an insect, something that was unprecedented at the moment, given the technical difficulties involved. involve its materialization.

With a new class of propellant, developed for this particular invention, drones can better resist wind, despite their reduced mass and volume.

With this precedent presented and tested, Chen hopes that robots will one day be able to collaborate with agricultural tasks, pollinating crops; or industrial tasks, conducting machinery inspections in confined spaces.

The purpose behind the development of this new type of unmanned spacecraft is to expand the possibilities of using this technology, expanding it to new areas of application. In general, drones require wide and open spaces, as they are not agile enough to move in tight spaces or robust enough to withstand collisions.

According to Chen, the challenge of building small aerial robots is immense. Fly-sized drones require a totally different build than the larger ones.

The drones that we know the most, fly thanks to the presence of an engine. In this case, given the size of the drone, a motor that conforms to these measures would be totally counterproductive, judging by the power that it would eventually reach.

The solution to this weakness was found by using instead of a motor, a propeller built with piezoelectric ceramic materials. In particular, they are made of thin rubber cylinders coated with carbon nanotubes. By applying voltage to the carbon nanotubes, they generate an electrostatic force that compresses and lengthens the rubber cylinder, which consequently causes the drone’s wings to move rapidly.

With technology developed by Chen and his team, these tiny drones can flap nearly 500 times per second, giving the drone insect-like resistance.

As additional benefits, these drones can resist blows and recover their trajectories, as well as can perform acrobatic maneuvers in the air.

The mass of this invention is reduced to 0.6 grams, similar to that of a large bumblebee. The prototype presented has an extremely rustic appearance, but a version in the shape of a dragonfly will be presented in the future, according to statements by the principal investigator.

To arrive at this invention, Chen’s team carried out a reverse engineering exercise on the flight of insects, in order to understand the physics behind their movement.

Among the possible applications of this technology is the inspection of complex machinery under circumstances that could be extremely unsafe for people in direct contact. They could also be used in artificial pollination of crops or rescue missions in search missions.

Chen’s work was executed in collaboration with MIT PhD student Zhijian Ren, Harvard University PhD student Siyi Xu, and City University of Hong Kong roboticist Pakpong Chirarattananon.

You can find more details about this interesting development on the MIT website or in a paper published in the journal IEEE Transactions on Robotics, which contains the report of this investigation.

Header image: courtesy of Kevin Yufeng Chen