Tiny, levitating "Nanocardboard flyers" could soon serve as new Mars Probes!!

 A visualization of the "nanocardboard" flyers.

 (Image: © Bargatin Group, Penn Engineering)

   

With the Rapid Advancement of technology, several new innovations are being proposed towards space exploration. 

Amidst all the speculations regarding Terraformation and landing on Mars, this summer, NASA will launch its newest Mars rover, Perseverance, and a helicopter that will fly over the planet's surface as part of a "high-risk, high-reward" experiment. But even before its launch, researchers are designing much more ambitious aircraft for Mars as well.

Of particular interest are flying aircraft that could, with less risk, more effectively observe and study Mars' surface. In a new study, researchers have demonstrated the abilities of a unique fleet of aircraft that could thrive on Mars: tiny "nanocardboard" flying vehicles. These aircraft each weigh about a third of a milligram, or less than a fruit fly, and have no moving parts. Instead of flying with wings or rotating blades, they actually levitate.

Currently in development at the University of Pennsylvania, the small, flat, rectangular devices aren't actually made of cardboard. Instead, they're constructed from an aluminum oxide plate that has groups of slot-like microchannels running through its mostly hollow interior. These boost its bending stiffness, keep cracks from propagating, and give it a corrugated cardboard-like structure.

They also allow it fly.

When the top surface of the plate is heated by exposure to bright light, the temperature differential between it and the plate's shaded underside causes air to be drawn in through the open top of each channel, and expelled out through its open bottom. This creates a cushion of air beneath the Flyer, levitating it.

It may even be possible to steer them, though close to the ground. If one of the tiny aircraft were to be deployed from a ground-based rover, that vehicle could conceivably track the Flyer with a laser, turning it by selectively shining the laser on different areas of its plate's top surface. Utilizing multiple independently controlled lasers, it's even possible that a single rover could control a whole fleet of Flyers.

This strange method of flight would be particularly advantageous on Mars because the planet's thin atmosphere and weaker gravity would allow the plates to lift more weight and travel over much longer distances than here on Earth.

Researchers tested the "nanocardboard" flyers in a "Mars-like" environment in lab.
(Image credit: Bargatin Group, Penn Engineering)

In a study, the researchers tested "nanocardboard" vehicles in a Mars-like environment in a lab environment. They tested the vehicles in a low-pressure test chamber and experimented with mock payloads by having the little floating plates carry silicone rings. 

 Additionally, Bargatin is working with other researchers to develop new, tinier chemical sensors that could collect important data and detect substances like methane and water on other planets, according to the statement - 

"In addition to carrying sensors," Bargatin said, "our flyers could simply land and have grains of dust or sand passively stick to them, then transport them back to the rover so it doesn't need to travel as far."

Bargatin also suggested in the statement that fleets of these tiny flyers could be used to study our own planet's atmosphere — specifically, the mesosphere.

"The Earth's mesosphere is pretty similar to the Martian atmosphere in terms of density, and we currently don't have anything that flies there, since it is too low for space satellites but too high for airplanes and balloons," Bargatin said. "Ideally, you'd like to have some sensors up there as well. The more knowledge you have about the movement of the atmosphere at that level, the better predictions you can make about Earth's climate and even weather."

The research was published Tuesday (April 21) in the journal Advanced Materials.