Penn Engineers’ ‘nanocardboard’ flyers could serve as martian atmospheric probes

This summer, NASA plans to launch its next Mars rover, Perseverance, which will carry with it the first aircraft to ever fly on another planet, the Mars Helicopter. Penn Engineers are suggesting a different approach to exploring the skies of other worlds: a fleet of tiny aircraft that each weighs about as much as a fruit fly and has no moving parts. These flyers are plates of "nanocardboard," which levitate when light  is shone on them. A "nanocardboard" is made of an aluminum oxide film with a thickness of tens of nanometers and is the ultrathin equivalent of corrugated paper cardboard. One square centimeter of nanocardboard weighs less than a thousandth of a gram and can spring back into shape after being bent in half. (see Penn Engineers Develop Ultrathin, Ultralight ‘Nanocardboard’)