Designed for flight forty-five miles above the Earth’s surface, Harvard SEAS researchers have devised a nanofabricated lightweight structure capable of sunlight-driven propulsion through a process called photophoresis, capable of monitoring one of Earth’s most challenging locations to navigate.
Stretching between 30 and 60 miles above the Earth’s surface, the mesosphere has proven extremely difficult to study, as the altitude is too high for planes and balloons, yet too low for satellites. Achieving regular direct access to this long-out-of-reach portion of the atmosphere could be a major boon to improving weather forecasts and climate model accuracy.
Now, a new breakthrough technology could make it possible, by allowing lightweight structures to reach largely unexplored heights powered by sunlight alone.
Photophoresis
Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), the University of Chicago, and other institutions worked on the project, which was revealed in a new paper published in Nature.
“We are studying this strange physics mechanism called photophoresis and its ability to levitate very lightweight objects when you shine light on them,” said lead author Ben Schafer, a former Harvard graduate student at SEAS, now a professor at the University of Chicago.
Photophoresis is a physical process where gas molecules bounce off of an object’s warmer side more forcefully than its cooler side in extremely low-pressure environments. One such environment is the difficult-to-reach mesosphere.
Hellbound and Down 