Levitating solar-powered micro flyers may fly high where planes and rockets can't

A new solar powered micro flyer technology may be key to exploring a part of the atmosphere that planes and spacecraft can't visit.

A team from the University of Pennsylvania have tested the devices in the lab, which use a phenomenon called "photophoresis" to fly powered only by light energy.

The six millimetres diameter disks are small sheets of super light and transparent mylar plastic that have been coated on one side with carbon nanotubes. Light passes through the mylar and is absorbed by the nanotubes, which then heat up.

Molecules of air encounter the flyer and become temporarily tangled in the nanotubes, where they in turn are heated up. As they escape, they provide a recoil force that pushes the flyer upwards.

Igor Bargatin, an associate professor in the Department of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania, told Bob McDonald that the technology seems well suited to exploring the mesosphere, the portion of the atmosphere between 50 and 85 kilometres up.

This air in this part of the atmosphere is so thin that airplanes can't reach it, but is too thick for orbiting spacecraft to fly through. Experiments at comparable air pressures in the lab, however, suggest Bargatin's flyers, seem to work well in this environment.

Because of the diminutive size of the devices, they would carry a very small payload of microelectronic sensors. Bargatin, however, thinks it may be possible to scale the devices up to carry more significant loads. 

Produced and written by Jim Lebans