Solar Powered Aerial Vehicles
Solar Powered Aerial Vehicles
Using only sunlight to create lift force, these aerial vehicles can levitate without any moving parts, even at altitudes where the air is too thin for airplanes and balloons.
This technology uses nanomaterials to demonstrate light-powered levitation of microflyers. For the first time, we devised macroscopic objects that can fly without any moving parts using photophoresis, or light-induced airflow. This new flight mechanism will enable 1) sunlight-powered meter-scale vehicles in the upper atmosphere collecting information about our changing climate and 2) millimeter-scale photophoretic microflyers that will surround us on Earth’s surface, providing ubiquitous sensor data.Historically, flight has been achieved using balloons, propellers or flapping wings, or rockets but all these technologies “hit a wall” at some point. For example, rockets can fly no more than about 10 minutes per stage, while balloons and airplanes cannot rise about the stratosphere, with altitude records maxing out at ~50 km. In addition, balloons, propellers, or flapping-wing flyers must be a few centimeters or larger to work. Despite the commonly used name “microflyers”, no man-made structures of less than 1 cm can fly sustainably due to the increased effects of viscosity at small sizes.Using photophoresis as a completely new physical mechanism to fly, we can break through these walls. Large photophoretic aircraft can fly at altitudes of 50 to 100 km using only sunlight, finally enabling long-term studies of the mesosphere. Different physics also means that photophoretic microflyers work better as their size decreases, finally allowing the creation of true microflyers (< 1 mm).
About the Lab
The Bargatin group pushes the limits of nanofabrication techniques to create materials and structures with unprecedented mechanical properties and to enable applications such as heat-to-electricity direct energy conversion, new levitation techniques for microflyers, and interstellar travel using a lightsail (also known as project Starshot). We recently invented plate mechanical metamaterials, creating the thinnest plates that can be picked up by hand as well as nanocardboard – the nanoscale analog of corrugated cardboard and other sandwich composite plates. We design and test new types of energy devices, such as microfabricated thermionic energy converters, which convert heat directly to electricity at very high temperatures by literally boiling electrons off a surface and using them as a “working fluid” in a heat engine. Finally, we are studying new methods of levitation and propulsion without moving parts.
POPULAR SCIENCE ARTICLES
ScienceNewsExplores; Light levitation might help explore Earth’s ‘ignorosphere’
Penn Today; A New Way to Fly, Built Up From the Nanoscale
ORIGINAL RESEARCH PAPERS:
Applied Sciences and Engineering; Controlled levitation of nanostructured thin films for sun-powered near-space flight
Advanced Materials; Photophoretic Levitation of Macroscopic Nanocardboard Plates