Researchers at the University of Pennsylvania have made the ‘magic carpet’ effect come alive by levitating two small plastic plates using just light! Let’s see how they managed to achieve this feat.
Crux of the Matter
What Did They Do?
Using the energy from a set of bright LEDs in a vacuum chamber, the 2 tiny Mylar plates hovered in the controlled environment.
What Is A Mylar Disk?
The Mylar disk is a transparent material, 50x thinner than normal household plastic wrap. The surface was layered with rod-shaped carbon threads, which were the breadth of human hair.
What Happened Next?
The carbon threads absorbed light, and the nanotubes warmed up. Gas molecules heat up from underneath the surface faster than those rising from the top, creating a dynamic lift force.
What’s This Light-induced Flow?
Also called Photophoresis, it allows small particles suspended in gas (aerosols) or liquids (hydrocolloids) to migrate when illuminated by an intense beam of light.
Why Is This A Breakthrough?
Scientists had levitated invisible aerosols and particles in micro-fluids till now. But they haven’t caused that large an object to float before, using just light. “When the 2 samples lifted, there was a gasp between all 4 of us,” Mohsen Azadi, UPenn engineering doctoral candidate.
What Does This Mean?
Researchers can now study the mesosphere, by developing a flight system that will carry tiny sensors, using the light-powered hovering tech.
What Is The Mesosphere?
It is the third layer of the atmosphere (50-85 km above our planet), and is the coldest atmospheric layer surrounding the earth.
What About Hovering Over Mars?
NASA can use this tech in Mars research for collecting temperature and composition data. This is possible because the pressure in the Red Planet’s atmosphere is similar to Earth’s mesosphere.
- Mesos means ‘Middle’ in the Greek language. Hence, Mesosphere literally means the middle layer of the atmosphere.
- Atmospheric circulation is the large-scale movement of air and together with ocean circulation is the means by which thermal energy is redistributed on the surface of the Earth. The Earth’s atmospheric circulation varies from year to year, but the large-scale structure of its circulation remains fairly constant.
- The Kármán line is an attempt to define a boundary between Earth’s atmosphere and outer space. This is important for legal and regulatory measures; aircraft and spacecraft fall under different jurisdictions and are subject to different treaties. The line is named after Theodore von Kármán, a Hungarian American engineer and physicist, who was the first person to calculate the altitude at which the atmosphere becomes too thin to support aeronautical flight and arrived at 83.6 km himself.