MIT researchers have developed a completely passive, solar-powered system to prevent ice buildup on airplanes, wind turbines, powerlines, and other surfaces.
Ice buildup are known to cause problems ranging from impaired performance all the way to catastrophic failure.
De-icing helps, but it often requires energy-intensive heating systems or chemical sprays that are environmentally harmful.
The new chemical-free MIT system is remarkably simple as it is based on a three-layered material that can be applied or even sprayed onto the surfaces to be treated.
According to the researchers, the system collects solar radiation, converts it to heat, and spreads that heat around so that the melting is not just confined to the areas exposed directly to the sunlight.
Once applied, it requires no further action or power source. It can even do its de-icing work at night, using artificial lighting.
The new system owes its genesis to MIT associate professor Kripa Varanasi, and postdocs Susmita Dash and Jolet de Ruiter.
“Icing is a major problem for aircraft, for wind turbines, powerlines, offshore oil platforms, and many other places,” Varanasi says. “The conventional ways of getting around it are de-icing sprays or by heating, but those have issues.”
De-icing sprays for aircraft and other applications use ethylene glycol, a chemical that is environmentally unfriendly. Airlines don’t like to use active heating, both for cost and safety reasons.
The new system’s top layer is an absorber, which traps incoming sunlight and converts it to heat. The material the team used is highly efficient, absorbing 95 percent of the incident sunlight, and losing only 3 percent to re-radiation, Varanasi says
The second layer is composed of a spreader – a very thin layer of aluminum, just 400 micrometers thick, which is heated by the absorber layer above it and very efficiently spreads that heat out laterally to cover the entire surface.
The bottom layer is simply foam insulation, to keep any of that heat from being wasted downward and keep it where it’s needed, at the surface.
Image credits and content: The Varanasi Research Group/MIT