researchers have invented a way to keep any metal surface free of
ice and frost - a discovery that will prove beneficial in
refrigeration systems, wind turbines and the construction
The surfaces treated with the chemical quickly shed even tiny,
condensation droplets or frost.
The technology prevents ice sheets from developing on surfaces -
and any ice that does form, slides off effortlessly. The discovery
has direct bearing on a wide variety of metal surfaces such as
those used in refrigeration systems, wind turbines, aircraft,
marine vessels, and the construction industry.
The group, led by Joanna Aizenberg, professor of materials science
at the Harvard School of Engineering and Applied Sciences (SEAS),
previously introduced the idea that it was possible to create a
surface that completely prevented ice with ice-repellent coatings,
inspired by the water repellent lotus leaf, the journal ACS Nano
Yet this technique can fail under high humidity as the surface
textures become coated with condensation and frost. To combat this
problem, researchers recently invented a radically different
technology that is suited for both high humidity and extreme
pressure, called SLIPS (Slippery Liquid Infused Porous Surfaces).
"Unlike lotus leaf-inspired icephobic surfaces, which fail under
high humidity conditions, SLIPS-based icephobic (non-stick)
materials, as our results suggest, can completely prevent ice
formation at temperatures slightly below zero degree Celsius while
dramatically reducing ice accumulation and adhesion under deep
freezing, frost-forming conditions," said Aizenberg.
The challenge was to apply this technology to metal surfaces,
especially as these materials are ubiquitous in our modern world,
from airplane wings to railings, according to a Harvard statement.
Aizenberg and her team developed a way to coat the metal with a
rough material that the lubricant can adhere to. The coating can
be finely sculpted to lock in the lubricant and can be applied
over a large scale, on arbitrarily shaped metal surfaces. In
addition, the coating is non-toxic and anti-corrosive.
Researchers successfully applied the technology to refrigerator
cooling fins and tested it under a prolonged, deep freeze
condition. Compared to existing "frost-free" cooling systems,
their innovation completely prevented frost far more efficiently
and for a longer time.