Available Technology
Microstructured surfaces that prevent ice accumulation
Technology:
Structured surfaces and methods of preventing ice accumulation
Markets Addressed
Undesired ice accumulation can lead to significant economic losses as well as loss of life. The market for preventing ice formation is very large. The ordered superhydrophobic surfaces of this invention have potential applications in various areas of industry, notably as anti-icing coatings on airplane wings, building exteriors, windshields, outdoor signs and electrical wires.
Innovations and Advantages
Professors Joanna Aizenberg of Harvard and Tom Krupenkin of the University of Wisconsin at Madison and their colleagues have invented a new method for using a microstructured, non-wetting surface to prevent ice formation on the surface.
Current anti-icing technologies involve either the use of mechanical removal of ice (i.e. pneumatic wings), chemical coatings (i.e. chemical sprays), or input of heat. They found that superhydrophobic surfaces, such as an ordered array of microposts, are able to prevent ice accumulation over extended time periods without any input of heat or mechanical force. The surfaces are passive, and can be reproduced from inexpensive materials, such as polymers which could be formed into large area sheets. Also, they have the advantage of designing their surfaces as ‘closed-cell’ structures to possess various properties such as increased mechanical strength, pressure stability, anisotropic dewetting, and low thermal conductivity. The figure below shows a brick patterned closed-cell microstructured surface, typical dimensions are h = 10 micron, l and w are 25 micron and t = 5 micron.
They have found that water droplets impacting their designed microstructured superhydrophobic surfaces have a limited contact time with the surface. Even under ice-forming conditions, droplets impinging cold superhydrophobic substrates bounce off the surface before freezing can occur.
These kind of surfaces can be made by either imprinting a textured pattern into a hydrophobic surface, or by laying a polymer film containing the pattern onto the surface. The figure below shows a potential industrial method of making such films. There are a wide variety of such superhydrophobic, non-wetting surfaces that could be used in the novel method of this technology.
Additional Information
Intellectual Property Status: Patent(s) pending
Press:
Breaking the ice before it begins
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Inventor(s):
Aizenberg, Joanna
Hatton, Benjamin D.
Krupenkin, Tom
Mishchenko, Lidiya
Taylor, Joseph Ashley
Categories:
For further information, please contact:
Laura Brass, Director of Business Development
(617) 495-3067
Reference Harvard Case #3573