Changing face of flight

Chameleon-like lubricating coatings are being developed that could enable future aircraft and space vehicles to perform more effectively under a wide range of extreme conditions.

Chameleon-like lubricating coatings that react to their environment are being developed that could enable future aircraft and space vehicles to perform more effectively under a wide range of extreme conditions.

The project, a joint effort between New York State’s Rensselaer Polytechnic Institute and the University of Florida, has received $2.5m (£1.4m) of funding from the US department of defence.Prof Linda Schadler, who is heading up the Rensselaer team, explained that vehicles travelling from Earth’s warm and humid environment into the extreme cold vacuum of space require lubricants that can perform under a great range of conditions.

‘These coatings need to operate in the ambient conditions of Earth as well as the extreme conditions of space, for instance at both 1atm and in a vacuum, at high and low temperatures and under differing levels of radiation,’ she said.

Schadler’s team is therefore working to create a number of multifunctional coatings that provide low friction and high resistance to wear in multiple environments. She said that they are looking into the development of both materials that react to their environment and those that are able to tolerate wildly varying conditions.

She explained that the coatings will be made from combinations of thin layers of carbon nanotubes, polymers, and ceramics that can reduce the rate of wear by 1,000 times or more. ‘We have already demonstrated a 1,000-fold decrease in wear rate in nano-filled PTFE and have tested the tribology of nanotube/polymer thin films,’ she claimed.

The new coatings are intended to support the operation of several systems for aircraft and spacecraft, such as bearings for antenna pointing systems, gyroscopes and inertia wheels, slip rings for electrical contacts, and transmission components.

While she was unable to comment on the timing of applications, Schadler said she is confident her team will have demonstrated several types of successful coatings by the time the project ends in 2009.

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