Making planes invisible
New surface coatings produced by the manipulation of particles and separate atoms could have highly unusual features, such as making aircraft invisible to radar, according to Dr Dmitri Gramotnev, co-leader of Queensland University of Technology’s Applied Optics program.
Dr Gramotnev (pictured) said the research his team is undertaking could lead to a breakthrough in nano-fabrication, resulting in the design of new surface coatings with predetermined properties.
The process uses Brownian forces – the term used to describe the random movement of small particles – which change their nature when subject to strong temperature variations.
“Moving from hot to cold regions results in a controlled and very strong redistribution of particles or molecules on surfaces,” Dr Gramotnev said.
“We’ve found that the trapping efficiency of thermal tweezers, as the process is called, increases as the size of particles decreases, contrary to traditional optical tweezers whose efficiency decreases with decreasing particle size.
“As a result, thermal tweezers can be used to manipulate particles that are just a few nanometres (one-billionth of a metre) in diameter.”
Applications include nanofabrication processes where surface structures, chips and other devices could be made using laser radiation.
“We’re looking at nano-particles as a new tool for nano-fabrication and advanced materials.
“Coatings could also be created for screening equipment that detects specific materials such as explosives,” Dr Gramotnev said.
Website: http://www.sci.qut.edu.au/research/programs/optics/
Last reviewed 5 September 2007
