Exeter, UK -- Dr Matt Lockyear of the University of Exeter, UK, is using polyurethane foam from inside surfboards to make materials that can manipulate light, creating an "invisibility cloak."
Lockyear's research focuses on metamaterials: materials that consist of specifically engineered 'pseudo-atoms' to provide bulk material or interface properties that are not found in nature. For his work, Dr Lockyear needed to find a material that is uniformly dense, and in response to electromagnetic radiation, behaves in a similar way to air. He discovered that the foam inside his surfboards was ideal for his experiments, according to a 27 July news release from the University of Exeter.
The Phd student collaborated with his friend Tris Cokes, owner of UK-based surfboard blank manufacturing company Homeblown, which uses only MDI-blown (methylene diphenyl diisocyanate) foam in its boards. Cokes provided samples of the material, and then lent Lockyear the factory to test the loading of the foams with high refractive index powders.
Lockyear has recently built what he describes as a 'surface wave black hole' using the surfboard foam. He has created a circle of material that has a radially graded index (the higher the index, the slower the light travels through the medium), and placed it on the surface of a metamaterial. The radiation propagating across the metamaterial is then refracted, spiralling inwards to an absorbing core.
Lockyear is now working on the surface wave invisibility cloak as a stepping stone to his current research project's ultimate goal, a free space 3D invisibility cloak.
"I never thought I'd be able to combine my passion for physics with my love of surfing - usually one competes with the other. But the foam inside the boards I've been riding for all these years has proved absolutely perfect for my research," Lockyear said.
"I was having a discussion with a colleague regarding suitable materials for the project whilst looking at one of Tris's foam blanks propped up against the office wall, which I had been meaning to turn into a 6ft 10 single fin pintail. I am also very lucky to have an office opposite the theory guys who, quite literally, wrote the book on transformation optics," he added.