Exeter physicist bends light waves on surfboards

A University of Exeter scientist is bringing together his passions for physics and surfing with research that could inspire a host of new technologies. Dr Matt Lockyear is using foam from inside surfboards to make materials that can manipulate light.

Scientists across the globe are trying to develop materials that can refract light to create 'invisibility cloaks', which are of particular interest to the aerospace industry. 'Invisibility cloaking' means building properties into a material that allow the device to guide light waves around an object, making it invisible.

Dr Matt Lockyear grew up in Exeter and completed his undergraduate Physics degree at the University of Exeter as a mature student. He returned for his PhD after working as an engineering manager at BNFL Sellafield, and now works as a Research Fellow in the Electromagnetic and Acoustic Materials Group in Physics. His 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. Luckily, his friend Tris Cokes owns the Redruth-based surfboard blank manufacturing company Homeblown. Tris was able to provide him with samples of the material, and then lent him the factory to test the loading of the foams with high refractive index powders.

Dr 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. Dr 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.