Purdue University in Indiana in the US has just developed a new lightweight metamaterial composite that combines nanolayers of aluminium oxide with graphene… meaning its strength to weight ratio is very high and the density is low, with potential applications from aerospace to buildings.
The material itself has a honeycomb microstructure, so even though both ceramic and graphene are brittle it is structurally robust and is super-elastic. It also boasts thermal insulation, electrical conductivity and high strength, so there are all sorts of different applications the metamaterial could be used for.
Typically, graphene would degrade at high temperatures but the ceramic affords the metamaterial with high heat tolerance and flame resistance – so it could be used, for example, as a heat shield for aircraft.
Or it could be used as a substrate material in flexible electronic gadgets thanks to its lightweight nature, and its high strength and shock-absorbing properties. What’s more, the process of creating the composite material could potentially be scaled up for industrial manufacturing as well.
Gary Cheng, associate professor at the School of Industrial Engineering, said: “The outstanding properties of today’s ceramic-based components have been used to enable many multifunctional applications, including thermal protective skins, intelligent sensors, electromagnetic wave absorption and anticorrosion coatings … This metamaterial demonstrates a sequence of multifunctional properties simultaneously that have not been reported for ceramics and ceramics–matrix–composite structures.”
Future work is set to be carried out to improve the properties of the material, perhaps by controlling the microstructure to tune material properties, scaling the process for manufacturing and by changing its crystalline structure.
Similar work into super-materials was recently carried out by the University of Bristol and the University of Sussex as well, with a new finely engineered surface developed that bends, shapes and focuses sound waves as they pass through it.
Sound fields are routinely used in medical imaging and therapy, as well as consumer products like ultrasonic haptics and audio spotlights. But this recent development could soon be used as a simpler and cheaper way of creating shaped sound waves through the use of acoustic metamaterials.
The metamaterial layers could be used in all sorts of different applications, such as directing or focusing sound on a particular location. Smaller versions, meanwhile, could be used to destroy tumours in the body by focusing high intensity ultrasounds.
Dr Gianluca Memoli from the University of Sussex explained that these metamaterial bricks can actually be 3D printed and then put together to create any kind of sound field imaginable… something along the lines of a DIY acoustics kit!
The teams are now apparently working on making the metamaterial layers more dynamically reconfigurable, which would mean cheap imaging systems could be made either for crack detection or medical diagnostics.
Those of you interested in finding out more about precision engineering and more should get in touch with the Pentag Gears team today.