Screening material may enable non invasive sensing devices
1 min read
US researchers have developed a cloaking material that, despite being just a few microns thick, can hide 3d objects from microwaves. The team from the University of Texas at Austin calls the layer a 'metascreen'.
Microwave invisibility has been created using a 'fishnet' of 66µm thick strips of copper tape attached to a 100µm thick flexible polycarbonate film. In tests, the material was used to cloak an 18cm cylindrical rod from microwaves and showed its best performance with 3.6GHz microwaves over a moderately broad bandwidth.
While the immediate application of the technology is with microwaves, the researchers believe it will have wider use. "We have envisioned other exciting applications using the mantle cloak and visible light, such as optical nanotags and nanoswitches and non-invasive sensing devices, which may provide several benefits for biomedical and optical instrumentation," said Professor Andrea Alu.
Previous attempts at cloaking have used metamaterials to bend waves around an object. However, in this approach, which the researchers call 'mantle cloaking', the metascreen cancels out the waves as they are scattered off the cloaked object.
The researchers will now be looking at the use of mantle cloaking to hide an object from visible light. "Metascreens are easier to realise at visible frequencies than bulk metamaterials," Prof Alu continued. "However, the size of the objects that can be efficiently cloaked with this method scales with wavelength."
