Electrical engineers from the University of California have created a new ultra-thin metamaterial that could provide a cloaking device and make UAVs (Unmanned Aerial Vehicles) invisible. The new material creates invisibility and leaves no electronic, infrared or visual signatures for enemies to detect.
The new design uses “an ultra-thin Teflon substrate, studded with cylinders of ceramic, that can ‘bend’ light waves around objects coated with it, creating a cloak. The Teflon has a low refractive index, while the ceramic’s refractive index is higher, a combination which allows light to be dispersed through the sheet without any absorption,” according to researchers.
“Invisibility may seem like magic at first, but its underlying concepts are familiar to everyone. All it requires is a clever manipulation of our perception. Full invisibility still seems beyond reach today, but it might become a reality in the near future thanks to recent progress in cloaking devices,” Boubacar Kanté, a professor at the University of California, added.
“Up to now, the main theoretical tool used for designing invisibility cloaks has been transformation optics / conformal mapping – according to Fermat’s principle, an electromagnetic wave will travel between two points along the path of least time. In a homogeneous material, this path is just a straight line. However, in an inhomogeneous material, the path becomes a curve because waves travel at different speeds at different points. Thus, one can control the path of waves by appropriately designing the material parameters (electric permittivity and magnetic permeability),”according to Defense Update.
“By scattering the electromagnetic radiation – in the visible, infrared or radar spectrum, such metamaterial will be able to render a coated object undetectable in these wave frequencies, by forcing light or radar waves to bypass the object surface through the coating, which effectively “cloaks” the object.”
Previous projects that focused on producing cloaking technology required many layers of material to cover an object, thus resulting in very thick layers. The new metamaterial is extremely thin and is better capable of hiding three dimensional objects. The cloak produced also won’t reduce intensity when light is reflected from the coating, which allows the object to remain invisible.
This discovery is ideal for the military and defense industries. It would give the military vital stealth advantages and provide additional security in warzones and battlefields. “Creating the effect of an invisibility cloak offers a real-world solution to concealment, which can provide the military with air superiority. While this cloak has numerous applications for the military, this technology will create a ripple effect beyond the battlefield that will improve the performance of other diverse applications,” the researchers added.
This technology may also increase the signal speed of optical communication and increase the ability to collect solar energy.
“Doing whatever we want with light waves is really exciting. Using this technology, we can do more than make things invisible. We can change the way light waves are being reflected at will and ultimately focus a large area of sunlight onto a solar power tower, like what a solar concentrator does. We also expect this technology to have applications in optics, interior design and art,” Kanté said.
