It has been the stuff of science fiction and fantasy for generations - the ability to turn yourself or something you want to hide invisible. There's the Invisible Man, Harry Potter had an invisibility cloak, and Frodo's elven cloak in Lord of the Rings (while not an invisibility cloak) helped conceal him in tight situations.
In the modern day, we have stealth technology in the military along with researchers and scientists working with metamaterials, nanotechnology, and hobby-grade circuit boards to bring the dream of invisibility much closer to reality. One scientist postulates it could be as early as six months from now. Perhaps just in time for Christmas 2009?
An article has been published in Science magazine by Duke University professor, David Smith, highlighting his team's findings. To make something appear invisible, it starts with the metamaterial, a material where the surface at the microscopic level is smaller than the wave length of the light. To get this kind of surface, nanotechnology combines different materials in layers that each reflect light differently. The metamaterial changes the index of refraction to help bend the light around the object being hidden.
The reason this is a big deal is that until now, Smith's team had been able to make things appear invisible, but with longer microwaves. Now they are now able to make things appear invisible in infrared light.
Smith said: "The cloak would act like you've opened up a hole in space. All light or other electromagnetic waves are swept around the area, guided by the metamaterial to emerge on the other side as if they had passed through an empty volume of space."
In August 2008, another group of researchers led by Xiang Zhang reported that they could bend visible light in three dimensions. Using multiple layers of silver and magnesium fluoride, they have created a metamaterial that is transparent over a wide range of wave lengths.
There are several potential military applications, but the research team also sees commercial uses - like coating a factory or building that blocks a view of distant scenery or using the metamaterials to help focus light to create a more perfect lens. Of course the application lots of people are looking for is personal - their own invisibility cloak - even if the cloak would make you appear more like the Predator than the Invisible Man.
Smith thinks metamaterial that works in visible light could be commercially viable in six months - the circuit boards used in his project were hobby-grade and cost about $1 to assist with covering the 50cm by 10cm demonstration platform.
Some enterprising toy maker is no doubt drooling over the possibility of getting this out just in time for the Christmas 2009 shopping season. Let's hope ... and if you're that toy-maker, send me a note.