INVISIBILITY

Most of us first came into contact with the notion of Invisibility Cloaks in the Harry Potter novel. While we do not have magic, technology today has come far enough that we have developed our own invisibility cloaks, or meta-material. Unlike Harry Potter where the cloak is an iridescent cloth that is draped over oneself and it immediately disappears from sight, today’s invisibility cloaks are much less advanced.

In order to recreate a Harry Potter-esque invisibility cloak, the material needs to not just hide the object, but also project the image of another object, usually the background. These stealth fabrics function by bending light rays around the object the cloak is supposed to hide, hence rendering the object ‘invisible’. In the past, Scientist had created materials that gave the illusion of light passing through a straight line in space, but these so-called “cloaks” only worked in terahertz frequencies between radio and infrared light, giving rise to the inventions of heating appliances such as microwaves.
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Today, scientists have made great progress in providing a semblance of invisibility, for example, UTD NanoTech Institute has created a  new 'invisbility cloak' inspired by the same natural phenomena responsible for desert mirages. The cloak is heated via electrical stimulation, and the sharp temperature gradient between the cloak and the surrounding area causes a steep temperature gradient that bends light away from the wearer. However, this 'cloak' has so far only been developed to fit in a petri dish, and the need for heat and water to cause invisibility still poses a large obstacle to bringing this technology further.

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Early this year in February 2013, Baile Zhang, an assistant professor of Physics at Nanyang Technological University in Singapore, demonstrated his "invisibility cloak" at the TED2013 talks in Long Beach. A significant breakthrough in the area of invisibility, his cloak is made of two optical crystals that are found in nature. When cemented together, they bend light and suppress shadows to the point that they can hide objects. The demo at the show saw the cloak (which is kept in a tiny clear box) make a Post-It note vanish.
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However, these amazing inventions, have only been developed to a small extent, and most of these materials are only nano-sized, some of the ‘cloaks’ only about the size of half a hair-width. With the rate that technology is advancing, there is great potential for invisibility to be extended to further use in various areas.

Future (Military).