10th July 2013 San Francisco, USA

Invisibility Cloaks: No Longer Exclusive to the Wizarding World

I know what you’re thinking – this is a blog for the Science and Innovation Network. What’s next, a post on fire-breathing dragons? But in fact, over the course of the past decade the concept of invisibility cloaks has turned from fiction to science. Much to the dismay of Harry Potter fans across the globe, however, the aim of this research is not to create a literal cloak of invisibility. In fact, Sir John Pendry, the British physicist at Imperial College London responsible for this concept, explains that the outcome of his research, “is going to be very far from what most people would think of as a cloak: something thin and flexible, which you can wrap around yourself and change its shape.”

Pendry has recently been awarded the UK Institute of Physics (IoP) distinguished Newton Medal “for his seminal contributions to surface science, disordered systems and photonics.” The Newton Medal, the highest honour of the UK’s IoP, is annually awarded to a physicist in any subject area for his or her outstanding contributions to the field. John Pendry has made significant and influential contributions to the theory of surfaces and of low energy electron diffraction, but the IoP said that it was the British physicist’s work on the “cloak of invisibility” that has piqued the interest and imagination of people across the world.

Pendry’s invisibility cloak is a transformational optical device that can be used to conceal objects from detection from light waves by transforming the space occupied by the object making it “invisible.” The key to this device is the use of a new class of materials known as ‘metamaterials’ first introduced by Pendry in 2006. These artificial materials are precisely engineered from metals or plastics to have structures that manipulate sound, vibration, or light waves. They’re also tiny – smaller than a wavelength of light. The cloak works by using these ‘metamaterials’ to control and manipulate the electromagnetic spectrum (light waves) by redirecting the waves around an object rendering it virtually invisible – much like a rock diverting water in a stream. The scientist himself describes this idea in its simplest terms by explaining that “you just want to grab hold of the light coming from an object, guide light around the hidden thing, and then return it to the path it was going on originally.” Now, why didn’t I think of that?

This new field of research has rapidly expanded and been applied in other areas of science such as the manipulation of sound waves to create ‘acoustic cloaks’ and cloaking buildings from earthquakes by redirecting seismic waves around structures. Scientists have also began looking into cloaking heat which involves the transformation of space so that heat flows around an object as it would normally would through the object. This would make the object undetectable to heat sensors therefore rendering it invisible. This type of cloaking might have a practical use in the form of miniaturized devices used to cool computer chips.

Needless to say, like most areas of science, the potential outcomes of this research are diverse and vast. One thing that we know for sure is that this highly sought after prize is in the hands of a worthy British scientist who had the curiosity, expertise and creativity to introduce this concept to the world.

And as for that post on fire-breathing dragons, you’ll just have to stay tuned.

About Emily Keir

Emily joined the San Francisco S&I team in May 2012 after graduating from the University of California, Los Angeles with an honours degree in Environmental Studies/Geography and Environmental Systems and…

Emily joined the San Francisco S&I team in May 2012 after graduating from the University of California, Los Angeles with an honours degree in Environmental Studies/Geography and Environmental Systems and Society. While working towards her degree at UCLA, she conducted primary remote sensing research and spent time abroad studying ecology, economics, and biology at Cambridge University. She started her work with the British Consulate as an intern for the Science and Innovation team in Los Angeles before becoming an officer in San Francisco.

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