Invisibility
Researchers overcome size hurdle in quest for invisibility cloak
Efforts to create a working "invisibility cloak" have generally involved the use of artificial materials with a negative refractive index known as metamaterials. Another promising technique involves the use of a natural crystal called calcite that boasts an optical property known as birefringence, or double-refraction. While both methods have proven successful in rendering very small objects invisible in specific wavelengths of light by bending and channeling light around them, both techniques require the "cloak" to be orders of magnitude larger than the object being concealed. Researchers are now reporting progress in overcoming this size limitation using a technology known as a "carpet cloak." Read More
The quest to build a working “invisibility cloak” generally focuses on the use of metamaterials – artificially engineered materials with a negative refractive index that have already been used to render microscopic objects invisible in specific wavelengths of light. Now, using naturally occurring crystals rather than metamaterials, two research teams working independently have demonstrated technology that can cloak larger objects in the broad range of wavelengths visible to the human eye. Read More
Take some light bending metamaterials, incorporate them into flexible fabric and you have yourself an invisibility cloak. That's the theory anyway, and it doesn't stop at hiding objects. Building on the optical invisibility research of Professor Sir John Pendry, researchers from Imperial College, London, have now proposed that similar metamaterials could be used to conceal entire events – get ready for the "Spacetime cloak". Read More
Flexible metamaterials the key to a working invisibility cloak?
Scottish researchers are reporting a "practical breakthrough" that could lead to the development of that most sought after of wardrobe items – the invisibility cloak. The concept of the invisibility cloak (not pictured) is based around harnessing the unique electromagnetic wave-bending properties of metamaterials, but this poses problems when it comes to creating flexible surfaces suitable for applications like clothing and contact superlenses for visual prostheses... problems which the new material design known as "Metaflex" hopes to address. Read More
We’ve covered a few different research efforts looking to develop “invisibility cloak” technology on Gizmag, including 3D metamaterials that negatively refract visible and near-infrared light and U-shaped “nano-rings” that manipulate light. The latest news sure to get Harry Potter fans excited comes out of Michigan Technical University where Elena Semouchkina, an associate professor of electrical and computer engineering, has found ways to use magnetic resonance to capture rays of visible light and route them around objects, rendering them invisible to the human eye. Read More
A Harry Potter-style invisibility cloak is one more step closer to reality thanks to the work of a research team at the FOM Institute for Atomic and Molecular Physics (AMOLF) in the Netherlands, which has successfully harnessed the magnetic field of light to develop meta-materials that can deflect light in every possible direction. Read More
Over the last few years we’ve covered the development of “invisibility cloaks” using metamaterials – man-made structured composite materials exhibiting optical properties not found in nature that can guide light to achieve cloaking and other optical effects. In 2006, scientists at Duke University demonstrated in the laboratory that an object made of metamaterials can be partially invisible to particular wavelengths of light - not visible light, but rather microwaves. A few groups have even managed to achieve a microscopically-sized carpet-cloak. Now researchers have developed software that can show what such a cloaked object will actually look like. Read More
Harnessing the unique properties of metamaterials, researchers in China have recently published a work detailing the implementation of a thin air, broadband and remotely controllable 'invisible gateway' that is able to shield all types of electromagnetic waves while letting through all other physical objects. Read More
Mathematicians at the University of Utah have recently announced they have elaborated an innovative way to shield two-dimensional objects from all types of waves, from electromagnetic to those caused by natural events like earthquakes and tsunamis, leading the way to a completely new approach to achieving invisibility. Read More
Researchers at the Universitat Autonoma de Barcelona have recently designed a peculiar material — called a dc metamaterial — that has the property of making objects wrapped in it undetectable to magnetic and very low-frequency electromagnetic fields. The breakthrough brings the dream of "invisibility cloaking" closer to reality and could have important repercussions in both the military and medical fields. Read More
