Invisibility Without Metamaterials
Researchers have found ways to make objects invisible using a crystal called calcite.
Research and development initiatives to achieve invisibility have all been focused on using metamaterials, or ‘artificially engineered materials with a negative refractive index that have already been used to render microscopic objects invisible in specific wavelengths of light.’ However, researchers from the Singapore-MIT Alliance for Research and Technology, the University of Birmingham, Imperial College, and the Technical University of Denmark have created a method of making things (or parts of them) invisible using a crystal called calcite.
‘‘This is a huge step forward as, for the first time, the cloaking area is rendered at a size that is big enough for the observer to ‘see’ the invisible object with the naked eye,” said Dr Shuang Zhang, lead investigator from the University of Birmingham’s School of Physics and Astronomy. “We believe that by using calcite, we can start to develop a cloak of significant size that will open avenues for future applications of cloaking devices.”