Scientists at Queen Mary University of London (QMUL) have developed a new material using a composite material with nano-size particles that has been able to make test objects “disappear.” For the first time, researchers demonstrated a practical cloaking device that has the ability to make curved objects seem flat to electromagnetic waves. The material makes use of somehow “manipulating” radio waves for it not to appear to monitors. The researchers coated a curved surface with a nanocomposite medium, which has seven distinct layers (called graded index nanocomposite) with electric properties. The electric property of each layer varies depending on its position, and the effect hides an object that would have caused surface waves to be scattered. The experiment was carried out by coating a cosine-curved metal plate with the material and observing it from a monitor. The original design approach has much wider applications, ranging from microwave to optics for the control of any kind of electromagnetic surface waves. Co-author Yang Hao said: “The design is based upon transformation optics, a concept behind the idea of the invisibility cloak. Previous research has shown this technique working at one frequency. However, we can demonstrate that it works at a greater range of frequencies making it more useful for other engineering applications, such as nano-antennas and the aerospace industry.” First author Luigi La Spada said: “The study and manipulation of surface waves is the key to develop technological and industrial solutions in the design of real-life platforms, for different application fields. Spada added, “We demonstrated a practical possibility to use nanocomposites to control surface wave propagation through advanced additive manufacturing. Perhaps most importantly, the approach used can be applied to other physical phenomena that are described by wave equations, such as acoustics. For this reason, we believe that this work has a great industrial impact.” The results of the findings were published in Scientific Reports on Friday.
