The quest for a Harry Potter-style invisibility cloak has taken another step big step forward, as engineers from the UK have for the first time successfully demonstrated a device which enables curved surfaces to appear flat when exposed to electromagnetic waves.
While their breakthrough doesn’t mean that people or objects are going to be able to disappear from sight anytime soon, it could change how antennas are tethered to their platform, making it possible for different sized and shaped ones to be attached to a variety of unusual surfaces.
According to study co-author Yang Hao, a Professor of Antennas and Electromagnetics in the School of Electronic Engineering and Computer Science at Queen Mary, University of London (QUML), his team’s design was “based upon transformation optics,” which is one of the primary concepts driving the ongoing research into the invisibility cloak concept.
“Previous research has shown this technique working at one frequency,” Professor Hao added in a statement Friday. “However, we can demonstrate that it works at a greater range of frequencies making it more useful for other engineering applications, such as… the aerospace industry.”
Breakthrough could benefit a number of different industries
The QMUL engineers coated a curved surface, approximately the same size as a tennis ball with a nanocomposite medium, with seven distinct layers called graded index nanocomposite. Each of the layer had a different electrical property based on its position, enabling an object to be hidden or “cloaked” rather than causing electromagnetic waves to be scattered.
When the cloaking device is not in use, the object’s presence along the path of the traveling wave causes a drastic change in its electric field configuration, Hao and his colleagues explained. Once activated, however, the application of the graded-index nanocomposite causes a reduction in how much shadowing is visible immediately after the object, as well as noticeable improvement in the reconstruction of wave fronts.
“In this paper, we experimentally demonstrate for the first time a dielectric surface wave cloak from engineered gradient index materials to illustrate the possibility of using nanocomposites to control surface wave propagation through advanced additive manufacturing,” they wrote, adding that the design “has much wider applications” than similar devices, “which span from microwave to optics for the control of surface plasmon polaritons (SPPs) and radiation of nanoantennas.”
“We demonstrated a practical possibility to use nanocomposites to control surface wave propagation through advanced additive manufacturing,” added lead author Dr. Luigi La Spada, also of QMUL. “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.”
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Image credit: Dr La Spada
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