Would you like to become invisible to bystanders like Harry Potter uses to do? Soon it might be possible thanks to the work done by a team of researchers from the Department of Biomedical Engineering at Tufts University, Medford (Massachusetts) and the Department of Physics and Mechanical Engineering of the university in Boston under the direction of the Italian scientist Fiorenzo Omenetto.
The prototype developed by the group of dr. Omenetto was obtained by applying metamaterials (already mentioned in this previous post: Engineered metamaterials expand views on electromagnetism) which are artificially synthesized materials possessing electromagnetic properties not found in nature. These metamaterials can act as antennas and in particular frequency range they can curve radiation paths. This means that a straight ray of light could be curved around your body and emerge from it as if your body was not on its path.
In order to obtain this invisibility cloak researchers sprayed gold-based metamaterial structures directly on pre-made silk films with micro-fabricated stencils using a shadow mask evaporation technique. Spraying the metamaterial onto the flexible silk films created a composite so pliable that it could be wrapped into small, capsule-like cylinders. Each fabricated sample was 1 square centimeter and contained 10,000 of those cylinders. Each of them is a small resonator with a very particular behaviour.
As those resonators presently only work at Thz frequencies and not in the visible spectrum, the invisibility cloak is yet to come, but we already have other viable usages for them.
These resonators could be used to manufacture components for implantable electromagnetic contrast agents or for bio-monitoring applications.
For example, imagine an an tenna for glucose sensors made of metamaterials printed on silk. This sensors, implanted in diabetics, could monitor glucose levels and by having an antenna could signal this real-time piece of information to an external receiver like the patient’s cell phone. Being printed on silk this particular antenna would have very low rates of rejection.
Being able to instrument implants with antennas opens other new scenarios. Imagine the benefits of being able to control release rates of cardiac drugs from an internally implanted supplier.
At the time of this writing there’s of a series of in vitro experiments ongoing but very soon we could see real products of this type.
It may seem curious that silk (albeit in a modified form) the material of the future, is already thousands of years old!
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