Italian-led team moves closer to invisibility cloak
Italian-led team creates wave-bending silk
18 August, 16:23
(ANSA) - Rome - Science has moved a step closer to the creation of an invisibility cloak, according to a new study led by Italian physicist turned bioengineer, Fiorenzo Omenetto.
Omenetto's team at Tufts University near Boston has created a piece of material that could eventually be used to make whatever it covers invisible to the human eye. The design uses tiny structures smaller than electromagnetic waves, constructed in such a way as to divert waves around them, much like a rock diverts water in a stream.
The design currently only works with terahertz waves, which are much longer than light waves, but Omenetto believes exactly the same concept could eventually be used to divert light waves, the only electromagnetic waves visible to the human eye. The team started with a one-centimeter-square piece of silkworm silk, onto which 10,000 gold resonators were stenciled.
Normally terahertz waves pass straight through silk but this design produced a detectable resonance when exposed to the waves. Materials with the ability to divert electromagnetic waves, known as metamaterials, have been around for some time but the key element in this design lies with its component parts.
"The real novelty with this metamaterial is that it is completely biocompatible," explained Omenetto.
"This means it can be implanted directly into the human body without reactions".
The team inserted the material into the muscular tissue of a guinea pig and were still able to detect a resonance.
Although the invisibility cloak may some day become a reality, this discovery also has plenty of more immediate applications, starting with biomedicine.
"One example is the creation of a sensor for glucose in diabetics," explained Omenetto. The implanted silk would react to changes in the body's glucose level, which could be used to send a message to the person's mobile phone, for example.
"Another idea would be using it to make certain organs 'invisible', allowing radiologists to get a better view of parts that are normally hidden underneath," he said.
The study appeared in the latest edition of weekly journal Advanced Materials.
