Always worn silk with golden embroidery to stand out in a crowd? Well, now you can wear the shimmering garment to become invisible in a crowd, just like Harry Potter in the wizard films.
For the first time ever, scientists have created an invisibility cloak made from silk, and coated in gold.
The new metamaterial, as invisibility cloaks and their kin are technically called, only works on relatively long terahertz waves (a region of the electromagnetic spectrum between radio and infrared light).
But the Boston-area scientists who developed the technology think that silk could work as an invisibility cloak at much smaller wavelengths, even in the visible range.
The research could lead to a wide range of optically unique materials for use in biomedicine or defence.
"This is an unusual angle for a metamaterial because of silk's ability to interface with the human body," something that no other metamaterial is currently capable of, Discovery News quoted Fiorenzo Omenetto, a scientist at Tufts University who, along with colleagues at Boston University, helped develop the silk-based metamaterial.
"On the sensing side it gives you a platform that is very adaptable," he added.
To create their silk-based metamaterial, the scientists, including Richard Averitt, started with a one-centimeter-square piece of silkworm silk.
Onto that tiny piece of dielectric silk they stenciled 10,000 gold resonators.
Ordinarily when silk is exposed to terahertz waves they pass straight through it.
When the new silk metamaterial was subjected to T-rays the scientists detected a resonance.
A metamaterial that works in the terahertz range is nothing new. But, unlike other metamaterials, silk is biocompatable -- the human body won't reject silk-based implants the way it does with most other materials.
The scientists implanted the patterned silk into a muscle, and still detected a resonance.
The potential applications of silk-based invisibility are huge.
Tufts scientists are not even focused on Harry Potter or Star Trek-style invisibility materials, although they say that is one potential application.
One of the first biomedical uses could be as an implantable glucose sensor for diabetics. As the level of glucose changes inside the body, it changes the silk. Then as the silk changes, so does the metamaterial printed on the silk.
The change would then be relayed to the person's cell phone- no needle prick necessary.
Silk-based invisibility would also allow doctors and radiologists to cloak various organs or tissues and see through them, said Omenetto, getting a better image of the organs or tissues usually hidden behind.
The study has been published in the journal Advanced Materials.