Tag: Penn State University

Boffins unveil sort of cloak of invisibility

invisibleScientists at Penn State university believe they have made considerable process in developing what they describe as a sort of cloak of invisibility. It’s not that, of course.

Postdoctoral fellow Zhi Hao said: “Previous attempts at cloaking using a single metasurface layer were restricted to very small sized objects. Also the act of cloaking would prevent an enclosed antenna or sensor from communicating with the otuside world.

So a group of scientists in the electrical engineering faculty at Penn say it’s developed a thin metamaterial coating that lets objects to function normally even though they don’t seem what they are.

The so called “illusing coatings” use a thin flexible substrate with copper patterns. When a device is probed by a radio frequency (RF) source, the scattered signature seems to be a dielectric material like silicon.

How does it work? The researchers take the object and surround it with either air or foam and then apply the ultrathin layer of dielectric with copper patterns designed for wavelengths they wish to cloak.

The practical benefits of the research could improve the way RF ID tags work or redistribute energy make things more rather than less visible.

Diamond nanothreads could lift us to space

Diamond nanothreads, PennA team of researchers at Penn State University said it has produced ultrathin diamond nanothreads that could just possibly lead to the production of a space elevator between earth and the moon.

John V Badding, a professor of chemistry at Penn, said: “One of our wildest dreams for the nanomaterials we are developing is that they could be used to make the super-strong, lightweight cables that would make possible the construction of a “space elevator”, which so far has existed only as a science-fiction idea.”

The discovery shows that the nanothreads include a long strand of carbon atomswhich resemble the fundamental unit of a diamond.

Badding said: “It is as if an incredible jeweller has strung together the smallest possible diamonds into a long miniature necklace. Because this thread is diamond at heart, we expect it will prove to be extraordinarily stuff, extraordinarily strong, and extraordinarily useful.”

The threads are extremely small and only a few atoms across.

Apart from the wild dream of producing an elevator between earth and the moon, more practical applications include materials in vehicles that are lighter, more fuel efficient and so less polluting.

One obstacle is that high pressure needed to produce the diamond nanothreads limit production to only a few cubic millimetres at a time.