Shape-Changing Metal Antenna

Researchers at Utah and North Carolina have created a controllable metal antenna that can change its shape, and thus the frequency at which it resonates, on demand.


(Shape-Changing Metal Antenna)

To fabricate the antenna, the researchers injected a conductive, low-viscosity metal alloy (eutectic gallium indium, or EGaIn) into a 51-mm-long microchannel that is divided into four segments. Two rows of posts placed perpendicular to the channel divide the inner and outer segments of the antenna. A thin, membrane-like solid oxide skin spontaneously forms on the metal surface that mechanically stabilizes the metal at the posts, preventing metal in adjacent segments from merging. The liquid metal remains stable as long as its surface oxide is not ruptured.

At a length of 25 mm, the initial dipole antenna state, defined by the two inner segments, represents the shortest of three possible states. As the shortest antenna, it also has the highest frequency. In order to elongate the antenna, and thus decrease its frequency, the researchers applied a critical pressure on the liquid metal at one segment boundary. This critical pressure ruptures the oxide skin and squirts the metal between the posts to merge with one of the outermost metal segments. This process increases the length of the antenna and creates a second state at a lower frequency than the first state. By controlling the spacing between the posts, the researchers could control the pressure at which the oxide ruptures.

To achieve the third state the one with the longest length and lowest frequency the researchers ruptured the skin on the other side of the antenna, allowing the liquid metal in the inner segment to merge with the other outer segment. Once the skin is ruptured, the metal flows extremely quickly in a few milliseconds due to its low viscosity and the short distance it has to travel.

In his 1942 novella Waldo, Heinlein draws on the idea of broadcast power. The aircars (including the amazing broomstick speedster) use standard, rigid antennas to draw power.

As the story progresses, the deKalb antennas mysteriously fail to function. When one of them is fixed by a "hex doctor", engineers go to investigate.

"What!" put in Stevens. "You don't mean to stand there and tell me an old witch doctor fixed your deKalbs."

"Not witch doctor - hex doctor..."

The skycar looked quite ordinary. Stevens examined the deKalbs and saw some faint chalk marks on their metal sides... "Watch while I cut in reception."

Stevens waited, heard the faint hum as the circuits became activized and looked.

The antennae of the deKalbs, each a rigid pencil or metal, were bending, flexing, writhing like a cluster of worms. They were reaching out, like fingers...
(Read more about Heinlein's broadcast power receptors)

From Physorg.

Scroll down for more stories in the same category. (Story submitted 7/31/2011)

Follow this kind of news @Technovelgy.

| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 0 )

Related News Stories - (" Engineering ")

Road Noise Charges Electric Cars With Peugeot Piezoelectric Billboard
''... major cities of Earth have free electrical power conveniently processed from their own noise.' - Lloyd Biggle, Jr. 1956.

California Gets Shockwave Rider-Style Avoidance Zones
'It was cheaper to pay the refugees to go without up-to-the-minute equipment.'

Helios Modular Touch Screen Wall Lights
'The walls and ceiling bore an irregular spacing of illuminum tiles...' - Richard Morgan, 2003.

Harvest Water From Air With Sunlight
'The atmosphere yielded its moisture with reluctance.' - George Lucas, 1976.

 

Google
  Web TechNovelgy.com   

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

 

Current News

Road Noise Charges Electric Cars With Peugeot Piezoelectric Billboard
''... major cities of Earth have free electrical power conveniently processed from their own noise.'

Unsinkable Metal Latest Gates Obsession
'A metal... light as cork.'

M-Blocks 2.0 Self-Assembling Robots
'Faster the cubes moved...'

NASA 'Broomstick' Recalls SciFi Ideas
'The appearance was enough like a giant witch's broom to justify the nickname.'

Orbital Display's Low Earth Orbit Advertisements
'A vast circle of scarlet stars came up into the greenish desert dusk.'

Neuromorphic Computing Hardare
'He had constructed an organ, a brain, of metal, entirely inorganic and lifeless...'

Vascularized Human Skin 3D Printed
Hey Fishboy!

Trillionaires Still Earth-Bound
'I shall never forget the sight... when the yellow gleam of the precious metal appeared under the star dust.'

Digit V2 Bipedal Robot From Agility Robotics
Oh, and now I suppose someone will develop the robotic porch pirate.

3D Printed Dubai Building Is World's Largest
'This thing will start at one end of ...a house and build it complete to the other end, following drawings only.'

Grow Plants On Moon Or Mars!
'In contrast to the airless desolation outside, the interior of this five-acre greenhouse was the one most desirable place to be.'

California Gets Shockwave Rider-Style Avoidance Zones
'It was cheaper to pay the refugees to go without up-to-the-minute equipment.'

Microbot Interstellar von Neumann Explorers
'Evidently they have never had a planet of their own...'

Hail SmartCan! Your Trash Bin Takes Itself Out
'...a waste can twenty feet away stirred into life.'

Finally! Microsoft Surface Neo And Surface Duo Implement Excellent Courier Idea
'Runcible, whose pages were thicker and more densely packed with computational machinery...'

Tap Strap 2 Now With Air Mouse
'He waved his hand and the circuit switched abruptly.'

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.