Science Fiction
Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 |
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 ")
US Army IBEX Exoskeleton Walks Troops Out Of Danger
'The suit stands up and starts walking, gripping me round the calves and waist, taking the bulk of my weight off my throbbing feet.' - Iain Banks, 1987.
Terraformer Industries Make Methane
'Drake was the young spatial engineer he employed to terraform the little rock...' - Jack Williamson, 1942.
Ridiculous 'Ghost Murmur' Tech Still Science Fiction
'...it rears and spreads its fan. It can pick one man out of a crowd.' - Roger Zelazny, 1967.
Infrared Contact Lenses To See In The Dark
'I can see in the dark, Case.' William Gibson, 1984.
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.
Science Fiction
Timeline
1600-1899
1900-1939
1940's 1950's
1960's 1970's
1980's 1990's
2000's 2010's
Current News
AI Operates An Excavator
'So far as I could see, the thing was without a directing Martian at all.'
US Army IBEX Exoskeleton Walks Troops Out Of Danger
'The suit stands up and starts walking, gripping me round the calves and waist, taking the bulk of my weight off my throbbing feet.'
Boy Makes Biomimetic Turtle Robot
't came out into plain view. Darkington glimpsed a slim body and six short legs of articulated dull metal.'
Elon Musk Wants Data Centers In Space
'Internally its made up of millions of components, but the most important ones are the thinking and memory parts of the Mind proper.'
Origin F1 Humanoid Robot's Facial Skin
'I could look down at that face of carefully molded synthetic rubber, tinted the exact shade of the doctor's living flesh.'
Grok And The City Fathers From 'Cities In Flight' By James Blish
'Chris, the City Fathers are not interested in your welfare; I suppose you know that. They're interested in only one thing: the survival of the city.'
Why Not Move A Warehouse District?
'Did you never see a moving house before?'
Will An AI Found A New Religion?
'You must decide how you will worship Me.'
Terraformer Industries Make Methane
'Drake was the young spatial engineer he employed to terraform the little rock...'
I Need An Outdoor Spherical Display
'Usually a spherical display hovered in the centre...'
Worm Disrupts Physics Simulations Undetected For A Decade
'It diverts integers of the data, the fundamental message-units, so that they no longer agree.'
Muxcard Redditor's DIY Credit Card-Sized Computer
It's a computer, but just barely.
'Soft Assembly' Fashions That Fashion Themselves On The Wearer
'Clothes are no longer made from dead fibers of fixed color and texture that can approximate only crudely to the vagrant human figure...'
Orwell's Nightmare Of AI-Written Novels Comes To Pass
'Books were just a commodity that had to be produced, like jam or bootlaces.'
ISS Plagued By Leak - Again!
'There were perhaps a dozen bladder-like objects in the tunnel...'
Ridiculous 'Ghost Murmur' Tech Still Science Fiction
'...it rears and spreads its fan. It can pick one man out of a crowd.'
