Shape shifters: Researchers create new breed of antennas
(PhysOrg.com) -- Antennas aren't
just for listening to the radio anymore. They're used in everything from cell
phones to GPS devices. Research from North Carolina State University is
revolutionizing the field of antenna design - creating shape-shifting antennas
that open the door to a host of new uses in fields ranging from public safety
to military deployment.
The antennas consist of liquid metal
injected into elastomeric microchannels.
The antennas can be deformed (twisted
and bent) since the mechanical properties
are dictated by the elastomer and not
the metal.
Credit: Ju-Hee So, North Carolina State University
Modern antennas are made from copper
or other metals, but there are limitations to how far they can be bent - and
how often - before they break completely. NC State scientists have created
antennas using an alloy that "can be bent, stretched, cut and twisted -
and will return to its original shape," says Dr. Michael Dickey, assistant
professor of chemical and biomolecular engineering at NC State and co-author of
the research.
Elongating the wires by stretching
changes the resonant frequency and is
therefore a wireless sensor of mechanical
deformation.
Credit: Ju-Hee So, North Carolina State University
"Because the alloy remains a
liquid," Dickey says, "it takes on the mechanical properties of the
material encasing it." For example, the researchers injected the alloy
into elastic silicone channels, creating wirelike antennas that are incredibly
resilient and that can be manipulated into a variety of shapes. "This
flexibility is particularly attractive for antennas because the frequency of an
antenna is determined by its shape," says Dickey. "So you can tune
these antennas by stretching them."
While the alloy makes an effective
antenna that could be used in a variety of existing electronic devices, its
durability and flexibility also open the door to a host of new applications.
For example, an antenna in a flexible silicone shell could be used to monitor
civil construction, such as bridges. As the bridge expands and contracts, it
would stretch the antenna - changing the frequency of the antenna, and
providing civil engineers information wirelessly about the condition of the
bridge.
Flexibility and durability are also
ideal characteristics for military equipment, since the antenna could be folded or
rolled up into a small package for deployment and then unfolded again without
any impact on its function. Dickey thinks these new applications are the most
likely uses for the new antennas, since the alloy is more expensive than the
copper typically used in most consumer electronics that contain antennas.
Source: http://www.physorg.com/news178897908.html