Experimental antenna-clothing outperforms regular antennas
By Ben Coxworth
August 24, 2011
In the recent past, we've seen outfits that incorporate bio-sensors and batteries, and even a bikini with integrated solar cells. One of the latest innovations in smart fabrics, however, allows a person's clothing to act as multiple antennas. Developed at Ohio State University (OSU), the system could prove particularly useful to soldiers, who don't want to be encumbered by a protruding whip antenna.
While this is not the first time that clothing has been used to send and receive radio signals, the OSU technology is unique in that it uses a computer control device to facilitate several antennas within one piece of fabric.
The engineers have created a prototype, made by etching thin layers of brass onto commercially-available FR-4 flexible plastic film, then sewing that film onto conventional fabric. Four patches of the plastic were attached to a vest on the chest, back and both shoulders. These were wired to the controller, an inch-thick metal box slightly smaller than a credit card, which was worn on a belt.
Because the body's position may result in one or more of the antennas being blocked by obstacles, or short-circuited against the wearer's skin, the controller is able to switch between antennas so that the one best able to transmit and receive is activated. In lab tests, the vest was found to be able to work in all directions, offering four times the range of a standard military whip antenna.
The OSU team is now looking into printing such antennas directly onto clothing, or embroidering them into it using metallic thread. They have partnered with tech company Applied EM, to commercialize the technology. It is estimated that the systems might initially cost about US$200 each, but prices should drop as production increases.
Along with the military applications, it has also been suggested that the antennas could be used in clothing for the elderly or disabled, which would allow them to communicate in emergencies without having to wear conspicuous assistive devices.
The research was recently published in the journal IEEE Antennas and Wireless Propagation Letters.