Engineers embroider antennas onto clothes

Posted by Kate Taylor

Ohio State University engineers are getting pretty handy with a sewing machine, working on ways to incorporate radio antennas directly into clothing using plastic film and metallic thread.

They've developed a new antenna design with a range four times larger than that of a conventional body-worn antenna like those used by American soldiers today.

"Our primary goal is to improve communications reliability and the mobility of the soldiers," says research associate professor of electrical and computer engineering Chi-Chih Chen.

"But the same technology could work for police officers, fire fighters, astronauts – anybody who needs to keep their hands free for important work."

The system takes elements from previous wearable antennas and combines them in a new way, adding a new computer control device that lets multiple antennas work together in a single piece of clothing.

The result is a communications system that can send and receive signals in all directions, even through walls and inside a building, without the wearer needing to carry an external antenna.

The integrated computer control device senses body movement and switches between the antennas to activate the one with the best performance given the body's position.

The engineers created a prototype antenna by etching thin layers of brass on a commercially available plastic film, called FR-4, which is light and flexible, and can be sewn onto fabric.

They attached it into a vest at the chest, back, and both shoulders. The computer controller, a metal box a little smaller than a credit card and an inch thick, was worn on a belt.

In laboratory tests, the experimental antenna system provided significantly greater signal strength than a conventional military 'whip' antenna, giving a range four times greater, and worked in all directions.

They team's now partnering with an antenna design company, Applied EM of Hampton, VA, to commercialize the research. They reckon their prototype would cost $200 per person, but that mass production would bring the cost significantly down.

In the meantime, they're working on printing antennas directly onto clothing, and even embroidering them with metallic threads. A home sewing machine is now part of their laboratory equipment.

As a result, the technology could be used for the elderly or disabled to allow them to communicate in an emergency, without the possible stigma of a more visible assistive device.