September 11, 2012
Smart Fabric Woven With Silver Thread Triggers Alarm When Disrupted
Brett Smith for redOrbit.com - Your Universe Online
German researchers have developed a new woven fabric with an embedded microcontroller that triggers an alarm when broken by potential thieves. The smart fabric can also locate the point of penetration and could be a cheap alternative to other anti-theft systems in certain situations.Erik Simon at the Fraunhofer Institute for Reliability and Microintegration IZM in Berlin managed the project that involves a fine lattice of conductive silver-coated threads. He said the material could be useful in guarding and monitoring the integrity of a large surface area.
"The fabric could be used to implement an entirely novel, invisible security system for buildings," Simon said, according to a Fraunhofer Institute statement. "This method has never been used before in this kind of application.”
To ensure that the textile could have commercial applications, researchers had to determine its reliability, durability, and its conductibility of electrical contacts. According to the statement, the alarm system withstood a series of harsh tests in the IZM laboratories. It was put through a 104 degree Fahrenheit wash, exposed to 1,000 hours of extreme-weathering conditions that included temperatures of 185 degrees Fahrenheit and 85 percent humidity. The fabric was then placed into a chamber where it was blasted with 1,000 temperature cycles ranging from minus 100 to plus 185 degrees Fahrenheit.
One of the benefits of the technology is its affordability. The production process uses standard materials and conductive threads that enable a signal-based communication system. According to Simon, another advantage is that “the conductive thread can be incorporated in the polyester substrate using an industry-standard textile-weaving process,” resulting in reams of fabric that can be customized to any length and size based on a desired functionality.
To incorporate the conductive lattice and the data-processing module that gives the fabric its function–a low-temperature process is used that borrows techniques such as adhesive pressure bonding and non-destructive welding from the semiconductor industry.
“This method has never been used before in this kind of application,” Simon said, adding that the process as “simple and reliable”.
According to the institute, the smart textile could be laid on the rafters of a roof or integrated into concrete walls as a discrete way to guard against break-ins. It could also be used to protect valuables being stored outside in shipping containers or pop-up vendors. The smart fabric´s ability to accurately identify a specific point of entry could be valuable in refining a specific security system if a break-in were to occur.
The IZM statement also suggested that the textile could have additional applications, including using it “as a backing material for floor coverings, in combination with pressure sensors that signal an alarm if an unauthorized person enters the room.”
Most importantly, the smart fabric appears to be a cost-effective alternative to contemporary security systems that are costly to install, maintain, and monitor.
For those with safety concerns surrounding an electrical fabric, the researchers say the current running through the threads is too weak to hurt humans or animals that inadvertently encounter it.