Your shirt could be the only key you need – this smart fabric can function without any power source

Researchers from the University of Washington (UW) have devised a new kind of smart fabric that can store data, and – incredibly – does not need any electrical power to run it. The fabric can be used to store passcodes, keys, and other such information, but will not need a battery or other forms of power or sensors to operate it.

In a report by Science Daily (SD), it was noted that the team made use of only off-the-shelf conductive threads to create this fabric, simply exploiting the inherent magnetic properties of such threads that were previously undiscovered.

Data in the fabric can be read using existing hardware in smartphones, noted the report.

"This is a completely electronic-free design, which means you can iron the smart fabric or put it in the washer and dryer," said senior author Shyam Gollakota, associate professor in UW's Paul G. Allen School of Computer Science & Engineering. "You can think of the fabric as a hard disk – you're actually doing this data storage on the clothes you're wearing," he added.

The UW team were experimenting with conductive thread when they reportedly came across its magnetic properties. They were then able to manipulate it in such a way that it could store data – both digital and visual data, like letters and numbers.

One way to read the information off this smart fabric would be to use a magnetometer – instruments that measure the direction and strength of magnetic fields. Most smartphones have magnetometers in them and use it for navigation.

"We are using something that already exists on a smartphone and uses almost no power, so the cost of reading this type of data is negligible," said Gollakota.

In one of the experiments, the team reportedly sewed a small patch of the fabric to the cuff of a shirt and embedded it with a digital key to open a door. By waving it in front of the magnetometer-controlled lock, they were able to unlock the door.

The team was also able to write codes into ties, belts, necklaces and other articles of clothing, and later read them by simply swiping a smartphone across it.

They made use of regular sewing machines and made embroidered patterns on clothes using the conductive threads.

Data is written into the fabric by aligning the magnetic poles of the thread in specific directions. The directions that the poles point towards can be seen as the 1 and 0 that make up most digital data, noted the report. This can be done by physically rubbing a magnet against the thread.

Over the course of a week, the strength of the magnetic signals weaken by about 30%. However, they can be remagnetised and rewritten multiple times. The data was retained by the fabric even after passing it through a temperature of 320 degrees F, the scientists revealed.