Data Storage in Clothes!

Using magnetic properties of conductive thread, University of Washington researchers are able to store data in the fabric. Here, the code to unlock a door is stored in fabric patch and ready by an array of magnetometers.

A new type of smart fabric developed at the University of Washington could pave the way for jackets that store invisible passcodes and open the door to your apartment or office.The UW computer scientists have created fabrics and fashion accessories that can store data — from security codes to identification tags — without needing any onboard electronics or sensors.

“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 the 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.”

Most people today combine conductive thread — embroidery thread that can carry an electrical current — with other types of electronics to create outfits, stuffed animals or accessories that light up or communicate.

But the UW researchers realized that this off-the-shelf conductive thread also has magnetic properties that can be manipulated to store either digital data or visual information like letters or numbers. This data can be read by a magnetometer, an inexpensive instrument that measures the direction and strength of magnetic fields and is embedded in most smartphones.

Like hotel card keys, the strength of the magnetic signal weakens by about 30 percent over the course of a week, though the fabric can be re-magnetized and re-programmed multiple times. In other stress tests, the fabric patch retained its data even after machine washing, drying and ironing at temperatures of up to 320 degrees Fahrenheit.

The researchers enabled gesture recognition by sewing
 the magnetized thread into the fingers of the glove.

The team also demonstrated that the magnetized fabric could be used to interact with a smartphone while it is in one’s pocket. Researchers developed a glove with conductive fabric sewn into its fingertips, which was used to gesture at the smartphone. Each gesture yields a different magnetic signal that can invoke specific actions like pausing or playing music.In the team’s tests, the phone was able to recognize six gestures — left flick, right flick, upward swipe, downward swipe, click and back click — with 90 percent accuracy.
Future work is focused on developing custom textiles that generate stronger magnetic fields and are capable of storing a higher density of data.