Interview with Justin Chan & Shyam Gollakota

In the past, our lab has worked on projects that involved conductive thread and magnetometers (sensors that can detect a magnetic field) on smartphones. We wondered if we could magnetise the conductive thread, similarly to how one can magnetise a metal nail. To do this, we took a permanent fridge magnet and rubbed it across the conductive thread. When we brought it close to the smartphone, it was able to sense whether the thread was close by. We then realised that with this capability we could create clothes that can store data and act like a magnetic hard disk.

Despite this initial decrease, our fabrics do not get completely demagnetised. In fact, our conductive fabrics still retained a magnetic field even after several months. Our approach is similar to hotel keycards which also have to be remagnetised regularly. Thus, our fabrics are suited for storing data for relatively short periods of time.

We created a glove with conductive thread embroidered into its fingertips. While wearing the glove, we can swipe across a smartphone, while it is in our pocket. The smartphone can then sense which direction you are swiping in and pick up or dismiss a call, or pause or play your music. This can be useful if you are driving and you don't want to take your smartphone out of your pocket.

We started on this project in early 2017 as part of my PhD research. The team consists of myself and my advisor Professor Shyam Gollakota. We are both based in the Department of Computer Science & Engineering at the University of Washington.

To the best of our knowledge, we are the first to explore the idea of storing data into clothes using the magnetic properties of conductive fabric.

We can store 225 different codes on a shirt cuff. This is sufficient for many inventory tagging and authentication applications.

We have not decided on whether we wish to commercialise this.

We used off-the-shelf conductive threads for our experiments. As it turns out, all conductive threads can be magnetised as they contain traces of metal. We used a conductive thread that yielded a high magnetic field strength and was also thin enough to be used with a sewing machine.

No. All modifications can be done at the software level. We could develop an app today and push it to your smartphone, and you would be able to read data from your clothes. We have some sample Android code available on the project website that allows you to see magnetometer readings.

Our lab completed a project that involved the use of conductive fabrics to turn a shirt into an antenna that can communicate data over the air by absorbing or reflecting ambient FM radio waves.

We have yet to collaborate with other institutes or private companies on projects related to smart fabrics. However, we would be open to collaboration should the right opportunity arise.

There are two major applications here. First, imagine if a department store wanted to tag clothing with a unique identifier, they could use a barcode, which is visually obtrusive or an RFID tag, which has to be read with an expensive RFID reader. With our approach, all clothes can be unobtrusively tagged with a unique identifier that is embedded into the fabric. Furthermore, all of our tags can be read with an everyday smartphone. Second, what we envision is for uniformed employees like doctors, or hotel or mall employees, to have our specialised fabrics embedded in their uniforms. So, instead of scanning an RFID keycard to get to work every day, these employees can instead scan the cuff of their shirt against a reader and easily access authorised areas.