Researchers at the University of Waterloo's School of Computer Science have come up with what they claim could make interactive wearable electronics more readily accessible: through-fabric displays dubbed PocketView.
"The idea is not to show all the information that you would normally see on your smartphone display,” says Antony Albert Raj Irudayaraj, PhD researcher and lead author, of his team's work. "These are displays that show minimal information. That’s good enough if you’re walking or biking, for example, to show basic navigation instructions. Or let’s say you received a message and don’t want to divert attention from what you’re doing. You can peek at the display and see the notification."
The actual technology behind PocketView is refreshingly simple: An LED matrix which is positioned, as the name suggests, in the user's pocket. If a notification is required, the LED matrix shines a low-resolution icon — something immediately recognisable, like an alarm clock or a direction arrow — brightly enough that it displays through the fabric.
After running a survey to see if enough people would be interested in seeing notifications even if their phone is in their pocket, the team set about checking if a common LED matrix connected to an Arduino Mega could shine brightly enough through ten common fabric types - including denim, flannel, velvet, fleece, and spun-bond fibers. While not all fabrics proved suitable — denim, in particular, failed to let enough light through - the results showed enough promise for prototyping.
The prototype PocketView display is built around an Adafruit 2872 RGBW Neopixel 8x8 LED matrix display, coupled with an Arduino Pro Mini microcontroller and an HC-05 Bluetooth module for connection to a smartphone app. "The form factor of this prototype can represent a through-fabric display housed in a custom phone case, or as a stand-alone device carried in the front pocket resembling a wallet (with the phone placed in a back pocket or bag)," the team explains.
"Our single-sided prototypes must be inserted into a pocket with the LED matrix facing out to work as a display. This also provides an explicit way to silence or hide a through-fabric display by simply changing the orientation. The Android app sends a bit stream required to display appropriate imagery on the matrix display. This would enable an Android app to sync with other apps like health, email, and calendar to display appropriate through-fabric content."
Later variations on the theme include an LED matrix built into the case for Bluetooth headphones, an LED strip placed in the body of pen, a smaller matrix packed into a car remote, and a matrix-equipped smartphone case. "The different sizes are important," explains co-author Nikhita Joshi, "because so much women's clothing has tiny pockets. A phone in the front pocket can be uncomfortable. So having something small just gives people way more options. We created a whole variety of form factors that would also be suitable for smaller pockets that are common in women’s clothing."
"Obviously, we’re focused on the tech and programming side of the invention," adds Daniel Vogel, associate professor of computer science at Waterloo, of the team's work. "But even just as a fashion accessory, it's something people told us they want. People could use it at clubs or in sports or in so many other ways. It's such a simple thing but also such a radical idea that has so much potential."
The PocketView paper has been presented at the ACM Symposium on User Interface Software and Technology (UIST '21), and is available to download under open-access terms as a PDF.