Staring at the Wall for Fun

With the rise of smartphones came the widespread adoption of the touchscreen as a means of human-computer interaction. Now, touchscreens are rapidly becoming ubiquitous — aside from your phone or tablet, you can also find them waiting to take your order at a restaurant, check you out at the grocery store, or prepare your boarding pass for a flight. These screens tend to be on the smaller side due to the cost of scaling the underlying display technologies up.

So what is to be done when a room-sized interactive display is needed? And what if you do not want the characteristic black glossy appearance of a typical touchscreen, but want a display that blends in with whatever it is incorporated into? Enter OptiStructures, a new fabrication method devised by a research group centered at Carnegie Mellon University to create room-scale, interactive displays that seamlessly blend in with their environment.

OptiStructures consist of two primary advancements. In the first, a method was developed to create molds with optical fibers inserted and pushed to the surface. These optical fibers can be arranged into a grid, or any other configuration, to act as pixels for display purposes. The second advancement involves placing Fiber Bragg Grating (FBG) optical sensors in the same structure. These FBG sensors, also composed of optical fibers, can detect vibrations that are useful for collecting user input. These sensors can detect activity throughout the room, such as someone walking nearby, and they can also detect direct user input, such as tapping on the display surface.

The optical fibers are driven by LED arrays under computer control (an Adafruit Feather M4 Express board was used in the study). The control hardware and power source can be either behind a wall, or inside of a structure. The manufactured surfaces themselves only contain the optical fibers. This simplifies maintenance and upgrades of the display over time.

The researchers built what they call an “active wall” to test the new process. They built a rectangular mold with an injected fiber optic display and used it to replace a section of drywall in an existing wall. The wall was shown to respond to tapping, swiping, and knocking actions, and also was able to detect if someone was drilling, sawing, or hammering in the room.

The grid display on the active wall is somewhat irregular, perhaps indicating that the fabrication process needs refinement, but nevertheless is clear and very usable. In any case, OptiStructures looks like a solid idea for creating low-cost, room-scale interactive displays. I hope to see some more advanced implementations in the future.