Using Conductive Paint to Create a Different Kind of Augmented Reality
Recently at Fusion we were approached by a client wishing to create an art display that would catch people’s attention and interact with them. We set out to create an interactive wall, but wanted to avoid using touch screens. Marketing displays are too often just tablets surrounded by decorated cardboard, and we wanted to avoid falling victim to consumers’ growing tablet fatigue. Consumers are no longer wowed by just having a tablet or touchscreen kiosk put in front of them. Instead we would try to do something new — conductive materials — with short-throw projectors to have digital animations pop up in real life. If done right, it would seem like the wall is coming to life.
We decided to do a prototype to test the concept and show the client our approach. We purchased and experimented with a number of conductive materials — conductive fabric, velostat (it’s a really cool material that changes its voltage as you change its form/compress it), conductive paint, copper tape, conductive thread, and more. We decided to focus on conductive paint for this prototype, with a simple demonstration of physical touch triggering digital animations. We created the Anatomy of Type.
An artist here at Fusion, Vanessa Tutka, handled the painting and preparation of our plywood canvas.
Vanessa first taped the board in its entirety to create a mask. she projected the artwork onto the board and slowly removed the tape with an exacto knife to expose the letters.
A generous amount of conductive paint was applied to each of the desired touch zones — 4 separate coats of it. The paint was sealed by using an acrylic based silver spray paint, making it look as a single continuous painting.
Our creative team used Adobe Flash to create the animations — we exported them to HTML5/Javascript so we could use them in our setup.
To detect the touch on the conductive paint, Vanessa fed a very thin bit of conductive thread, painted flat on the front of the wall, to the back. These were attached to thicker copper tape (easier to work with) and then finally fed into the MPR121 conductive touch board. The board would measure the variation in voltage (and timing in these changes) across the painting. When it changes, it would report back to an Arduino microcontroller which, in turn, would report over a serial port that a particular touch point was triggered.
To package the software together neatly, we created an Electron app. This allows us to get the ease and flexibility of an HTML web view, the power of node connecting to our hardware, and a portable package we can dump onto any computer once we were done writing the app.
The Electron app would launch, asking the user to select which COM port the wall was broadcasting on. As soon as it was selected, the Anatomy of Type would be launched and ready to go — sort of. In a more extensive build, we would probably include built-in tools to re-position and re-size the animations. Even slight movement of the board or the projector results in a large offset of where the animation should be. For now, I just adjusted some CSS via the built-in web console to get it looking good.
Everything came together for a smooth experience. When fullscreened, the projector wasn’t noticeable until after the animations started playing. A higher angled short-throw projector would make blocking the animations a rarity. The animations pop out on the board as if a cartoon came to life or as if they were magically painted before you. It provides the flexibility of a digital encounter with the tactile response of a physical experience. We look forward to doing more of these in the future!
