Craft stores have these wonderful realistic styrofoam skulls around Halloween time. Here we’re using LED matrices for just the eyes, no mouth (the “roboface” sketch will work all the same). We simply carved out the eye sockets to the back and pushed the LED matrices through. The eyes peer around and blink:
Level up: add a joystick to move the eyes…or if you’re really crazy, use a webcam or a Kinect sensor on a PC (connecting to the Arduino through USB) to make the eyes automatically follow victims around the room.
This Jack-o’-lantern (another craft store find made of foam) uses all five matrices (eyes and mouth). Note the 45 degree installation of the eyes. Try to think how you can break free of simple grids and alignment:
This glass head (which originally inspired the project) came from Pier 1 Imports. The addition of a bundled up length of Flowing Effect EL Wire creates an impression of coursing blood or a pulsing brain:
The matrices were held in place with hot-melt glue, which can be cleanly removed later using a Q-Tip dipped in rubbing alcohol.

Lesson learned: at 200 milliamps each, these displays get warm enough to soften the glue. Nothing fell off, but it’s something to keep in mind. If the situation permits, use the matrix backpacks’ mounting holes (obviously this won’t work with the glass head).
Another thought was to glue the displays to a mask, which could be worn under a “morph suit” — the LEDs are extremely bright and will show through the thin fabric:
It’s an interesting concept but still needs some work. Placing the LED backpacks directly over one’s mouth presents a problem: moisture from exhaled breath is conductive enough to confuse the address pads on the backpacks, and they quickly end up all showing the same image! A small blob of hot-melt glue covering the “open” address pads took care of this, but there may still be other issues lurking…the whole thing should probably be potted or enclosed, sealed off from breath and perspiration.

Level up: have the mouth move in sync with the wearer’s own…perhaps a pressure or flex sensor under the chin, or using a microphone based on volume.
Last updated on May 04, 2015 Published on Oct 13, 2012