“Most drawing tools/pens we use today allow only a one-way flow of ink, and we are oblivious to how the content of the tool came to exist inside. What if we could not only have control over the outflow of the ink, but also have influence on what goes inside? Indeed, old fountain pens served as both tools to pick up and release the ink, and paintbrushes still preserve that function. We bring back this tradition of a drawing tool as both an input and output device, but instead of picking up the liquid ink, I/O Brush lifts up and captures photons.

In our current prototype, the brush houses a small CCD video camera in its tip with a ring of white LEDs around it. Force sensors are also embedded inside of the brush, measuring the pressure that is getting applied to the bristles. When the brush touches a surface, the lights around the camera briefly turn on to provide supplemental light for the camera. During that time, the system grabs the frames from the camera and stores them in the program.”

http://web.media.mit.edu/~kimiko/iobrush/
http://web.media.mit.edu/~kimiko/iobrush/
http://web.media.mit.edu/~kimiko/iobrush/

Check the video. Awesome.