At National Aquarium (Baltimore) we constructed a purely optical computer touchpad on one of the viewing windows of the main exhibit pool. The touchpad operates by detecting the touches of the dolphin’s rostrum by illuminating the window with infrared light, which is not only invisiible to dolphins (as well as humans) but also penetrates water very shallowly. By monitoring reflections in the infrared channel we were able to ascertain how close the rostrum was to the actual window and in what exact location. Our software then converted this into a standard mouse input for the computer.

Meanwhile, the computer is connected to a rear-view projector as a second screen. Any dolphin touch on that screen would appear to the system as a mouse click at that location in the second screen.

The game you observe in this video was a “whack-a-fish” game. The video shows the first exposure of Forster, a young male dolphin, to the touchscreen or any video game of any kind. Or, in fact, to live fish, which he has never seen. You can see him playing with the game immediately.

The touchpad was created and programmed by Ana Hocevar and Marcelo Magnasco, following design input from Diana Reiss.