If you gaze into the abyss, the abyss also gazes into you. Or, in this case, an adorable, minimalist facsimile of a face, rendered in patches of ferrofluid -- nanoparticles of ferromagnetic material suspended in a carrier liquid.
And you don't have to do the first gazing, either: Eye Catcher, a project by Lin Zhang and Ran XieInteractive Architecture Lab at University College London, is desperate for your attention; so much so that the artwork will slide along the wall next to a passerby, hoping to catch their attention, seemingly suspended by magic. When they stop to look, two spots -- like eyes -- rise out of the puddle of ferrofluid at the bottom of the frame to look back.
To create this effect, the bulk of the work is tucked away into the crawlspace: a robotic "puppeteer" that controls the frame with strong magnets. A pinhole camera hidden in the frame detects the motion of people passing by; this allows the robot to move in unison with the human, moving when they move and stopping when they stop.
It also allows software to map the face of the viewer when they stop to look at Eye Catcher, determining both the position of their eyes and their facial expression, and mimicking both. When the viewer smiles, the ferrofluid eyes look cheerful; when the viewer frowns or pouts, they droop towards the bottom of the frame.
"Through a series of experimental films, photography and physical prototypes, the primitive effects of eye (and eye-like) stimuli have been investigated," wrote project supervisor Ruairi Glynn. "The Eye Catcher project in its conclusion has developed a novel expressive interface where emotion recognition algorithms read audience faces and in-turn trigger the animation of a face formed of ferrofluid."