There are a few things historically difficult to make a robot do. Stairs, of course, are the obvious problem. But realistic blinking behavior is harder than you might think. At first, it might seem frivolous and simple to have a robot blink, but according to Italian scientists, it is both more important and more difficult than you probably think.
Blinking is a nonverbal cue when humans communicate. The post quotes a Finnish researcher:
While it is often assumed that blinking is just a reflexive physiological function associated with protective functions and ocular lubrication, it also serves an important role in reciprocal interaction.
