The idea of using the RCX programmable brick ('Pbrick') in building
LEGO-creatures that convey 'feelings' leads to the logical conclusion
that these creatures need to have some way of expressing their
feelings. We do not pretend to be able to incorporate anything even
remotely resemblant to real emotions like anger, fear, love etc. in a
LEGO-robot, but fortunately this is not our goal anyway. Our goal is
to develop special LEGO-models with special features of behavior that
might give us the impression that they actually possess some
sort of emotional intelligence.
Humans display their state of mind through a variety of gestures, body
language and facial expressions. As a human face alone often reveals
the person's mood we have chosen to focus on this part of the human
anatomy as an early example. Since much of the expressiveness of a
face lies in the mouth and the eye surroundings we engaged in building
a LEGO-face with two degrees of freedom: a mouth and a pair of
symmetric eyebrows.
A mouth is hardly a rigid as the ordinary LEGO Technic bricks, so we
came up with the idea of using a thin, pneumatic tube instead. The
tube is forced into an upwards (
) or downwards (
) bend
to form different mouth expressions from happy through sad to
angry. The eyebrows can in an analogous manner be simultaneously
lifted or lowered to form various combinations with the mouth
emphasizing or suppressing the expression of the mouth.