For this project to emulate the emotion of excitement (possible of a young child) using a servo as a representation of physical motion. Two buttons are used increase (give sugar) or decrease (sing lullaby) excitement.
Below is the link to my project:
https://drive.google.com/open?id=0BxAGrufmmWthTWtJRGt6LW5QWTQ
I think this project is a great example of expressing a lot of emotion without needing a complicated mechanism. The expression of excitement is perfect, but if you were to continue working on this, I would recommend trying to express sleepiness with a bit of a more intricate motion. Maybe the servo could start to drift to sleep, only to shake itself awake – and if you gave it more of the lullaby button, it could fall asleep and snore.