The c))motion screen
Basically it's ventilation covered by a plastic material that behaves in a similar way to bi-metalic strips. i.e. When it gets warm they bend and the ventilation opens.
And here it is in action:
Too many mathematicians on here not to share this... ( Direct Link) ( via gormano)
This has to be the most amazing thing ever... http://www.youtube.com/watch?v=tgbNymZ7vqY ( Direct Link)