"We spend so much time talking about sensing things less mechanical, that is is easy to forget the accelerometer isnt the only part in town. The flex sensor is one of those parts often overlooked by the advanced user. But what if you need to check if something bent? Like a finger, or a doll arm. (A lot of toy prototypes seem to have this need).
Anytime you need to detect a flex, or bend, a flex sensor is probably the part for you...."