Arduino animatronics tutorial

Those bend sensors (also called flex sensors) are pretty durable if they are used properly- they were used in the old Nintendo PowerGlove. You need to be careful soldering the tabs on them and they need heat shrink over the connections to act as a strain relief since that's where they are most likely to be damaged. It's also best to put a sleeve over the sensor before using in a glove application or anything that could see some abrasion- the metal pads on the sensor need to be facing on the outside of the bend in order for it to work properly and those pads can be worn off and/or damaged if left unprotected. SpectraSymbol (the manufacturer) rates them at over one million cycles.

They can be used for all kinds of applications- anything where you would use a variable resistor (potentiometer). You can use it to track servo movement or brightness of an LED to the amount of bend in the sensor, use it control the speed of a motor, etc. When using them in this manner they can be a bit noisy, especially if your wires running to the sensor are long or unshielded. By noisy I mean the readings from the sensor can jump around quite a bit so you need to average readings in your code or apply a filter- otherwise if you're using it to control an exact servo position the servo will jitter a fair bit. I tend to use them as an input device that reads the amount of bend in a finger and then triggers a function- sort of like a switch. You set a threshold in your code and once the sensor reaches that threshold an action is performed.