Adafruit Industries 1070

Short Flex Sensor | Adafruit Industries 1070

This sensor can detect bending in one direction. They were popularized by being used in the Nintendo PowerGlove as a gaming interface. These sensors are easy to use, they are basically resistors that change value based on how much their flexed. If they're unflexed, the resistance is about 25K. When flexed all the way the resistance rises to 100K. They're pretty similar to FSRs so following this tutorial will get you started. You can use an analog input on a micro-controller (with a pullup resistor) or a digital input with the use of a 0.1uF capacitor for RC timing. The bottom part of the sensor (where the pins are crimped on) is very delicate so make sure to have strain relief - such as clamping or gluing that part so as not to rip out the contacts!