Cheap flex sensors with electrostatic bags and masking tape

From Hack a Day: http://hackaday.com/2012/06/04/making-flex-sensors-on-the-cheap/

Instructable: http://www.instructables.com/id/DIY-Bend-Sensor-Using-only-Velostat-and-Masking-T/

Flex sensors change their resistivitiy when bent. These are DIY flex sensors made with electrostatic bags (Velostat) and masking tape. A zip tie is used for reinforcement. Two wires are attached to strips of the electrostatic material, with two more layers loosely sandwiched between these. This is taped together with a zip tie added.