A flex sensor or bend sensor is a

sensor A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends ...

that measures the amount of

deflection Deflection or deflexion may refer to: Board games * Deflection (chess), a tactic that forces an opposing chess piece to leave a square * Khet (game), formerly ''Deflexion'', an Egyptian-themed chess-like game using lasers Mechanics * Deflection ...

bending In applied mechanics, bending (also known as flexure) characterizes the behavior of a slender structural element subjected to an external load applied perpendicularly to a longitudinal axis of the element. The structural element is assumed to ...

. Usually, the sensor is stuck to the surface, and resistance of sensor element is varied by bending the surface. Since the resistance is directly proportional to the amount of bend it is used as

goniometer A goniometer is an instrument that either measures an angle or allows an object to be rotated to a precise angular position. The term goniometry derives from two Greek words, γωνία (''gōnía'') 'angle' and μέτρον (''métron'') 'me ...

, and often called flexible

potentiometer A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat. The measuring instrume ...

Types of flex sensor

*Conductive ink based flex sensor *

Fibre optic An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to ...

flex sensor *

Capacitive A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of a c ...

flex sensor *

Velostat Velostat, also known as Linqstat, is a packaging material made of a polymeric foil (polyolefins) impregnated with carbon black to make it electrically conductive. It is used for the protection of items or devices that are susceptible to damage from ...

flex sensor (popular among hobbyists)

Applications

Flex sensors are used in wide areas of research from computer interfaces, rehabilitation, security systems and even music interfaces. It is also famous among students and hobbyists.

Human Machine Interface devices

dataglove A wired glove (also called a dataglove or cyberglove) is an input device for human–computer interaction worn like a glove. Various sensor technologies are used to capture physical data such as bending of fingers. Often a motion tracker, such a ...

is human-computer interaction device that is made possible by flex sensors. Deflections of a dataglove are measured via its flex sensors embedded in the glove.

Rehabilitation Research

In rehabilitation research, wired gloves or datagloves are used to record joint movement.

Security Systems

Movement of doors is monitored by placing the sensor at the hinge. Also, damage to metal structures can be identified using the sensor.

References

* {{cite web, title=Flexion, url=http://www.sensorwiki.org/doku.php/sensors/flexion Sensors