Bending Detection Flex sensors are passive restrictive devices that can be used to detect bending or flexing. A Bending Detection flex sensor is a sensor that measures the amount of deflection or bending. The sensor is attached 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 a magnetometer, and often called flexible potentiate . The flex sensors are normally attached to the glove using needle and thread. They are usually in form of strips. They can be made unidirectional and bidirectional.

HOW IT WORKS:

One side of the sensor is printed with a polymer ink that has conductive particles embedded in it. When the sensor is straight, the particles give the ink a resistance of about 30k Ohms. When the sensor is bent away from the ink, the conductive particles move further apart, increasing this resistance (to about 50k-70K Ohms when the sensor is bent to 90°, as in the diagram below).

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When the sensor straightens out again, the resistance returns to the original value. By measuring the resistance, you can determine how much the sensor is being bent.

Types & application of Bending Detection Flex sensor :

  • Types of sensor:

  1. Conductive ink based flex sensor
  2. Fibre optic flex sensor
  3. Capacitive flex sensor
  • Application of sensor:

  1. Human Machine Interface devices
  2. used in security systems

Use of  Bending Detection flex sensor with pictures:

flex sensor uses carbon on a strip of plastic to act as a variable resistor. The resistance changes by flexing the component. The sensor bends in one direction, the more it bends, the higher the resistance gets.

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Picture of flex sensor:

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SPECIFICATIONS :

  • Life Cycle: >1 million
  • Height: 0.43mm (0.017″)
  • Temperature Range: -35°C to +80°C
  • Flat Resistance: 25K Ohms

    Resistance Tolerance: ±30%

    Bend Resistance Range: 45K to 125K Ohms

    (depending on bend radius)

    Power Rating: 0.50 Watts continuous. 1 Watt Peak

The Materials needed for the simple flex project are:

  1. Arduino UNO
  2. Breadboard
  3. Flex Sensor
  4. Led
  5. 10K Ohm & 220 Ohm resistors

Connection with Arduino Uno :

CODE:

  SERIAL MONITOR:

Video:

 

Purchase:

  1. FSENS Flex sensor 2.2 Inches
  2. FS22 Flex sensor 2.2 Inches
  3. Bend sensor 2.2
  4. Flex sensor 4.5
  5. Generic SNSR_2 4.5 Inch Flex Sensor for Robotics

3D cad file :

You can download it from here. …

Similar sensor:

  • BAND SENSOR

OTHER IDEAS:

  • You can make your hand a gaming controller.
  • You can make your own prosthetic hand which can be controlled by a glove with flex sensor.
  • You can make a hand remote for your television, etc…