In this article i am going to share the information about the flex sensor and working principle behind it, it is a very much interesting sensor and have very good applications.



What is a flex sensor?

It is very simple to understand what a flex sensor is , if you rightly understand from the name itself. The name indicates that the sensor is flexible and able to sense changes by change in its flexibility i.e., bending.

           A flex sensor will give values according to its bending angle and bending length  and it is made up of some flexible material.



Why we need a flex sensor ?

Flex sensor has great applications in our day to day life. Flex sensor comes into application when you need a sensor where you want to check the angle deviation , straightness, etc. This feature will help us to get some unbelievable outputs that can be used for angular displacement measurement and in making VR game and in some musical instruments.

It can be used in constructing a glove that simulates in controlling a game with our hand gestures and it will be of great fun.

Physical looks of a flex sensor

It is a long 2 to 4 inch flexible sheet with 1cm width and 3mm thickness. It contains a conductor wire in it. It is two terminal device one is treated as ground and another one as a signal. The signal pin gives analog input to the micro controller. Both the pins are not specified as it is a kind of resistor and resistor is a bilinear element.



Electrical specifications

-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


Mechanical specifications

-Life Cycle: >1 million

-Height: 0.43mm (0.017″)

-Temperature Range: -35°C to +80°C


Working of a flex sensor?


Flex sensor can be simply understood as a variable resistor that changes the out put voltage based on the bending of the flex sensor.

Basic circuit diagram of flex sensor

It can be easily explained by its circuit diagram it is a impedance buffer and it is a single sided operational amplifier. The out ward voltage is controlled by the bending of the flex sensor and the Vout acts as a analog input for the microcontroller we use. It can be easily understand by the below figure.


Applications of flex sensor


«Gaming (Virtual Motion)

«Medical Devices

«  Computer Peripherals


I hope you understood the working and applications of the flex sensor from this article. Next i will be back with one more interesting module.

The comment box below is always open for you.

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