If you need to measure bend, or deflection, a flex sensor is the perfect sensor for the job. By attaching it to a surface, you can measure the deflection of that surface. The resistance of the flex sensor changes as it is being bent.
However, flex sensors can be quite expensive and can be damaged easily.
Alternative for a flex sensor
While there isn’t a particular sensor that is available on the market as a direct alternative of the flex sensor (as well as being cheaper), there are many ways to create your own that will be able to mimic the functionality of the flex sensor. This way you can save money as well as learn new ways to create a flex sensor.
One cheap and readily available component that can be used to recreate a flex sensor is a potentiometer. A potentiometer is a three terminal resistor whose resistance can be varied by turning a knob.
Another alternative is to use materials that you will have available in your home. Materials such as paper, tin foil/aluminium, velostat plastic bags, and masking tape.
How to make a flex sensor at home
Below are some great resources on how to make your own cheap alternative for a flex sensor using components such as a potentiometer, or materials that you will definitely have lying around the house.
Alternative DIY flex sensor method #1: Potentiometers
Using potentiometers to make a flex sensor glove;
The end result of this is not going to look like a flex sensor, however, it will have the same functionality. Also, this method was used for a glove, but you can easily use the same components and materials for other projects. Check link below for an in-depth look at how to make an alternate flex senor using potentiometers.
https://www.instructables.com/DIY-Cheap-and-Accurate-Alternative-for-Flex-Sensor/
Alternative DIY flex sensor method #2: Random materials
You might never have considered ever using paper and tin foil/aluminium to make an alternative for a flex sensor. But, these cheap and readily available materials are perfect for exactly that. The end product will have the same form of a flex sensor that you will be after as well.
Using paper and tin foil/aluminium method #1:
Using paper and tin foil/aluminium method #2:
https://www.hackster.io/Shahirnasar/simple-homemade-flex-sensor-ff54f0
Using velostat plastic bags and masking tape:
Other alternatives for a flex sensor
If you only require the resistance to be varied, there are many sensors/transducers that are available that can be an alternative for a flex sensor which include;
- Light Dependent Resistors (LDRs)
- Force sensors
- Potentiometers
- Piezoelectric sensors
- Thermistors
