Body weight measurement

I am trying to make an insole (shoe sole) system to measure body weight. Unable to find a suitable sensor for that. Please suggest a suitable sensor that can monitor body weight and which work better than force sensitive resistors in accuracy and lesser in size compared to load cells.

I think those are the two options (force sensitive resistors and load cells). I think there is nothing else.

Maybe some form of small inflatable insole? measure the air pressure and you may be able to calculate the weight!

Load cells are typically just made up of a bunch of strain gauges. You could easily make your own "load cell" that is really tiny and designed to fit in a shoe. There's plenty of examples out there on how to hook up a strain gauge to an arduino.

Also, FYI, it will be tough to measure weight through something in the sole of a shoe for three reasons:

  1. The weight of the body is distributed over the area of the entire foot. Sure, more of that weight is concentrated at the heel, but some of it is also concentrated up by your toes. In order to accurately measure the weight, you will have to capture the pressure of the entire foot, not just one part of it. So the entire sole of the shoe will have to be separated from the rest of the shoe by your sensor.

  2. You will only be able to measure weight when the person is standing still. There are a lot of dynamic forces when you are walking/running that will change what your sensor sees as "weight". Imagine jumping up and down on a scale and how that effects the "weight" it measures.

  3. How tight you tie your shoes will effect the measurement. When you tie your shoes, you are putting pressure on your feet. If you put a sensor at the bottom of the shoe, your pressured feet will in turn pressure the sensor, making it think there is more "weight".