E-Textile Pressure Sensor

Pressure sensor is a type of analog sensors that produces continuous signals. It senses the amount of pressure, and convert it into digital signal.

If you are using piezo-resistive material, e.g. anti-static foam. The current comes from one layer of conductive material, and goes across the piezo-resistive materials to the other layer of the conductive materials. When being pressed, the conductors in the piezo-resistive material are squeezed tighter, allowing current to pass through easier. This results in an expression of sensitivity to pressure, the resistivity decreases and conductivity increases as pressure is applied.

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If you are using resistive material, e.g. Velostat. The area of contact between conductive layers and resistive material increases under pressure. A better contact reduces resistance, and allows current to pass through easier.

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This tutorial guides you to create a simple e-textile pressure sensor. Click here to see more examples following the same principle.

Watch the tutorial

------------content of this video-----------

00:00​ - intro

01:23​ - prepare materials

02:22​ - making with template

03:49 - testing

Read the tutorial

Materials

  • Anti-static foam (or other (piezo)resistive material, velostat would work great)

  • Copper coated fabric (or any other conductive material)

  • Iron-on adhesive

  • Non-conductive fabric

  • Non-conductive thread

If using template, find out the elements​ in below picture

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Tools

  • Iron

  • Needle (or sewing machine)

  • Scissor

  • Baking paper

Making steps 

Skip to step 4. if using the template.

1. Iron the adhesive to the back of the copper fabric

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2. Cut the copper fabric into two squares each with an extended leg, and cut two pieces of the non-conductive fabric to be the substrates 

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3. Cut a square of anti-static foam that is larger than the square of the conductive fabric

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4. Iron to fuse the copper fabric on the non-conductive fabric

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5. Sandwich the anti-static foam in between the copper fabric.

Make sure the foam has fully spaced the two conductive layers apart  to avoid short circuit

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6. Secure the circuit by sewing the edge of the non-conductive fabric.

Double check to make sure there is no chance for the two layers of conductive fabric to contact with each other! Otherwise your sensor has a risk of short circuiting!

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7. Your pressure sensor is done!

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8. To test the sensor, set the multimeter to a proper resistance measurement setting, you should see the ohm reading changes when pressing the sensor.

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More examples following this principle

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