A metal clothing button and a button hole that works as state switch. When it is fastened, the connection is made, and if you open the button, the connection gets broken.

*This sensor is inspired by the Swatch exchange sample “Button Switch” by Ricardo O’Nascimento

Step by Step

Cut a hole on the fabric. Make sure the hole is big enough for the button you have. You can use non-metal (non-conductive) button too, but I think it is better to use metal button to have stable connection.

Sew the button hole with conductive thread. In this example I used Statex silver plated 4 ply thread as it is nicely thick and soft. Stitch around the hole with plain stitch first. Then stitch the edges of the hole by wrapping around the open edges.

continue the stitch to the bottom of the fabric. This will become a point to connect to your multimeter probe, or further connection to microcontrollers or circuits.

Mark the position of the button.

Fasten the button with conductive thread just like how you do the normal buttons with normal thread. Continue stitching the thread down to the bottom of the fabric so you can connect your probe.

When you close the button, the connection is made, and when you open it, the connection brakes. Unlike push buttons, this sensor keeps the state unless you change it. For example, you can use this sensor as on/off switches.