Uses the principles of capacitance to detect touch or proximity

Capacitor is formed by two conductive plates separated by a dielectric material.

One plate is the sensor surface and the other is typically the ground plane.


AC voltage is applied to the sensor surface, creating an electric field around it.

This electric field extends beyond the surface of the sensor.

When a conductive object, like a finger, approaches the sensor surface, it disrupts the electric field. This change in the electric field causes a change in capacitance.

Signal processing unit analyzes the change in capacitance and determines whether a touch event has occurred.