Self-Capacitive vs Mutual Capacitive Touchscreens

Touchscreen devices that measure a uniform electrostatic field to detect touch commands are known as capacitive touchscreens. During operation, they project a small electrostatic field across the display interface. When a conductive object, such as a bare finger, touches the display interface, the voltage of the electrostatic field changes. Capacitive touchscreens are able to detect touch commands by looking for changes in the electrostatic field.

There are several types of capacitive touchscreens, however. Two of the most common types include self-capacitive and mutual capacitive. Both self-capacitive and mutual capacitive touchscreens use an electrostatic field to detect touch commands. With that said, they differ in a few key ways.

What Is a Self-Capacitive Touchscreen?

A self-capacitive touchscreen is a type of touchscreen device that features a grid of capacitance sensors, with the rows and columns operating separately and independently of each other. Self-capacitive touchscreens are designed to measure the voltage or capacitance of a load. They project a uniform electrostatic field across the display interface. When you perform a touch command, the self-capacitive touchscreen will identify it by looking for a change in the voltage on the grid of capacitance of sensors.

What Is a Mutual Capacitive Touchscreen?

A mutual capacitive touchscreen is a type of touchscreen device that automatically forms a capacitor as the junction of a grid. Mutual capacitive touchscreens leverage the fact that when two conductive objects are near each other, they can hold a charge. Like self-capacitive touchscreens, they feature a grid of capacitor sensors. Mutual capacitive touchscreens have rows and columns of capacitor sensors, which together creates a grid. When you touch the display interface, a capacitor will be formed at the intersection of the nearest grid and row.