A Crash Course on Capacitive Sensing and How It Works

Many touchscreens rely on capacitive sensing to detect touch commands. Even if you're unfamiliar with the technology, you've probably used one of these touchscreens before. Known as capacitive touchscreens, they've become the world's most popular type of touchscreens. It's estimated that over nine in 10 touchscreens use capacitive sensing to detect touch commands. For a better understanding of capacitive sensing and how it works, keep reading.

What Is Capacitive Sensing?

Capacitive sensing is exactly what it sounds like: the ability to detect changes in capacitance. It's the fundamental technology behind capacitive touchscreens. Capacitive touchscreens receive their namesake from their ability to detect changes in capacitance. They leverage "capacitive sensing" to determine when and where touch commands occur.

How Capacitive Sensing Works

You might be wondering how capacitive sensing works exactly. All capacitive touchscreens feature a sensor that's constantly measuring the capacitance of the display interface. The display interface is the layer that you touch to perform commands. When you turn on a capacitive touchscreen, it will generate a uniform electrostatic field across the display interface.

By default, the electrostatic field is uniform. Touching the display interface, however, will absorb some of it. The human body is electrically conductive. When you touch something that has a charge, your body will absorb some of the charge. Capacitive touchscreens, of course, have a charge - the electrostatic field over the display interface. Upon touching it, the "capacitance" of the electrostatic field will change.