How Capacitive Sensing Works

Capacitive sensing technology is used to power a countless touchscreen devices. Since the 1990s, it's been the most popular solution for touchscreen interfaces, allowing users to control a device using their finger or a stylus. Even with its ever-increasing popularity, however, many people still struggle to understand the concept of capacitive sensing and how it works. While different capacitive touchscreen devices use different components and software, most follow the same basic format to identify and register touch commands.

Overview of Capacitive Sensing

The defining characteristic of capacitive sensing technology is that it identifies the user's touch by measuring changes in capacitance (hence the name). With capacitive touchscreen devices, a small electrical charge is emitted across the surface of the touchscreen interface. Don't worry, it's not enough to shock or otherwise hurt. Rather, it's just enough electricity to allow the device to identify touch commands.

When you touch the surface of a capacitive device, some of its electricity will travel to your finger and throughout your body. This is due to the fact that a human body is an excellent conductor of electricity. When you touch something that's electrically charged - whether it's a capacitive touchscreen device or anything else - electricity will travel through your body. Capacitive devices use this phenomenon to identify touch commands. The device identifies a change in capacitance as some of its electricity is transferred to your body.