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.

Why Choose Capacitive Sensing

There are many reasons why capacitive has become the preferred touch-sensing technology for touchscreen devices. First, it offers a highly responsive interface that’s very sensitive to touch commands. Even a light touch with minimal pressure will register a touch, as this still allows electricity to transfer from the device to your finger. This is in stark contrast to resistive touchscreen devices, which require a heavier touch with more pressure.

Capacitive touchscreen devices are also incredibly durable, meaning they’ll last for a very long time. This is partly because they use capacitive sensing to identify touch rather than pressure. With capacitive sensing, there’s less pressure exerted upon the device’s interface, so it wears more slowly.

It’s important to note, however, that capacitive touchscreen devices typically don’t work with a stylus. Stylus pens are made of non-conductive material like plastic, so they won’t transfer electricity from a capacitive device, nor will they allow the device to register a touch command. The only exception is a special capacitive stylus, which are designed with a conductive material.