Capacitive touchscreens are often preferred over resistive touchscreens because of their superior level of responsive as well as durability. They are called “capacitive” because they detect and identify touch commands by measuring capacitance. If you touch the screen of a capacitance touchscreen, your finger will absorb some of the device’s electrical current, thereby changing its capacitance.
While all capacitance touchscreens use this same technique to identify touch commands, there are different types of capacitance technology, each of which functions in a different way. Some of the most common types of capacitance touchscreen technology include projected capacitance, self-capacitance and mutual capacitance, the latter of which we’re going to explore in this blog post.
Overview of Mutual Capacitance Touchscreen Technology
Mutual capacitance touchscreen technology is technically a type of projected capacitance technology. But mutual capacitance differs from standard projected capacitance in the sense that it creates mutual capacitance on a grid of columns and rows.
When you touch a mutual touchscreen device, some of the electrical current running through the adjacent columns and rows is transferred to your finger, thereby lowering the capacitance at that specific intersection of the grid.
Mutual capacitance touchscreens essentially create a capacitor at each intersection where the columns and rows meet. Therefore, a mutual capacitance touchscreen with 16 rows and 14 columns would feature 224 capacitors. Touching the display, of course, causes the capacitance at the nearest intersection to drop.
Mutual Capacitance Supports Multi-Touch Commands
Because it creates mutual capacitance on grids, mutual capacitance touchscreens support multi-touch commands. In other words, you can tap or touch two or more areas on a mutual capacitance touchscreen device to trigger a command. Multi-touch commands open the doors to a whole new world of command possibilities. Pinching the screen, for example, may allow you to zoom in or out, depending on the direction in which you pinch.
Of course, mutual capacitance isn’t the only touchscreen technology that supports multi-touch commands. Self-capacitance also supports the use of two or more simultaneous points of contact.
Like all forms of projected capacitance touchscreen technology, mutual capacitance offers a high level of touch sensitivity as well as a high level of touch accuracy. For these reasons and others, projected capacitance touchscreens are often preferred over surface capacitance touchscreens.
To recap, mutual capacitance is a form of projected capacitance touchscreen that measures the capacitance at intersections on a grid to identify where and when a touch command occurred. Because of its design, it’s able to detect multiple simultaneous touch commands.