In terms of popularity, capacitive touchscreens have surpassed resistive touchscreens. They typically offer higher-resolution images as well as increased responsiveness when compared to their resistive counterparts. Unlike resistive touchscreens, though, capacitive touchscreens are designed with a transparent coating. What’s the purpose of this transparent coating exactly?
Overview of Capacitive Touchscreen Coatings
Most capacitive touchscreens are designed with a transparent coating of an electrically conductive material. The most common material used for these coatings is indium tin oxide (ITO). ITO is both transparent and electrically conductive, making it ideal for use in capacitive touchscreens.
Because it’s transparent, you typically can’t see the coating over the surface of a capacitive touchscreen. The coating is applied to the top layer, which is made of glass. Therefore, it goes unnoticed by most users. Even though it’s invisible, however, coatings are still an important feature for capacitive touchscreens.
Detects Touch Commands
The transparent coating used in capacitive touchscreens plays an essential role in the detection of touch commands. All capacitive touchscreens work by measuring an electrostatic field. When turned on, they emit a small electrical charge across the top layer while simultaneously measuring the charge’s voltage. When the voltage increases, the capacitive touchscreen device will identify this change of capacitance as a touch command.
Without a transparent and conductive coating, capacitive touchscreens won’t be able to detect touch commands. The coating is conductive, meaning electricity can flow through it. Touching the interface of a capacitive touchscreen will draw some of its voltage to your finger.
The transparent and conductive coating allows electricity to move from the capacitive touchscreen’s interface to your finger. Your finger will absorb some of the voltage, after which the capacitive touchscreen will respond by registering a command in the area where you touched. If a capacitive touchscreen doesn’t have a conductive coating, it won’t register or respond to your touch commands.
Protects Against Scratches
While capacitive touchscreens use a transparent coating primarily to detect touch commands, it also protects them from scratches. All touchscreens can develop superficial scratches, and capacitive touchscreens are no exception. Fortunately, the transparent coating helps to protect them from scratches.
The transparent coating acts as a barrier between a capacitive touchscreen’s glass layer and the surrounding environment. You won’t actually touch the glass layer. Rather, you’ll touch the transparent coating. Therefore, it will protect the capacitive touchscreen’s glass layer from scratches and other forms of superficial damage.