Touchscreens are used in countless consumer and commercial applications. They are devices that, as the name suggests, support touch-based commands. You can find touchscreens in smartphones, tablets, smart appliances, human machine interfaces (HMIs) and more. While they all support touch-based commands, though, some of them use different technologies than others.
Capacitive is the most common touchscreen technology. It leverages a uniform electrostatic field to detect touch commands. In addition to capacitive, there’s also resistive and surface acoustic wave (SAW). What’s the difference between resistive and SAW touchscreens exactly?
What Is a Resistive Touchscreen?
A resistive touchscreen is a type of touch-controlled device that features two layers of a resistive material, both of which have electrodes. Electrodes are added to the underside of the top layer, and they are added to the top side of the top layer. In other words, the sides with the electrodes will face each other.
Resistive touchscreens work using a simple method of operation. The two layers used in a resistive touchscreen are separated by air. Performing a touch command will press the top layer into the bottom layer. Upon touching each other, their respective electrodes will complete a circuit at the area of the touch command. This will allow the resistive touchscreen to identify when and where the touch command occurred.
What Is a SAW Touchscreen?
A SAW touchscreen is a type of touch-controlled device that leverages sound waves to detect touch commands. They are designed to produce ultrasonic sound waves. The ultrasonic sound waves will travel across the display interface while being “picked up” by corresponding sensors. In other words, SAW touchscreens monitor the ultrasonic sound waves.
If you perform a touch command on a SAW touchscreen, your finger will disrupt the ultrasonic sound waves in the area of your command. The sensors will notice this disruption, and the SAW touchscreen will respond by registering a touch event in the location of your touch command.
Differences Between Resistive and SAW Touchscreens
Resistive and SAW touchscreens both consist of touch-controlled devices; they simply use different underlying technologies to detect touch commands. Resistive touchscreens are made of two layers that feature electrodes. SAW touchscreens, on the other hand, are made with ultrasonic sound wave generators and sensors.
Capacitive is still the most common touchscreen technology. But that doesn’t mean it’s the only touchscreen technology. Other touchscreen technologies include resistive and SAW, both of which identify touch commands using a unique and different method.