What Is a Surface Acoustic Wave Touchscreen?

Touchscreen technology has revolutionized the way in which we control electronic devices. Rather than using a keyboard, keypad, mouse or other traditional peripherals, you can control a touchscreen device by performing touch commands. Not all touchscreens use the same technology, however, to detect touch commands. Surface Acoustic Wave (SAW) is a relatively new type of touchscreen technology that, in recent years, has become increasingly popular. What is a SAW touchscreen exactly?

The Basics of SAW Touchscreens and How They Work

A SAW touchscreen is a type of touchscreen device that uses ultrasonic sound waves to detect touch commands. Like all touchscreens, they feature a digital display interface that’s responsible for both creating images as well as supporting touch commands. To control a SAW touchscreen, you press or tap your fingers on the display interface.

SAW touchscreens differ from other types of touchscreens in their method used to detect touch commands. Unlike other touchscreen devices, SAW touchscreens use ultrasonic sound waves to detect touch commands. They are designed with reflectors and transducers along the edges. The transducers emit ultrasonic sound waves that bounce off the corresponding reflectors.

When you perform a touch command, your finger will disrupt the ultrasonic sound waves traveling across the surface of the SAW touchscreen. The SAW touchscreen’s controller will notice this decrease in amplitude and register it as a touch command.

The Rise of SAW Touchscreens

While capacitive touchscreens continue to dominate the global touchscreen market — capacitive touchscreens account for over nine in 10 of all shipped touchscreens — SAW touchscreens have trended upwards in recent years. So, why are SAW touchscreens on the rise?

For starters, SAW touchscreens are highly responsive. Resistive touchscreens generally require a fair amount of force to register a touch command. If you don’t press down hard enough, a resistive touchscreen won’t register your touch command. SAW touchscreens, however, are more sensitive than their resistive counterparts. Even if you barely touch the display interface with little or no pressure, a SAW touchscreen should register your touch command.

You can also use a stylus to control a SAW touchscreen. Most touchscreens, including capacitive touchscreens, only register commands performed with a bare finger. If you use a stylus to tap the display interface, they won’t register your touch command. SAW touchscreens, on the other hand, work with a bare finger, a gloved finger or a stylus, which is one more reason why they’ve become so popular.