Touchscreen have revolutionized the way in which we control electronic devices. Rather than using a keyboard and mouse — or a similar externally connected peripheral — you can use your finger. There are many different types of touchscreens, however, one of the most advanced being surface acoustic wave (SAW). How do SAW touchscreens work exactly?
An Introduction to SAW Touchscreens
A SAW touchscreen is a type of touch-controlled device that leverages the properties of ultrasonic waves to detect a user’s touch commands. Like all touchscreens, they are designed to detect physical touches, which they’ll respond to with the appropriate action. SAW touchscreens are distinguished from all other types, though, by their use of ultrasonic waves. SAW is the only type of touchscreen technology, in fact, that uses ultrasonic waves.
How SAW Touchscreens Work
SAW touchscreens rely on ultrasonic waves to detect touch commands. Ultrasonic waves are essentially sound waves. Of course, you can’t hear the ultrasonic waves, nor can you see them. Nonetheless, the ultrasonic waves pass over the surface of the SAW touchscreen where they are able to detect touch commands.
Around the perimeter of a SAW touchscreen are components that emit ultrasonic waves. The ultrasonic waves create an invisible, uniform barrier over the display interface. When you tap or touch the display interface, your finger will disrupt the ultrasonic waves in that area. The SAW touchscreen will detect this disruption, at which point it will send the touch event to the embedded controller for processing.
Why SAW Touchscreens Are So Popular
While not as common as capacitive or resistive, SAW touchscreens have become increasingly popular over the years. They offer excellent image clarity that manifests in the form of high-quality images. All touchscreens produce images, but SAW touchscreens are able to produce clearer, more detailed images.
Another reason SAW touchscreens are popular is because they are long-lasting. Unlike with resistive touchscreens, they don’t have moving or otherwise mechanical parts. SAW touchscreens detect touch commands using ultrasonic waves. As a result, you can use them for a very long time without wearing down the SAW touchscreen’s components.
You can control a SAW touchscreen using either a finger or a stylus. Some touchscreens only work with a bare finger. Capacitive-powered touchscreens, for example, require physical contact with a conductive object, such as a bare finger. If you use a stylus, it won’t register or respond to your touch command. SAW touchscreens work with any object, however, including a stylus.