How Surface Wave Acoustic Touchscreens Work

by | Sep 4, 2017

Not all touchscreen devices use capacitive or resistive touch-sensing technology. There are more than a dozen different technologies used to power touchscreen devices, including surface wave acoustic (SWA).

Also known as surface acoustic wave, SWA is an alternative touch-sensing technology that uses ultrasonic waves to identify when and where a touch occurs on the interface. In an SWA touchscreen device, there’s a component that emits an acoustic wave over the surface of the device’s interface. When the user touches the interface, he or she absorbs some of this ultrasonic acoustic wave. The device is able to identify the precise location of the user’s touch by looking for changes in the acoustic wave. The area at which point the acoustic wave was disturbed (absorbed) is identified by the controller.

Here’s another way of looking at SWA touchscreen technology: the device emits ultrasonic waves in a grid-like fashion across both axes of the interface. When you touch the interface, the wave is disturbed. Although you can’t see or feel the ultrasonic wave, it’s there — and the device uses this invisible wave to identify the point of touch.

Of course, there are several benefits associated with SWA touchscreens, one of which is superior image quality. When compared to conventional touchscreen configurations such as resistive and capacitive, SWA typically offers higher quality images with better resolution (4096 x 4096). Additionally, there are no underlying layers with SAW touchscreens. There’s a glass layer on top, but no other layers that can be worn down underneath. This means SWA touchscreens tend to last longer than their counterparts, and they are able to withstand countless hours of use without showing signs of age.

Furthermore, the SWA touchscreens offered by Nelson Miller can be used with or without a bare finger. As you may already know, capacitive touchscreen devices require the use of a bare finger. Since they identify touch by measuring change in capacitance, you can’t use a stylus with a capacitive touchscreen device; it only works with a bare finger or special capacitive stylus. SWA touchscreens, on the other hand, can be used with a bare finger, gloved finger or traditional stylus.

The bottom line is that SWA touchscreens deliver a high-quality image, durable and long-lasting construction, and they can be used with a bare finger or gloved finger. For these reasons and more, many companies are now choosing SWA over conventional capacitive and resistive touch-sensing technology.

Contact Us Today to See How We Can Assist You