Touchscreen devices have been around for decades. Thanks to new advancements in touch-sensing technology, however, smartphones, tablets, human machine interfaces (HMIs) and other touchscreen devices are now more functional than ever. Used in both personal and commercial applications, they allow users to control a device by touching the display. It’s an easier and more convenient way to control devices than using a keyboard, mouse or other input peripherals.
Of course, there are different types of touch-sensing technology used to power touchscreen devices, the most common of which include resistive and capacitive. Resistive touchscreen devices identify touch by pressure. Touching the surface forces the upper layer to press against an underlying layer. The point at which these two layers make contact is thereby used to identify the location of the user’s touch. In comparison, capacitive touchscreen devices identify touch by measuring and looking for a change in capacitance.
A third type of touch-sensing technology that’s slowing gaining momentum in the touchscreen device market is Surface Acoustic Wave (SAW). It’s one of the latest types of touch sensing-technology, though more and more devices are now using.
What Is SAW Touch-Sensing Technology?
SAW is a new type of touch-sensing technology that identifies touch commands using ultrasonic waves. Invisible to the naked eye, SAW devices project ultrasonic waves across the surface of the display and touchscreen interface. When you touch the surface of this interface, it disturbs the otherwise uniform ultrasonic waves. Technically, your finger — or a stylus — absorbs some of the device’s ultrasonic waves. As the waves are absorbed, the device is cable to pinpoint the location of your touch by determining where the ultrasonic wave is missing or weak.
Benefits of SAW
Although it’s still new, many device manufacturers are now using SAW in their touchscreen devices — and for good reason. It offers several key benefits that shouldn’t be ignored. First, SAW touchscreen devices provide superior image quality. The display is clear, detailed and contains high resolution. For applications where display quality is essential, SAW is the perfect choice. Second, SAW touchscreen devices are highly responsive. It’s not uncommon for a SAW device to “respond” to the user’s touch command within 20 ms, meaning there’s no noticeable lag or delay from when you touch the device to when it responds with the appropriate action. Finally, SAW touchscreen devices can be used with a bare finger, a gloved finger or a stylus. This is in stark contrast to capacitive touchscreen devices, which only work with a bare finger or special capacitive stylus.
