By ADMetro In
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SAW Touch Screens

Comparison between Capacitive vs Surface Acoustic Wave (SAW) Touch Screens

With the widespread usage and demand of touch interface devices, the use of touch screens has evolved and grown significantly. Today, there are several different types of touch screen technologies for diverse operational environments, like military, industrial, retail, and gaming applications, etc. It is all about providing seamless performance through best-suited touch technologies. But what needs to be remembered is that not all touch screen technologies are the same. They all vary in construction and mode of operation.

We’ll look at two of them; surface capacitive and surface acoustic wave (SAW) touch screens which are two popular types of touch screens employed in touch applications. But there are some distinctive features of capacitive and SAW touch technologies that set them apart from each other.

Surface Capacitive Touch Screens
Surface Capacitive touchscreens are made of a transparent conductive layer on a glass substrate coated with a protective silicate layer. When a fingertip comes into contact with the interface, they use the conductivity of the human body as a means for input. The surface of the sensor is charged with a radio frequency. A touch creates a capacitive coupling that dissipates some of the radio frequency allowing the touch screen’s electronic interface to identify the location of the input command.

Benefits of Capacitive Touch Screens
Being the most popular (more than SAW touch screens technology), it is no surprise that capacitive touch screens offer myriad benefits. From optical clarity, high-quality image display to accuracy and light touch, all these qualities make capacitive touch screens the best choice for smartphones, ATMs, Kiosks, and more. Moreover, there’s an advanced version- projected capacitive touch screens that offer a much better experience compared to conventional surface capacitive and are more widely used.

SAW Touch Screen
As stated earlier, every touchscreen is based on a distinctive technology, Surface Acoustic Wave (SAW) touch screens use ultra-sonic waves to detect the touch input. On tapping or touching the display interface, the ultrasonic waves in that area are disturbed, allowing the touch screen’s electronic interface to detect the position of the touch command.

Benefits of SAW Touch Screens
Though SAW touch screens have never attained popularity of their capacitive counterpart, they offer many benefits making them worth using. Unlike capacitive touch screens that are limited to using a bare finger for input, SAW touch screens do not require a conductive object to register a touch. Unlike capacitive touch screens, SAW touch screens can be operated with any object that can absorb ultrasonic waves which includes things like heavily gloved hands.

Furthermore, both touch screens are durable and long-lasting as touch inputs put little or no stress on the display. Also, the faster response time of SAW touch sensors makes them a perfect choice for a number of applications. These are mostly used as interactive displays in gaming, public information kiosks, computer-based training and other high traffic indoor environments.

However, SAW touch screens are not recommended for outdoor environments as they can be affected by a large amount of dirt, dust, water droplets etc. Otherwise, they provide an attractive, simple to implement, and cost-effective solution for indoor applications.

If you find SAW touch screens a better choice, you find a reliable solution at A D Metro. They offer a complete line of Surface Acoustic Wave (SAW) touch screens, bundled with a controller with either a USB or RS232 interface.


Ask the touch screen experts at A D Metro