Surface Acoustic Wave (SAW) vs Capacitive Touchscreens
Whether it's a smartphone, tablet or human machine interface (HMI), all touchscreen devices offer an unparalleled level of convenience. Rather than using a keyboard, mouse or physical buttons to control them, you can use your finger. All touchscreen devices support finger touches and taps to perform input commands. There are different types of touchscreen devices, however, including surface acoustic wave (SAW) and capacitive.
What Is SAW Touchscreen Technology?
SAW is a relatively new type of touchscreen technology that involves the use of ultrasonic sound waves to detect touch commands. When turned on, a SAW touchscreen device will project ultrasonic sound waves across the surface. As a result, touching or tapping the display interface will disrupt the ultrasonic sound waves in the area of your touch.
SAW touchscreen devices are equipped with sensors embedded around the perimeter to measure the ultrasonic sound waves. The touchscreen controller identifies the user's touch command by looking for blockages in the ultrasonic sound waves. From the controller, the electrical signals are passed to the transmitting transducer where they are converted into ultrasonic sound waves.
What Is Capacitive Touchscreen Technology?
Capacitive touchscreen technology, on the other hand, detects touch commands by measuring capacitance. More specifically, capacitive touchscreen devices look for a change in capacitance to determine where and when a touch command occurred.
Capacitive touchscreens emit a uniform electrostatic field across the surface of the uppermost and outermost layer. When you tap or touch your finger on a capacitive touchscreen device, your finger will draw some of the electrostatic charge towards it. The capacitive touchscreen device can then pinpoint your touch command based on the change of capacitance.
