Surface Acoustic Wave (SAW) touch technology is slowly being replaced by other touch technologies. While SAW differs from both projected capacitive and surface capacitive in its ability to be activated by different touch inputs, it’s harder to integrate. Durability also is a concern due to the sautered components.
How Surface Acoustic Wave (SAW) Works:
SAW touchscreens rely upon sound waves; thus, “sound wave reflectors” are placed along the edges of the glass. Two transducers are placed in two of the corners, and two receivers are mounted in the opposite corners. A sound wave travels parallel to the edges of the glass. When the sound wave encounters the reflectors, the wave is transmitted from the transducers to the receivers. A touch point is detected when a drop in the amplitude of the sound wave occurs.