The principle of pressure sensing is that when a finger is placed over the sensor area, only the ridges of the fingerprint come in contact with the sensor piezo array. The valleys in contrast have no contact with the sensor cells. A main difference for the further recognition and matching to other sensors we have is pressure sensors generate a 1-bit binary image. A 1-bit image has less information than an 8-bit gray-scale image.

A surface pressure sensor can be considered as allowing clearly to sense both dry and wet fingers. Furthermore it has a large sensing area, which enables it to capture a complete fingerprint for better accuracy of recognition that leads to a lower EER (Equal Error Rate.)