Piezo-electric film as a sensor element in signature verification

The fraud protection currently provided by the personal identification number (PIN) is not always sufficient. Automatic verification of signatures at points of sale or bank terminals can improve this protection. Dynamic characteristics involved in writing a signature are difficult to forge but usually require specially wired pens, not suitable for hard day-to-day use. A low-cost piezoelectric film underneath a writing surface can detect stylus position and velocity profiles, thus permitting verification of the signature using both static and dynamic features. Arrays or parallel electrodes detect pen velocity profiles without being affected by touching fingers or by noise