The SmartFinger^Ò technology developed by IDEX, SINTEF and ST Microelectronics reproduces the image of a finger based on an AC capacitive measurement method. This method involves using an excitation AC signal that propagates an electric field through the finger, and a capacitive sensor for detecting the fingerprint contours. The scheme detects the ridges and valleys in the living layer of skin beneath the skin surface and provides a straight, precise image of the ridges and valleys of the finger. The architecture integrates three functions: fingerprint, navigation and pointer detection. During the fingerprint detection mode the finger is swiped over the module, the fingerprint pattern is detected, and an image of the fingerprint is generated. In the navigation mode the swipe sensor is used for 4 directional navigation (up down and right-left). In the pointer mode the swipe sensor is used as a pointing device or mouse. If a user moves a finger across the sensor surface the velocity and the direction of the finger movement is calculated. This enables the user to move a cursor on a graphical display. In both navigation and pointer modes is possible to recognize a finger being tapped onto the sensor surface. Thus, single tapping and/or double tapping can be used for selecting objects and menus. The application areas for fingerprint detection systems are PC access, money transaction authorisation, car access, mainstream identification systems for network communication and mobile/cellular phones, Internet e-commerce, military installations, law enforcement and forensics applications.

For more information contact: Ovidiu Vermesan