When sweat comes in handy [Progress]

NEED A FOOLPROOF FINGERPRINT identification system? No sweat. Engineers at West Virginia University (Morgantown) and Avaya Labs (Basking Ridge, N.J.) have developed software that analyzes sweat patterns on fingertips and so prevents the use of synthetic or dismembered fingers–a subterfuge, seen in spy movies, that could also pose a problem in real life. Many fingerprint detectors rely on capacitive sensor arrays, which map the print by scanning and measuring the skin’s electrical characteristics. The new scheme takes such a sensor and programs it to detect changes in the finger's pattern of perspiration, which is highly conductive compared to dry skin.