Biometric sensors no dirtier than doorknobs, study finds

Researchers at Purdue's Biometric Standards, Performance and Assurance Laboratory test bacteria from a vein-recognition reader, a biometric device that can authenticate a person's identity. Researchers have found that although the... Click here for more information.

WEST LAFAYETTE, Ind. - While biometric equipment is gaining popularity in a variety of applications, such as ensuring secure access to buildings, industries are finding that many users believe the devices are unsanitary and a potential source of germs that could cause illness.

But a Purdue University study has found that while the platen glass surfaces of devices that scan fingerprints or hand geometry may look more unsanitary due to visible dirt and prints, they in fact harbor about the same amount of bacteria as a typical doorknob.

Christine R. Blomeke, a researcher and doctoral student in Purdue's Biometric Standards, Performance and Assurance Laboratory, performed the study along with lab director Stephen J. Elliott, an associate professor of industrial technology, and Thomas M. Walter, a continuing lecturer in the Department of Biological Sciences.

Blomeke said the study was conducted because of participant comments made during fingerprint and hand-geometry studies at the lab. She said the subjects, who were required to touch their hands or fingers to the sensors, questioned the cleanliness of the surfaces.

"When you look at these devices, finger moisture, dirt and oils cause the surface to appear to be dirty," Blomeke said. "In a study we did on this last year, more than a quarter of the participants indicated that they thought the devices were somewhat unsanitary.

"Since the use of biometric devices is rapidly expanding in public spaces, such as airports, stores and banks around the world, we felt it was important to examine whether touching these surfaces would subject users to more germs than they would be exposed to by touching objects such as pens, doorknobs and elevator buttons."

The results of the study were presented this week at the Institute of Electrical and Electronics Engineers International Carnahan Conference on Security Technology in Ottawa, Ontario, Canada.