The fingerprint sensors can be soiled by user’s fingers, dust, or other sources. This contamination may affect image quality, degrading authentication performance. The dust may be hard enough to make scratches on sensor surfaces. Scratches on optical sensors may be acceptable, but semiconductor sensors such as TC, FC and FL sensors may be damaged as user puts his/her finger on dust contaminated surface. One could be concerned about latent fingerprint images, although the latent images may not be used directly to deceive the fingerprint authentication system.
As the sensor physics differ from sensor to sensor, different method for cleaning should be applied.
If the installation site is dusty environment, and there is significant dust accumulated on the sensor surface, it is recommended to blow on the sensor before cleaning the sensor, to avoid abrasion. This applies to all types of sensors.
Optical sensors (OP, OC)
Gently wipe the sensor surface with a cloth dampened with warm water.
Do not submerge the sensor or pour liquid on the sensor. Avoid using abrasive material - including papers - while cleaning.
UPEK TouchChip (TC1, TC2)
Gently wipe the sensor with soft cloth.
NOTE: As the sensor is self cleaning type as the user swipes the finger, there is no need to clean the sensor in most cases.
Authentec AF-S2 (FL)
Gently rub the sensor surface and finger drive ring with partially wet cotton swab with window cleaner, such as Windex™.
After cleaning with the wet swab, rub the surface again with another dry cotton swab.
CAUTION \\Be sure not to make cleaner to drip or run down around the sensor.