Skin Properties

Skin properties can be used to recognize persons:

Skin spectrum / Spectre de la peau

Lumidigm has established that the absorption spectrum of the skin depends on the individuals.

Lumidigm a découvert que le spectre d'absorption de la peau est dépendant des individus.

Lumidigm sensor

Several LEDs send light at different wavelenghts into the skin, and photodiodes read the scattered light, which is analyzed to perform the authentication.

Plusieurs DELs envoient de la lumière de différentes couleurs dans la peau, et des photodiodes lisent la lumière diffusées, qui est ensuite analysée pour effectuer la reconnaissance.

Lumidigm sensor

Bio-Dynamic signature
Signature Bio-Dynamique

(2005 June) Idesia unveils the BDS500: a reader where you [gently place any two fingers from both hands, one on each contact sensor for just a few seconds. IDesia scientists have discovered a novel, natural Bio-Dynamic Signature ( BDS ) in humans - an electro bio signature that is unique to each individual and can be used to accurately identify any one person from all others.
Unlike most biometric technologies, which use pictures or static bio-signals to enroll and identify a person, BDS is based on intrinsic electro-biometric dynamic signals acquired by merely touching a small conductive or metal surface.] [copied from their website]
Well, I think they are mainly making an electrocardiogram, it is likely the most important signal they can read using such a method.

(2005 June) Idesia dévoile le BDS500: un lecteur où vous placez 2 doigts, un de chaque main, sur chacun des contacts pendant quelques secondes. Ils l'appellent la "signature bio-dynamique".
Je pense qu'ils font essentiellement un électrocardiogramme, c'est probablement les signaux du coeur qui sont le principal composant de l'information lue de cette manière.

Idesia BDS500