This patent from IBM teaches a system using luminescent semiconductor nanoparticles (i.e. nanocrystals or quantum dots) in biometrics. Claim 1 reads:
1. An identity verification system comprising:
a combination of indicia that represents measurable characteristics mapped into a characteristic signature, wherein the measurable characteristics comprise a luminescent characteristic and a biometric characteristic, wherein the biometric characteristic is integrated with the luminescent characteristic to create a unique verification image; and
an indicia detector for detecting the characteristic signature and verifying authenticity of the characteristic signature, wherein the combination of indicia comprises colloidal nanoparticles having a characteristic emission spectrum comprising a plurality of lines at characteristic wavelengths with characteristic intensity ratio, wherein the indicia detector detects the characteristic emission spectrum.
Some prior art not cited during the patent prosecution but which may be relevant to the claims of this patent include:US Patent 6617583
- "A novel encoding system and methods for determining the location and/or identity of a particular item or component of interest is provided. In particular, the present invention utilizes a "barcode" comprising one or more sizes of semiconductor nanocrystals (quantum dots) having characteristic spectral emissions, to either "track" the location of a particular item of interest or to identify a particular item of interest. " (from abstract)US Patent 6633370
-"Quantum dots, semiconductor nanocrystals and semiconductor particles used as fluorescent coding elements" (title)US Patent 7077329
- "Spectral coding by fluorescent semiconductor nanocrystals for document identification and security applications" (title)