Identification particles and system and method for retrospective identification using spectral codes

Abstract

A system and method using reporter elements provides retrospective identification of articles. An article is marked with reporter elements such that the mark has a characteristic spectral response when exposed to energy stimulation. To verify the authenticity of the article, a reader scans the mark containing the reporter elements and obtains a spectral signature. The reader then compares the detected signature to the characteristic signature to determine the authenticity or identity of the marked article.

1 - 20 . (canceled)  
   
   
       21 . An identification system, comprising 
 a) a particle incorporating a code;    b) a carrier material entraining the particle; and    c) a reporter element incorporated into the entraining carrier material, said reporter element emitting a spectral signature responsive to energy stimulation.    
   
   
       22 . The system of  claim 21 , wherein the particle incorporates a sequence of colored layers, wherein the sequence of the colored layers provides the code.  
   
   
       23 . The system of  claim 21 , wherein the reporter element is phosphorescent.  
   
   
       24 . The system of  claim 21 , wherein the reporter element is fluorescent.  
   
   
       25 . The system of  claim 21 , wherein the reporter element is photochromic.  
   
   
       26 . The system of  claim 21 , wherein the reporter element is thermochromic.  
   
   
       27 . The system of  claim 21 , wherein the reporter element is an up-converting phosphorescent material.  
   
   
       28 . The system of  claim 21 , wherein the reporter element emits a spectral signature responsive to an infrared energy stimulation.  
   
   
       29 . The system of  claim 21 , wherein the reporter element is a semiconducting nanocrystal.  
   
   
       30 . The system of  claim 21 , wherein at least two reporter elements are incorporated into the entraining carrier material, said two reporter elements having a different spectral response to energy stimulation.  
   
   
       31 . A method of making a coded particle, comprising the steps of: 
 a) causing a coded particle to be entrained in a carrier material; and    b) causing a reporter element to be entrained in the carrier material.