Time dependent-temperature independent color changing label

Abstract

A timing device for indicating a passage of a duration of time is disclosed. The timing device in accordance with the embodiments of the invention has a grid array architecture. The grid array architecture includes an electrode structure with an anode layer, a cathode layer and a thermistor layer. The anode layer and the thermistor layer are electrically coupled through a plurality of cathode trace structures. In operation the timing device is actuated through a suitable mechanism to initiate depletion of the anode layer and, thereby, indicate a passage of a duration time. As the anode layer depletes, sequential cathode trace structures are exposed and the thermistor layer acts as a temperature dependent resistor through a plurality of exposed cathode trace structures.

1 - 26 . (canceled) 
     
     
         27 . A timing device comprising:
 a. an anode layer; and   b. a cathode structure electrically coupled to the anode layer and at a first end of the timing device,   wherein after activation, the anode layer uniformly depletes away from and perpendicular to the first end in order to indicate a passage of time.   
     
     
         28 . The timing device of  claim 28 , wherein the timing device comprises a plurality of cathode structures introduced throughout a length of the timing device. 
     
     
         29 . The timing device of  claim 28 , wherein the cathode structures are reintroduced throughout the timing device at evenly spaced intervals. 
     
     
         30 . The timing device of  claim 28 , wherein the cathode structures are reintroduced throughout the timing device at unevenly spaced intervals. 
     
     
         31 . The timing device of  claim 28 , wherein the cathode structures divide the anode layer into a plurality of cells, wherein an overall depletion time of the anode layer of the timing device is equal to a sum of a plurality of cell depletion times of the plurality of cells. 
     
     
         32 . The timing device of  claim 27 , wherein the timing device is configured to expire at a constant rate. 
     
     
         33 . The timing device of  claim 27 , wherein the timing device is configured such that there is an acceleration of the depletion of the timing device as the timing device nears expiration. 
     
     
         34 . A timing system comprising:
 a. an anode layer;   b. a first timing cell coupled to the anode layer and comprising a first cathode structure; and   c. a second timing cell coupled to the anode layer and comprising a second cathode structure,   wherein after activation, the anode layer is depleted in a direction away from the first cathode structure of the first timing cell and toward the second cathode structure of the second timing cell and wherein a total depletion of the first timing cell and the second timing cell indicate an elapsed time period.   
     
     
         35 . The timing system of  claim 34 , wherein the first timing cell and the second timing cell are configured to represent a same time period length. 
     
     
         36 . The timing system of  claim 34 , wherein the first timing cell and the second timing cell are configured to represent different time period lengths. 
     
     
         37 . The timing system of  claim 34 , wherein the cathode structures divide the anode layer into a plurality of cells, wherein an overall depletion time of the anode layer of the timing device is equal to a sum of a plurality of cell depletion times of the plurality of cells. 
     
     
         38 . The timing system of  claim 34 , wherein the first timing cell and the second timing cell are configured to expire at a constant rate. 
     
     
         39 . The timing system of  claim 34 , wherein the first timing cell and the second timing cell are configured such that there is an acceleration of the depletion of each timing cell as the timing device nears expiration. 
     
     
         40 . A method of manufacturing a timing device comprising:
 a. positioning a first cathode structure onto a length of the timing device;   b. positioning a second cathode structure onto a length of the timing device, wherein the first cathode structure is positioned to form a first timing zone along a length of the timing device and the second first cathode structure is positioned to form a second timing zone along a length of the timing device; and   c. depositing an anode layer onto the timing device.   
     
     
         41 . The method of  claim 40 , wherein the first timing cell and the second timing cell are configured to represent a same time period length. 
     
     
         42 . The method of  claim 40 , wherein the first timing cell and the second timing cell are configured to represent different time lengths. 
     
     
         43 . The method of  claim 40 , wherein the cathode structures divide the anode layer into a plurality of cells, wherein an overall depletion time of the anode layer of the timing device is equal to a sum of a plurality of cell depletion times of the plurality of cells. 
     
     
         44 . The method of  claim 40 , wherein the first timing cell and the second timing cell are configured to expire at a constant rate. 
     
     
         45 . The method of  claim 40 , wherein the first timing cell and the second timing cell are configured such that there is an acceleration of the depletion of each timing cell as the timing device nears expiration.