SENSING EXPOSURE TO ENVIRONMENTAL FACTORS

• US 20140062654A1
• Filed: 08/31/2012
• Published: 03/06/2014
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Cok, Ronald Steven, White, Christopher J.
• Granted Patent: US 8,810,391 B2
• Time in Patent Office: Days
• US Class Current: 340/5.61
• CPC Class Codes: G06K 19/0717 the sensor being capable of sensing environmental conditions such as temperature history or pressure
• CPC Class Codes: G07C 3/00 Registering or indicating the condition or the working of machines or other apparatus, other than vehicles

Abstract

A method of sensing exposure to one or more of a plurality of environmental factors includes exposing a code circuit to at least some of the environmental factors, the code circuit disposed over a substrate and including a plurality of electrically-connected sensor patches, each sensor patch susceptible to one of the environmental factors, wherein the code circuit has an electrical state. An electrical excitation signal is passed through the code circuit, and a corresponding received electrical signal detected, using a transceiver formed on a transceiver substrate separate from and disposed over the substrate, wherein the transceiver includes a controller and the received electrical signal depends on the excitation signal and the electrical state of the code circuit. Using the controller, the received electrical signal or a representation thereof is automatically stored in a memory. The checking and storing steps are automatically repeated after one or more selected time intervals.

Claims

1. A method of sensing exposure to one or more of a plurality of environmental factors, comprising:

exposing a code circuit to at least some of the environmental factors, the code circuit disposed over a substrate and including a plurality of sensor patches, each sensor patch having a respective electrical state that changes with exposure to one of the environmental factors, so that the code circuit has an electrical state;

a checking step of passing an electrical excitation signal through the code circuit, and detecting a corresponding received electrical signal, using a transceiver formed on a transceiver substrate separate from and disposed over the substrate, wherein the transceiver includes a controller and the received electrical signal depends on the excitation signal and the electrical state of the code circuit;

using the controller, automatically storing the received electrical signal or a representation thereof in a memory; and

using the controller, automatically repeating the checking and storing steps after one or more selected time intervals.

2. The method according to claim 1, further including the controller receiving a downlink signal and, in response, transmitting an uplink signal representing the stored received electrical signal(s) or representation(s) thereof.

3. The method according to claim 1, wherein the checking step further includes the controller automatically comparing the received electrical signal with a selected criterion and, if the signal corresponds to the criterion, activating an actuator.

4. The method according to claim 3, wherein the actuator is adapted to dispense a drug when activated.

5. The method according to claim 4, wherein the actuator dispenses the drug into the gastrointestinal tract or circulatory system of a human or animal.

6. The method according to claim 1, wherein each of the sensor patches includes a respective electrically-conductive layer susceptible to the corresponding one of the environmental factors, so that each of the sensor patches changes electrical state when exposed to the corresponding one of the environmental factors.

7. The method according to claim 1, wherein a selected one of the sensor patches includes an electrically-conductive layer susceptible to the corresponding environmental factor, so that the selected sensor patch changes electrical state when exposed to the corresponding one of the environmental factors.

8. The method according to claim 1, wherein one of the sensor patches includes an electrically-insulating layer and a conductor arranged on a side of the electrically-insulating layer closer to the substrate, the electrically-insulating layer and the conductor susceptible to the corresponding environmental factor.

9. The method according to claim 1, wherein one of the sensor patches includes an electrically-insulating layer and a conductor arranged on a side of the electrically-insulating layer closer to the substrate, the electrically-insulating layer susceptible to the corresponding environmental factor and the conductor susceptible to a respective environmental factor different from the corresponding environmental factor of the electrically-insulating layer.

10. The method according to claim 1, wherein:

the exposing step includes contemporaneously exposing a plurality of code circuits to the at least some of the one or more environmental factors, each code circuit disposed over the substrate and including a respective plurality of electrically-connected sensor patches, each sensor patch having an electrical state that changes with exposure to a corresponding one of the one or more environmental factors, so that each code circuit has a respective electrical state;

the checking step includes passing a respective electrical excitation signal through each code circuit and detecting a respective received electrical signal; and

the storing step includes, using the controller, automatically storing the respective received electrical signals or respective representations thereof in the memory.

11. The method according to claim 10, wherein a first one of the code circuits includes respective sensor patches that are susceptible to a first subset of the plurality of environmental factors and a second one of the code circuits includes respective sensor patches that are susceptible to a second subset of the plurality of environmental factors different from the first subset.

12. The method according to claim 1, further including, before the exposing step, disposing the sensor patches of the code circuit over the substrate by depositing respective conductors and printing respective susceptible layers over the conductors, each susceptible layer susceptible to a corresponding one of the one or more environmental factors.

13. The method according to claim 1, wherein the sensor patches are arranged in a patch stack including a first-exposed one of the sensor patches and one or more buried ones of the sensor patches arranged between the first-exposed one of the sensor patches and the substrate, and the code circuit includes a seal lower in susceptibility to each of the respective environmental factors than the respective sensor patches in the patch stack, the seal arranged so that each of the buried sensor patches is permitted to be exposed to the respective environmental factor only through a void in one or more of the sensor patches farther from the substrate than that buried sensor patch.

14. The method according to claim 13, wherein:

the one or more buried ones of the sensor patches include a second-exposed sensor patch adjacent to the first-exposed sensor patch;

the seal and patch stack are arranged to define a cavity between them, the cavity sealed off from the environmental factors of the plurality of sensor patches by the seal and the first-exposed sensor patch;

the patch stack is arranged so that the second-exposed layer has a flow surface adjacent to the first-exposed layer, the flow surface having a shape, orientation, or composition that defines a flow pattern; and

the first-exposed sensor patch is made fluid by exposure to the corresponding environmental factor, so that when the first-exposed sensor patch becomes fluid, at least some of the resulting fluid travels substantially according to the flow pattern into the cavity to permit the second-exposed sensor patch to be exposed to the corresponding environmental factor.

15. The method according to claim 13, wherein the sensor patches are electrically connected in parallel.

16. The method according to claim 13, wherein the first-exposed sensor patch is susceptible to heat and has a selected thermal conductance greater than a thermal conductance of the seal.

17. The method according to claim 16, wherein the first-exposed sensor patch consists of an electrically-conductive material and zero or more inclusions that together do not reduce the conductivity of the electrically-conductive material by more than fifteen percent.

18. The method according to claim 81, wherein the sensor patches are distributed over the substrate so that they are exposed to an external environmental factor substantially contemporaneously.

19. The method according to claim 18, wherein the sensor patches are electrically connected in series.