Chipless RFID-based temperature threshold sensor

• US 10,739,211 B2
• Filed: 12/15/2017
• Issued: 08/11/2020
• Est. Priority Date: 12/16/2016
• Status: Active Grant

• Current Assignee: VDW Design, LLC
• Original Assignee: VDW Design, LLC
• Inventors: van der Weide, Daniel W., Martinez, Marcos
• Primary Examiner(s): Nguyen, Nam V
• Application Number:
  US15/843,894
• Publication Number:
  US 20180180491A1
• Time in Patent Office: 970 Days
• Field of Search: 340 101- 105
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01K 3/04 in respect of time
• CPC Class Codes: G01K 7/32 using change of resonant frequency of a crystal
• CPC Class Codes: G01K 7/343 the dielectric constant of which is temperature dependant
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications

Abstract

Provided herein are chipless radio-frequency identification (RFID)-based sensors that exhibit an altered electromagnetic signature when sensor-specific temperature threshold is crossed.

Claims

1. A chipless radio-frequency identification (RFID)-based sensor comprising a dielectric substrate material, one or more conductive resonators, and a temperature-sensitive superstrate material having a defined melting temperature;

wherein;

(a) if the RFID-based sensor is maintained at a temperature below the melting temperature of the temperature-sensitive superstrate material, then upon interrogation by an electromagnetic wave (EMW), the RFID-based sensor reflects a first electromagnetic signature (EMS); and

(b) if the RFID-based sensor is exposed to a temperature above the melting temperature of the temperature-sensitive superstrate material, then upon interrogation by the EMW, the RFID-based sensor reflects a distinguishable EMS, wherein the distinguishable EMS is detectably distinct from the first EMS;

wherein, if the RFID-based sensor has been exposed to the temperature above the melting temperature of the temperature-sensitive superstrate material, then the RFID-based sensor will not reflect the first EMS upon interrogation by the EMW even if the temperature at the time of interrogation has returned to a temperature below the melting temperature of the temperature-sensitive superstrate material.

2. The RFID-based sensor of claim 1, wherein the temperature-sensitive superstrate material comprises an aqueous solution.

3. The RFID-based sensor of claim 2, wherein the aqueous solution comprises sodium chloride (NaCl) in water (H₂O).

4. The RFID-based sensor of claim 1, wherein the conductive resonator is a slot resonator.

5. The RFID-based sensor of claim 1, wherein the conductive resonator is a microstrip resonator.

6. The RFID-based sensor of claim 5, wherein the microstrip resonator is in a staircase pattern.

7. The RFID-based sensor of claim 1, wherein the temperature-sensitive superstrate material comprises an organic solvent.

8. The RFID-based sensor of claim 1, wherein the organic solvent is selected from the group consisting of ethanol (EtOH), methanol (MEOH), acetic acid, tetrahydrofuran (THF), acetone, dioxane, and benzene.

9. The RFID-based sensor of claim 1, wherein the melting temperature is between 0°

C. and −

20°

C.

10. The RFID-based sensor of claim 1, wherein the melting temperature is between 1°

C. and 10°

C.

11. The RFID-based sensor of claim 1, wherein the dielectric substrate material, the one or more conductive resonators, and the temperature-sensitive superstrate material are contained within a protective polymer material.