Back to results
US 9,824,252 B1Granted
Chemical sensors based on chipless radio frequency identification (RFID) architectures
AssigneeXerox Corporation
InventorGeorge A. Gibson
Life of this patent
Estimating the term…
Abstract
A method and structure for a radio frequency identification (RFID) sensor that may be used to monitor various environmental conditions. The environmental condition measured depends on a sensor material used in the RFID sensor. The sensor material is selected based on a flux in electrical conductivity relative to its saturation of the environmental condition being monitored. The sensor material is placed between adjacent electrically conductive structures of the RFID sensor. Upon a change in the environmental condition being measure, the electrical conductivity of the sensor material changes, thereby increasing or decreasing an amplitude of a response by the RFID sensor to an interrogation by an RFID reader.
Claims18
A radio frequency identification (RFID) device, comprising:
- a receive antenna;
- a transmit antenna;
- a multiresonator comprising a plurality of resonators, wherein the multiresonator is electrically coupled between the receive antenna and the transmit antenna;
- and
- a sensor material bridging two or more electrically conductive structures of the RFID device, wherein:
- the sensor material has a variable electrical conductivity that is configured to change depending on an environmental condition to which the sensor material is exposed;
- a resonation amplitude of the multiresonator is configured to attenuate by a first amount dependent on a first electrical conductivity of the sensor material to provide a first response, and to output the first response having a first amplitude from the RFID sensor, wherein the first amplitude is dependent on a first state of the environmental condition;
- and
- the resonation amplitude of the multiresonator is configured to attenuate by a second amount dependent on a second electrical conductivity of the sensor material to provide a second response, and to output the second response having a second amplitude from the RFID sensor, wherein the second amplitude is dependent on a second state of the environmental condition.
6 more elements
A radio frequency identification (RFID) system, comprising:
- an RFID reader;
- and
- an RFID sensor device configured to receive an interrogation from the RFID reader and to output a response to the RFID reader upon receipt of the interrogation, wherein the RFID sensor device comprises:
- a receive antenna;
- a transmit antenna;
- a multiresonator comprising a plurality of resonators, wherein the multiresonator is electrically coupled between the receive antenna and the transmit antenna;
- and
- a sensor material bridging two or more electrically conductive structures of the RFID device, wherein:
- the sensor material has a variable electrical conductivity that is configured to change depending on an environmental condition to which the sensor material is exposed;
- a resonation amplitude of the multiresonator is configured to attenuate by a first amount dependent on a first electrical conductivity of the sensor material to provide a first response, and to output the first response having a first amplitude from the RFID sensor, wherein the first amplitude is dependent on a first state of the environmental condition;
- and
- the resonation amplitude of the multiresonator is configured to attenuate by a second amount dependent on a second electrical conductivity of the sensor material to provide a second response, and to output the second response having a second amplitude from the RFID sensor, wherein the second amplitude is dependent on a second state of the environmental condition.
9 more elements
A method for sensing an environmental condition, comprising:
- receiving a first interrogation from a radio frequency identification (RFID) reader using an RFID sensor, wherein the RFID sensor comprises:
- a receive antenna;
- a transmit antenna;
- a multiresonator comprising a plurality of resonators, a first arm of the multiresonator, and a second arm of the multiresonator spaced from the first arm by an interstitial space, wherein the multiresonator is electrically coupled between the receive antenna and the transmit antenna;
- and
- a sensor material within the interstitial space and bridging a width of the interstitial space between the first arm and the second arm, wherein the sensor material has a variable electrical conductivity that is configured to change depending on the environmental condition to which the sensor material is exposed;
- attenuating a resonation amplitude of the multiresonator by a first amount dependent on a first electrical conductivity of the sensor material to provide a first response;
- outputting the first response having a first amplitude from the RFID sensor, wherein the first amplitude is dependent on a first state of the environmental condition;
- receiving a second interrogation from the RFID reader using the RFID sensor;
- attenuating the resonation amplitude of the multiresonator by a second amount dependent on a second electrical conductivity of the sensor material to provide a second response, wherein the first amount is different than the second amount;
- and
- outputting the second response having a second amplitude from the RFID sensor, wherein the second amplitude is different from the first amplitude and is dependent on a second state of the environmental condition.
9 more elements
Dependencies are inferred from the claim text.