US 12,352,717 B2
Capacitance-based humidity and gas sensing RFID tags
Brian S. Huffman, Belle Mead, NJ (US); Deniz Boyu, Dover, NJ (US); Thi N. Do, West Orange, NJ (US); and Mohannad Abdo, Clifton, NJ (US)
Assigned to ZEBRA TECHNOLOGIES CORPORATION, Lincolnshire, IL (US)
Filed by Temptime Corporation, Morris Plains, NJ (US)
Filed on Jul. 18, 2022, as Appl. No. 17/867,031.
Prior Publication US 2024/0027385 A1, Jan. 25, 2024
Int. Cl. G01N 27/22 (2006.01); A61B 90/98 (2016.01)
CPC G01N 27/223 (2013.01) [G01N 27/221 (2013.01); G01N 27/228 (2013.01); A61B 90/98 (2016.02); G01N 2027/222 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An RFID tag system comprising:
an antenna;
an integrated circuit electrically connected to the antenna; and
a humidity and gas indicator being electrically connected to the antenna and the integrated circuit;
wherein the humidity and gas indicator comprises:
a first electrode;
a second electrode;
a dielectric material configured to have a first change in a dielectric constant of the dielectric material responsive to an exposure to humidity and to have a second change in the dielectric constant responsive to an exposure to a gas; and
a gap between the first electrode and the second electrode, at least a portion of the gap containing the dielectric material,
wherein the first change in the dielectric constant of the dielectric material causes a capacitance between the first electrode and the second electrode to change to a capacitance in a first predetermined range, and the second change in the dielectric constant of the dielectric material causes the capacitance between the first electrode and the second electrode to change to a capacitance in a second predetermined range,
wherein the integrated circuit is configured to indicate a presence of humidity when the capacitance between the first electrode and the second electrode is in the first predetermined range and configured to indicate a presence of the gas when the capacitance between the first electrode and the second electrode is in the second predetermined range.