Capacitance-based temperature sensor with delay
AssigneeZebra Technologies Corporation
InventorsEric W. Liberato, Mohannad Abdo
Life of this patent
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Abstract
A temperature exposure indicator includes a first temperature responsive material, a capacitor including a first electrode, a second electrode, and a gap between the first electrode and the second electrode, and a first path connecting the first temperature responsive material to the gap. The first temperature responsive material is configured to migrate along the first path and into or along the gap in response to exposure to a temperature above a first threshold temperature. The migration of the first temperature responsive material into or along the gap causes a change of the capacitance of the capacitor.
Claims26
A temperature indicator comprising:
- a first temperature responsive material;
- a second temperature responsive material;
- a capacitor comprising:
- a first electrode,
- a second electrode, and
- a gap between the first electrode and the second electrode;
- a first path connecting the first temperature responsive material to the gap;
- and
- a second path connecting the second temperature responsive material to the gap,
- wherein the first temperature responsive material is configured to migrate along the first path and into or along the gap in response to exposure to a temperature above a first threshold temperature, the migration of the first temperature responsive material into or along the gap causing a first change of a capacitance of the capacitor, and wherein the second temperature responsive material is configured to migrate along the second path and into or along the gap in response to exposure to a second temperature above a second threshold temperature, the migration of the second temperature responsive material into or along the gap causing a second change of the capacitance of the capacitor, the capacitance of the capacitor after the the second change being different from the capacitance of the capacitor after the first change.
A temperature indicator comprising:
- a first temperature responsive material;
- a second temperature responsive material;
- a capacitor comprising:
- a first electrode,
- a second electrode, and
- a gap between the first electrode and the second electrode;
- a first path;
- and
- a second path,
- wherein the first temperature responsive material is configured to migrate along the first path and away from the gap in response to exposure to a temperature above a first threshold temperature, the migration of the first temperature responsive material away from the gap causing a first change of a capacitance of the capacitor, and wherein the second temperature responsive material is configured to migrate along the second path and away from the gap in response to exposure to a temperature above a second threshold temperature, the migration of the second temperature responsive material causing a second change of the capacitance of the capacitor, different than the first change.
Dependencies are inferred from the claim text.