ONE-TIME SENSOR DEVICE
First Claim
1. A one-time sensor assembly operable for sensing a predetermined condition, said sensor assembly comprising:
- a sensor unit including;
an elongated, resilient sensor element;
a support for said sensor element;
structure releasably holding said sensor element in a first configuration on said support,said sensor element operable to assume a second configuration different than said first configuration when said condition occurs; and
a detector separate from said sensor element and including a transmitter unit operable to transmit interrogating electromagnetic radiation to said sensor element,said sensor element having a first response to said radiation when the sensor element is in said first configuration, and a second response different from said first response when the sensor element is in said second configuration,said detector operable to detect the difference between said first and second responses.
1 Assignment
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Accused Products
Abstract
One-time, single-use sensor elements (22, 46) are provided for detecting the occurrence of predetermined conditions such as temperature and elapsed time-temperature. The sensor elements (22, 46) preferably comprise elongated, glass-coated, metal alloy, amorphous or nanocrystalline microwires (30, 48), which can be placed in a position to detect the predetermined condition of interest. An alternating magnetic field detector (28) may be used to continuously or periodically interrogate the sensor elements (22, 46) to determine if the predetermined condition has occurred. In one aspect of the invention, the microwires (30, 48) experience a change in configuration upon the occurrence of the predetermined condition, and have correspondingly different induced remagnetization responses. In another embodiment, a static microwire is provided having an initial bi-stable single domain; when a predetermined time-temperature condition is experienced, multiple domains are established in the microwire, and this can be detected by the detector (28).
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Citations
15 Claims
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1. A one-time sensor assembly operable for sensing a predetermined condition, said sensor assembly comprising:
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a sensor unit including; an elongated, resilient sensor element; a support for said sensor element; structure releasably holding said sensor element in a first configuration on said support, said sensor element operable to assume a second configuration different than said first configuration when said condition occurs; and a detector separate from said sensor element and including a transmitter unit operable to transmit interrogating electromagnetic radiation to said sensor element, said sensor element having a first response to said radiation when the sensor element is in said first configuration, and a second response different from said first response when the sensor element is in said second configuration, said detector operable to detect the difference between said first and second responses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of detecting the occurrence of a predetermined condition, comprising the steps of:
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placing a sensor unit in a position to sense said predetermined condition, said sensor unit including; an elongated, resilient sensor element; a support for said sensor element; structure releasably holding said sensor element in a first configuration on said support, said sensor element operable to assume a second configuration different than said first configuration when said condition occurs; and interrogating said sensor element by transmitting interrogating electromagnetic radiation to said sensor element, said sensor element having a first response to said radiation when the sensor element is in said first configuration, and a second response different from said first response when the sensor element is in said second configuration, detecting said second response as an indication of occurrence of said predetermined condition. - View Dependent Claims (10)
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- 11. A one-time sensor element operable to sense a predetermined time-temperature condition, said sensor element comprising an elongated, amorphous or nanocrystalline metal alloy sensor microwire having a positive magnetostriction property, and a bi-stable single magnetic domain aligned along the length of the microwire which can exist at any given time in one of two stable magnetic states, said sensor microwire operable to lose its bi-stable single magnetic domain and have a plurality of magnetic domains oriented generally circumferentially along the length of the sensor microwire, when the sensor microwire experiences said predetermined time-temperature condition.
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13. A method of detecting a predetermined time-temperature condition, comprising the steps of:
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placing a sensor element in a position to sense said predetermined time-temperature condition, said sensor element comprising an elongated, amorphous or nanocrystalline metal alloy sensor microwire having a positive magnetostriction property, and a bi-stable single magnetic domain aligned along the length of the microwire which can exist at any given time in one of two stable magnetic states, said sensor microwire operable to lose its bi-stable single magnetic domain and have a plurality of magnetic domains oriented generally circumferentially along the length of the sensor microwire, when the sensor microwire experiences said predetermined time-temperature condition; and interrogating said sensor element by creating an alternating magnetic field of sufficient magnitude to magnetically couple with said sensor element and induce a response from the sensor element, said sensor element exhibiting a remagnetization response prior to experiencing said predetermined time-temperature condition, and failing to exhibit a remagnetization response after experiencing said predetermined time-temperature condition. - View Dependent Claims (14, 15)
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Specification