Stimulus indicating device employing polymer gels

摘要

The present invention relates, for example, to a stimulus-indicating device. More particularly, the present invention includes an apparatus for evidencing when a stimulus sensitive product has been exposed to a designated or predetermined stimulus for a certain period of time, and the invention further may include a method for manufacturing aspects of that apparatus.

主权项

1. A stimulus indicating device that is capable of providing an irreversible indication of exposure to a predetermined stimulus comprising:
a first compartment; a stimulus sensitive gel contained inside said first compartment that has a chemical composition such that said stimulus sensitive gel permanently contracts from a first volume to a second volume in response to exposure to the predetermined stimulus regardless of whether the predetermined stimulus is removed; an indicator spot positioned inside said first compartment and that is positioned below said stimulus sensitive gel and that is physically covered by and is visibly blocked by said stimulus sensitive gel prior to exposure to the predetermined stimulus; an indicator window integral with said first compartment and that is positioned above said stimulus sensitive gel, and that is positioned above said indicator spot, for viewing into said first compartment; and wherein said stimulus sensitive gel has a chemical composition of poly(AAm-co-SB) gel.