Patent ID: 9546912
Date: 2017-01-17
CPC Classifications: G01K

Claim:
1. A time-temperature indicator (TTI) comprising: a substrate; a mesh layer affixed to the substrate; a photonic crystal patterned film affixed to the mesh layer and comprising a photonic crystal material, wherein the photonic crystal shows a property of bandgap shift vs temperature and thereby responds to a predetermined range of temperatures to provide a visible indication of the range of temperatures, the mesh layer with the photonic crystal material rendering a visual summary of a product's accumulated chill chain history, recording the effects of both time and temperature using pre-set times, and wherein the photonic crystal pattern provides a temperature recording medium with lattice spacing of the photonic crystal pattern, the lattice spacing controlling at least one characteristic of the time and temperature indication by the photonic crystal; and a hardener pouch containing a hardener and affixed to one end of the mesh layer and configured to allow release of the hardener in response to an initiating event, so as to dispense the hardener progressively across the patterned film as a function of time, modulated by temperature, progressively recording temperature across the patterned film as a function of time, thereby to provide continuous temperature recording in a designated relative time range to render the visual summary of the product's accumulated chill chain history, wherein the photonic crystal material responds to the hardener by presenting a fixed state.