Temperature sensitivity of capillary-driven flow: Application to age monitoring devices

The effects of time-dependent temperature fluctuations on surface-tension driven fluid flow inside a capillary are modeled using classical hydrodynamics. To begin, Newton’s second law is evoked to derive a nondimensional equation of motion that describes the time-evolution of the fluid front position and velocity as a function of system geometry, fluid properties, and fluid temperature. This model is used to examine how temperature excursions affect the instantaneous and long-term position and velocity of the fluid front inside the capillary. Next, the effects of orientation on the movement of high viscosity fluids through a capillary are examined. From these findings, a procedure is developed for designing non-powered time–temperature integration devices for recording the cumulative temperature exposure history of an environment.

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► We develop a model for predicting fluid movement through a capillary.
► We quantify the effects of temperature and orientation on the velocity of the fluid.
► The movement of the fluid can be linked to the Arrhenius relationship.
► It is easy to design a device for recording the long-term local temperature history.