Low yield stress measurements with a microfluidic rheometer.

Yield stress, , is a key rheological property of complex materials such as gels, dense suspensions, and dense emulsions. While there is a range of established techniques to measure in the order of tens to thousands of pascals, the measurement of low , specifically below 1 Pa, remains underexplored. In this article, we present the measurement of low apparent using a Hele-Shaw microfluidic extensional flow device (MEFD).

The yielding behaviour of human mucus.

Mucus is a viscoelastic material with non-linear rheological properties such as a yield stress of the order of a few hundreds of millipascals to a few tens of pascals, due to a complex network of mucins in water along with non-mucin proteins, DNA and cell debris. In this review, we discuss the origin of the yield stress in human mucus, the changes in the rheology of mucus with the occurrence of diseases, and possible clinical applications in disease detection as well as cure. We delve into the domain of mucus rheology, examining both macro- and microrheology.