Researchers at NIST have discovered that acoustic waves used to measure properties of fluids like blood can be affected by a phenomenon called “acoustic slip.” This slip occurs when the fluid surface moves slightly against the container wall due to the periodic motion of the acoustic waves.
The discovery is important because it can affect the accuracy of measurements in microfluids, including viscosity and blood cell sorting. If not accounted for, the change in acoustic wave absorption would be misinterpreted as changes in the fluid’s physical properties.
The researchers found that acoustic slip behaves similarly to friction between two solids, governed by the Amontons-Coulomb friction laws. By recognizing and accounting for this slip, researchers can achieve more accurate measurements in microfluids, which has implications for blood cancer diagnosis and blood cell sorting applications.
The findings were published in the March 22 issue of Nature Communications.
Keywords: Acoustic, Microfluid, Viscosity
