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Amontons-Coulomb-like slip dynamics in acousto-microfluidics



Aurore F. Quelennec, Jason J. Gorman, Darwin Reyes-Hernandez


Electroacoustic technologies, which employ acoustic waves to manipulate and detect bioparticles, have been increasingly used, with a great deal of success, in life sciences. Particle manipulation or measurement capabilities of surface acoustic wave-based devices depend on the amount of acoustic energy transmitted from the vibrating crystal to the fluid. The acoustic energy transmitted to the fluid can be severely affected in the presence of slip at the fluid-crystal interface. However, the slip at the boundary is commonly neglected. We found that the slip depends on not only the density and the viscosity of the fluid but also the pressure and the shear stress from the flow. Our results show that the slip dynamics are Coulomb-like, such that with an increase in pressure, the shear stress must increase so that the fluid continues sliding. The occurrence of slip from the pressure-shear stress conditions could cause anomalous results in surface acoustic wave-based devices. Our findings demonstrate that the natural variance in density and viscosity of biofluids tested by these devices could vary the amplitude of slip. Therefore the outcome of these devices can drastically deviate from the expected results. A better understanding of this phenomenon can open the door for the design and development of reliable and accurate acousto-microfluidic technologies to bring about innovations in biology and medicine.
Nature Communications


surface acoustic waves, microfluidics, acousto-microfluidics, viscosity, slip, bioparticles, Coulomb


Quelennec, A. , Gorman, J. and Reyes-Hernandez, D. (2022), Amontons-Coulomb-like slip dynamics in acousto-microfluidics, Nature Communications, [online], (Accessed June 22, 2024)


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Created March 22, 2022, Updated June 16, 2022