Computational Optimization of the Orbital Shaker Operational Parameters in Endothelial Mechanobiology

Orbital shakers are used in endothelial (EC) mechanobiology to simulate hemodynamic environments, yet guidelines for selecting physiologically relevant parameters are lacking.

Using computational fluid dynamics (CFD) simulations, we investigated the effects of different orbital radii (A, at either 5 or 10 mm), angular velocities (RPM), and initial fluid heights (h₀) on wall shear stress (WSS) and free surface height (h) in 6-well plates on an orbital shaker.

We identified operational bounds that generate undisturbed flow (UF) at the periphery and disturbed flow (DF) at the center, with WSS levels analogous to those in human arteries (peripheral: 10-14 dynes/cm²; central: 3-6 dynes/cm²), while minimizing media spillage and transient air exposure. For A = 5 mm, recommended settings span 190-210 RPM across h₀ = 2.6-4.1 mm; for A = 10 mm, 170 RPM is suitable for h₀ = 2.6-4.1 mm. Peripheral WSS was relatively insensitive to h₀, while central WSS increased with decreasing h₀. Free surface analysis confirmed that maximum fluid height remained below the well rim under recommended conditions.

These insights inform orbital shaker settings that balance biological relevance with experimental practicality for EC mechanobiology studies.