Measuring the Deformation of Adsorbed Particles using the Quartz Crystal Microbalance*

We numerically simulate the hydrodynamic force on ellipsoidal particles, adsorbed on an oscillating surface. From the simulation results, we fit a relation between this force and the particle aspect ratio and the oscillation frequency. The relation is used to extract shape information from quartz crystal microbalance (QCM) measurement data of the adsorption of 70 nm liposomes, whose shape is changed by varying the osmotic pressure difference across the liposomal bilayer. We thereby determine the membrane bending energy, consistent with literature values.