Based on the hydrodynamic film thickness measured at different speeds as shown in Fig. 2, the shear rate of the lubricating film at the slider surface can be calculated according to the hydrodynamic lubrication theory. The shear rates along the slider surface at two speeds ud of 7.92 and 21.27 mm/s and load of 4 N are shown in Fig. 13. In the outlet zone, Couette and Poiseuille flows were in the same direction. Therefore, the film shear rate was the highest (104 s−1). High shear rate could change the conformation of the proteins and enhance adsorption, but it could also reduce adsorption rate brought about by mechanical action. Hence, increase in shear rate had both positive and negative effects on protein adsorption. Previous studies of the shear effect on protein adsorption were conducted by controlling the fluid transportation [24], [25] and [26]. Shear rates or shear stresses could have different influences on protein adsorption depending on the working conditions. For example, Uyen et al. [24] reported that the amount of adsorbed bovine serum albumin increased with increasing shear rates for low bulk concentrations, but it was opposite when the concentration was high. Nevertheless, results from this study, as illustrated in Fig. 12, show the formation of thicker adsorption film under faster operating speeds, at which shear rate was higher compared with those under lower speeds, particularly in the outlet region, as shown in Fig. 13. The present experiments demonstrate that high shear rate promotes protein adsorption.