Deposition of coatings from live yeast cells and large particles by "convective-sedimentation" assembly.

Convective assembly at high volume fraction was used for the rapid deposition of uniform, close-packed coatings of Saccharomyces cerevisiae yeast cells onto glass slides. A computational model was developed to calculate the thickness profiles of such coatings for different set of conditions. Both the experiments and the numerical simulations demonstrated that the deposition process is strongly affected by the presence of sedimentation. The deposition device was inclined to increase the uniformity of the coatings by causing the cells to sediment toward the three-phase contact line. In accordance with the simulation, the experiments showed that both increasing the angle of the device and decreasing the angle between the slides increased the uniformity of the deposited coatings. Finally, the "convective-sedimentation" assembly method was used to deposit mixed layers of live cells and large latex particles as an example of immobilized biologically active composite coatings.