No abstract

A material-based bottom-up approach is proposed towards an assembly of cells and engineered micro-objects at the macroscale. We show how shape, size and wettability of engineered micro-objects play an important role in the behavior of cells on these objects. This approach can, among other applications, be used as a tool to engineer complex 3D tissues of clinically relevant size.

Currently, there is a great interest in the use of engineered complex slip surfaces as well as the surface texturing because these surfaces are able to improve the tribological performance of lubricated contacts. In this paper, based on the modified Reynolds equation, a systematic comparison is made with various surface conditions, that is, texturing, slip, and the combination of those configurations with respect to the performance of flat classical (no-slip) contact. Optimum values of design parameters (slip length, slip zone, texture cell aspect ratio, and texturing zone), allowing for maximum load support, are presented. In the case of combined texture/slip pattern, it is shown that the load support does not practically depend on the texture cell aspect ratio. The slip effect has a much higher contribution in inducing the pressure distribution than the texturing effect. It is also demonstrated that partial texturing gives a better improvement than full texturing. However, compared to a flat complex slip surface, a partially textured surface is still less efficient to enhance the load support, even if this textured configuration is combined with a slip condition.

No abstract

In this paper we report the experimental investigation to evaluate the published models for the contact of a deformable sphere against a hard flat in the fully plastic contact regime. A new measurement method has been used to measure the contact area. The behavior of the mean contact pressure and the contact area as a function of the contact load are presented. Substantial differences are found between the measurements and the model predictions. A constant value of the mean contact pressure as the load increases is observed, however, the value is lower than the hardness, as often reported. The contact area is found to be a simple truncation of the sphere by a hard flat.