PATCHES focused on a multi-scale hybrid computation/experimental study of the tribologically induced surface charge of different biocompatible materials when subjected to common mechanical contacts such as sliding and fracture. Mechanical contacts are, indeed, known to affect the distribution of the charge on the materials surface and the redistribution of charged groups at the interface between proteins and surface and this is a key factor in the adsorption of the proteins, thus of materials biocompatibility. The study was conducted using Density Functional Theory (DFT) calculations and Molecular Dynamics (MD) simulation methods and the computational models were validated by experimental tests.
Overall the project met the main objective of designing a multi-scale hybrid
computation/experimental method to analyse the surface charge of biocompatible materials for typical contact conditions. Specifically, this was achieved through two main objectives: i) simulating the charge density of different bio-materials, such as diamond, amorphous silica and diamond-like-carbon (DLC) as subjected to sliding and fracture and comparing the results with experimental measurements; ii) using the evaluated charge distribution to study how it affects the adsorption of saliva proteins onto the surface of the set of biomaterials considered.
The results obtained from the analysis of the amorphous silica and the PTFE bulk at high pressure phase are one of the kinds. In fact, the amorphous silica results were obtained after a long computational calculation time, over a year, a study which was never done before and unlikely to be repeated. The PTFE structural values, instead, are a fundamental source for the scientific community because they will be the starting point for the modelling of a material to be used in a wide range of studies. Moreover, because of its unique properties PTFE is a major material for various other applications, in particular for green energy nanogenerators, which are devices that convert mechanical energy into electricity, and they are used for the development of smart cities. Therefore, the results of this study can also be exploited for environment climate challenges.
