The nature of interface in contact with skin, clothes or joints is one of the prime interests in the field of metallic biosensors. This interface can be enhanced through PVD processes in terms of chemistry and microstructure. Furthermore, dynamic evaluation of the contact interface at the early stage is essential to better understand the wear mechanism and to anticipate the efficient service life of the corresponding bio-device. Therefore, within this thesis, a laboratory-made micro-tribometer was developed and presented. This particular reciprocating ball-on-disk stage is coupled with an environmental SEM (eSEM) to characterise, at small scale, the tribological behaviour of the system under realistic in situ conditions. To express the proof of concept, a preliminary analysis was performed with a conventional TiN PVD hard coatings, used as a model surface. The testing procedure for the dynamic approach during the run-in period throughout 100 cycles was defined in the controlled atmosphere in eSEM chamber (both in high vacuum and 50% relative humidity (RH)). When the tribological tests were performed, the wear track of the films was examined in situ after every 10 cycles, while the ball track was analysed in post mortem mode. Once validated, the mini-tribometer stage was applied for a more realistic metal used in biosensor systems: titanium. Indeed, this metal presents a high biocompatible character, coupled with interesting mechanical properties. The wear character of pure Ti film is still an issue, due to its columnar microstructure, which can be modified with an addition of proper alloying elements. In this sense, silver is an outstanding material to be alloyed with titanium for bio-sensor applications regarding its anti-bacterial character and ductile nature, as well its remarkable sliding behaviour in nanoparticle form. Within this thesis, Ti-Ag films were deposited with magnetron sputtering PVD process with several Ag contents. Various types of multiscale characterization (microstructural, chemical, electrical, mechanical) were performed to analyse the effect of Ag in the film composition. It was shown that increasing Ag content led to a denser microstructure with Ag-based nano-/micro-meter sized clusters distributed into the film matrix. Moreover, from a functional point of view, it also provided a slight improvement on hardness, Young’s modulus and electrical conductivity of the films. During the in situ tribological analysis, the small-scale strategy of characterization that was specifically developed in this PhD, has highlighted a strong influence of the contact environment on its tribological behaviour. In particular, the effect of the humidity rate of the contact region on the tribological behaviour was deeply investigated, and the effect of Ag content on tribological behaviour of Ti-Ag films was studied. It was seen that temperature change to modify the humidity affects the tribological behaviour of polymer counter-face and Ag.