Design and Characterization of Thin-Film System for Microsensors Embedding in Ti6Al4V Alloys

Reliable structures and systems are critical for numerous engineering applications. These systems are generally operated in harsh environments. Effective monitoring and diagnosis of these structures are of critical importance. To achieve this goal, thin-film micro/nano sensors can be embedded in metal structures to protect them from external harsh environments while providing measurements with desired special and temporal resolutions and accuracy, which cannot be achieved with traditional sensors. Targeting on new sensor applications in harsh environments, this paper presents experimental results on the design and characterization of a thin-film system, including diffusion barrier and insulation layers, for a successful sensor embedding in Ti6Al4V alloy through diffusion bonding. Based on the developed material system, an effective fabrication process of the Ti6Al4V-embedded thin-film PdCr strain gages was developed. The embedded sensors were validated by a functionality test and material characterization.