High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO 2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO 2. No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5-13.8 mm/s. By this, a better control of highpressure microfluidic platforms has been achieved.

The evolution of aerospace engines has led to a significant reduction in polluting emissions and fuel consumption, while increasing the demands placed on bearings. Hence, meeting these increasing demands for tomorrow's bearings raises the issue of producing a new material that will ensure the fatigue life and reliability. The research on high-performance material is a good opportunity to promote the introduction of powder metallurgy steel. Powder metallurgy for bearing steel manufacturing was introduced several decades ago, but the effective use in aerospace engines is still very limited. This is probably the consequence of a lack of understanding of how modern powder metallurgy steels could be used to manufacture bearings. The main interest in powder metallurgy is that it is very well adapted to increase hardness after heat treatment as a consequence of the high addition of alloying elements. Due to the fast solidification conditions, there is no specific problem concerning segregation and carbide size. In a previous symposium, we presented some data concerning ASP 2055 and the interesting metallurgy associated with this material. This article will focus on additional results concerning the mechanical and rolling contact fatigue behavior, with emphasis on toughness and microcleanliness. Thermomechanical treatment and the metallurgical evolution after each manufacturing step will be described. The main parameters concerning the formability of ASP 2055 will also be detailed. In this article, the methodology used for the metallurgical characterization will be described in detail. The mechanical results and rolling contact fatigue test results will be discussed in comparison with the well-known reference M50 vacuum induction melting/vacuum arc refining (VIM/VAR). Emphasis will be put mainly on the toughness and cleanliness assessment results. The interest in using new techniques such as microwave microscopy to reveal subsurface defects is highlighted, underlining how promising these techniques are.