At GE Research, we are combining “physics” with artificial intelligence and machine learning to advance manufacturing design, processing, and inspection, turning innovative technologies into real products and solutions across our industrial portfolio. This article provides a snapshot of how this physical plus digital transformation is evolving at GE.

Phagocytosis of particulate wear debris from arthroplasties by macrophages induces an inflammatory response that has been linked to implant loosening and premature failure of artificial joints. Inflammatory mediators released by phagocytic macrophages such as tumor necrosis factor-a (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) are believed to play a central role in the pathogenesis of aseptic loosening. The objective of this study was to characterize titanium alloy particulates that closely match wear debris found around joint arthroplasties and to study their effects on the biosynthesis of inflammatory mediators by cultured monocytes. Peripheral blood monocytes were isolated from healthy human volunteers. Monocytes were cultured in 96-well plates for 24 h, washed, and exposed to three concentrations of titanium particulates and controls from 18Ð24 h. Supernatants were assayed for TNF-α, IL-1β, IL-6, and PGE2 activity. Energy dispersive X-ray spectroscopy (EDX) verified the titanium alloy to be Ti6A14V. Scanning electron microscopy (SEM) analysis showed significant titanium particulate heterogeneity with approximately 95% of the particles <1 micrometer in diameter. SEM and EDX technology was useful in the characterization of the titanium particulates utilized for in vitro models of titanium-induced cytokine release by monocytes. Incubation of titanium particulates (in concentrations similar to those found around loosened prosthetic joints) with cultured monocytes significantly increased their production of TNF-α, IL-1β, and PGE2.

In an effort to improve the uniformity of the threshold voltage, the Schottky barrier height, and the ideality factor, Ti0.29W0.52N0.19 and W0.81N0.19 gate metal depositions have been investigated as a function of annealing conditions for GaAs based MESFET devices. Crosssectional TEM samples were made of each device. The results of these studies indicate there is a systematic and significant reaction occurring between the gate metal and the GaAs upon 850°C and 900°C rapid thermal annealing. These reactions take different forms depending on whether Ti is present or not. If Ti is absent (i.e. WN gates) then the interfacial roughness between the gate and the GaAs is less than 30Å indicating the metallization is very unreactive. The WN contacts for some gates show void formation indicative of GaAs decomposition also for some devices an amorphous layer is observed at the interface. Selected area diffraction patterns indicate only the alpha-W and beta-W2N phases are present. For the TiWN gates the interface roughness is as large as 200Å upon 900°C 10 second RTA. However no voids or interfacial amorphous layers were observed. Again only alpha-W and beta-W2N were observed in the bulk of the gates. For both systems, beta-W2N appears to form at the interface however the morphology of the beta-W2N grains are much larger for the TiWN gates. Electrical results indicate the TiWN gates have a lower ideality factor (near 1.1) and greater uniformity across the wafer compared to the WN gates. It is proposed that the presence of Ti in the gate metal aids in reducing any surface oxides thus improving the ideality and uniformity of the gate metal/GaAs contact.