Our aim was to evaluate the potential use of Bio-MedFlex® (BMF), a new resilient, hard-carbon, thinfilm coating, as a blood journal bearing material in Cleveland Heart's continuous-flow left and right ventricular assist devices (VADs). BMF is not classified as a diamond-like carbon (DLC) and differs from other thin-film carbon coatings by its high flexural strength, radiopacity, and wear resistance. A 2-to 4-μm-thick BMF adhesion layer was deposited on the VAD journal bearing surfaces. A

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... ial DLC coating used in other clinical blood pump applications was used as a control. Durability and reliability of the BMF coating was verified in severe pump start/stop testing using 20 BMF-coated journal bearing pairs. The BMF-coated surfaces showed no coating failures, whereas 57% of the DLC bearing pairs developed scratches through the carbon coating, documenting that BMF can provide a durable coating in our blood journal bearing application. In conclusion, BMF has shown qualities that support its significant advantages as an alternative journal bearing material in Cleveland Heart pumps. Our plan includes biocompatibility testing with ongoing animal studies, endurance testing with submerged pumps running in saline, and assessment of batch coating processing capability.