A component of a gas foil bearing, having: a plurality of material layers forming a composition gradient that defines a first coefficient of thermal expansion (CTE) and a second CTE that differs from the first CTE, wherein: the plurality of material layers include at least two dissimilar metals, plastics, or fiber filled metals or plastics, that are layered on top of each other; when the component is subject to heating, the component changes from a first shape to a second shape; and the component is a top foil.

A lubricant fluid comprising a base oil, which utilizes carboxylic esters of carboxyl di-end-capped-polyethylene glycols, or a mixture thereof, to have ultra-low viscosity, high flash point, high viscosity index (VI), excellent low temperature properties (viscosity and pour/freeze points), and low elastohydrodynamic (EHD) shear strength, and to enable the production of high efficiency fluids with enhanced temperature properties for machines or machine elements that operate in the elastohydrodynamic regime of lubrication.