A slippery liquid-infused porous surface (SLIPS), liquid-impregnated surface (LIS), or multi-phase surface consists of two distinct layers. The first is a highly textured or porous substrate with features spaced sufficiently close to stably contain the second layer which is an impregnating liquid that fills in the spaces between the features. The liquid must have a surface energy well-matched to the substrate in order to form a stable film. Slippery surfaces are finding applications in commercial products, anti-fouling surfaces, anti-icing and biofilm-resistant medical devices.