Abstract: Disclosed herein is a membrane scaffold comprising a planar material having a hydrophobic surface and a functional area comprising a plurality of apertures. The apertures have a diameter of from about 80 ?m to about 3000 ?m and the rims of the apertures comprise bulges extending above and/or below the surface level of the planar material. The membrane scaffold is useful in the preparation of a composite biomimetic membrane wherein functional channel forming molecules have been incorporated in said membrane.