A method for the manufacture of a microfluidic cell-capture chip, said method comprising the steps of: a. providing a substrate extending in an X-Y plane and having a thickness z1 in a direction Z perpendicular to said X-Y plane; said substrate comprising a regular array of through-holes in said X-Y plane; b. providing a foil, said foil extending in an X-Y plane and having a thickness z in a direction Z perpendicular to said X-Y plane, said foil comprising: i. a plurality of patch portions of said polymeric material, arranged in a regular array in said X-Y plane, each patch portion extending in said X-Y plane and having a thickness z in a direction Z perpendicular to said X-Y plane, ii. a grid portion of said polymeric material, said grid portion arranged between said patch portions in said X-Y plane and having a thickness z in a direction Z perpendicular to said X-Y plane, wherein each patch portion is connected to said grid portion in said X-Y plane by means of a release portion, said release portion having a tensile strength in the X-Y plane which is lower than the tensile strength of both said patch portions and said grid portion, such that - upon exertion of a tensile force between said patch portions and said grid portion - said foil ruptures preferentially at said release portion; wherein each of said through-holes in said substrate has a surface area in the X-Y plane which is smaller than the surface area of each patch portion of said foil in the X-Y plane, and wherein the array of through-holes is such that each through-hole of the substrate aligns with and is covered by one patch portion of said foil c. forming at least one patch-hole in each patch portion of said foil, d. overlaying the substrate with the foil such that each through-hole of the substrate aligns with and is covered by one patch portion of the foil; e. sealing each patch portion to the substrate in a continuous seal about the periphery of each through-hole; f. removing the grid portion from the substrate in a manner such that the release portions about each patch portion rupture and one patch remains sealed to the substrate about each through-hole. wherein step c. can take place at any point after step b. a. providing a substrate extending in an X-Y plane and having a thickness z1 in a direction Z perpendicular to said X-Y plane; said substrate comprising a regular array of through-holes in said X-Y plane; b. providing a foil, said foil extending in an X-Y plane and having a thickness z in a direction Z perpendicular to said X-Y plane, said foil comprising: i. a plurality of patch portions of said polymeric material, arranged in a regular array in said X-Y plane, each patch portion extending in said X-Y plane and having a thickness z in a direction Z perpendicular to said X-Y plane, ii. a grid portion of said polymeric material, said grid portion arranged between said patch portions in said X-Y plane and having a thickness z in a direction Z perpendicular to said X-Y plane, i. a plurality of patch portions of said polymeric material, arranged in a regular array in said X-Y plane, each patch portion extending in said X-Y plane and having a thickness z in a direction Z perpendicular to said X-Y plane, ii. a grid portion of said polymeric material, said grid portion arranged between said patch portions in said X-Y plane and having a thickness z in a direction Z perpendicular to said X-Y plane, c. forming at least one patch-hole in each patch portion of said foil, d. overlaying the substrate with the foil such that each through-hole of the substrate aligns with and is covered by one patch portion of the foil; e. sealing each patch portion to the substrate in a continuous seal about the periphery of each through-hole; f. removing the grid portion from the substrate in a manner such that the release portions about each patch portion rupture and one patch remains sealed to the substrate about each through-hole.