COMPLIANT SUPPORT STRUCTURE FOR SUBSTRATUM USED IN PHOTOPOLYMERIZATION VAT
A compliant support structure for a substratum (e.g., a membrane) used in a photopolymerization vat for 3D printing of articles by means of photo-curing photo-sensitive materials. Three-dimensional objects form by growth, due to progressive curing of a photo-curing liquid polymer within the vat, in a space between a transparent base and an extraction plate. On the side of the transparent base facing towards the photo-curing liquid polymer, a membrane is arranged, said membrane being transparent to said radiation and being supported at its edges by a compliant support structure. The compliant support structure is flexible, allowing it to bend or flex, thereby accommodating displacement of the membrane during formation of the three-dimensional objects when the extraction plate is raised.
1 . A method for forming a three-dimensional object by photo-curing a photo-curing liquid polymer exposed to a radiation, wherein said three-dimensional object forms by growth, due to the photo-curing of said photo-curing liquid polymer, in a space between a tank base transparent to the radiation and an extraction plate, said extraction plate progressively moving away from said transparent tank base, wherein on a side of said transparent tank base facing towards said photo-curing liquid polymer, a membrane is disposed, said membrane being transparent to said radiation and supported at its edges by a compliant support structure configured to permit said membrane to be displaced, at least partially in an area beneath said object, vertically in a direction towards said extraction plate in response to said extraction plate being raised from a first position to a second position, and to return said membrane to an approximate planar orientation after said displacement, and wherein the compliant support structure flexes in response to the vertical displacement of said membrane.
2 . An apparatus for forming a three-dimensional object by photo-curing a photo-curing liquid polymer through exposure to a radiation, said apparatus including a tank for collecting said photo-curing liquid polymer, a base of the tank that is at least partially transparent to said radiation, and an extraction plate configured to move away from the base of the tank, wherein on a side of said base facing towards said photo-curing liquid polymer, a membrane is disposed, said membrane being transparent to said radiation, and being supported at its edges by a compliant support structure configured to permit said membrane to be displaced, at least partially in an area beneath said object, vertically in a direction towards said extraction plate in response to said extraction plate being raised from a first position to a second position, and to return said membrane to an approximate planar orientation after said displacement, and wherein the compliant support structure is configured to flex in response to the vertical displacement of said membrane.
3 . The apparatus of claim 2 , wherein the base of the tank comprises borosilicate glass or quartz.
4 . The apparatus of claim 2 , wherein said membrane is displaced above the base of the tank and is separated therefrom by an air gap.