Method of forming porous three-dimensional (3d) article

A method of forming a porous three-dimensional (3D) article with an apparatus having a nozzle, said method comprising:

• I) printing a first composition on a substrate with the nozzle of the apparatus to form at least one first filament comprising the first composition;
• wherein the substrate and the nozzle are spaced a distance from one another and at least one of the substrate and the nozzle is moved at a speed relative to the other during step I);
• II) selectively controlling the distance and/or the speed such that the at least one first filament coils on the substrate to give a first layer on the substrate, the first layer comprising a coiled filament, wherein the coiled filament has a width and a period length;
• optionally, repeating steps I) and II) with independently selected composition(s) for any additional layer(s);
• and
• III) exposing the layer(s) to a solidification condition;
• wherein the porous three-dimensional (3D) article defines a plurality of voids.