Highly Expandable Foam for Lithographic 3D Printing

In modern manufacturing, it is a
widely accepted limitation that
the parts patterned by an additive or subtractive manufacturing process
(i.e., a lathe, mill, or 3D printer) must be smaller than the machine
itself that produced them. Once such parts are manufactured, they
can be postprocessed, fastened together, welded, or adhesively bonded
to form larger structures. We have developed a foaming prepolymer
resin for lithographic additive manufacturing, which can be expanded
after printing to produce parts up to 40× larger than their original
volume. This allows for the fabrication of structures significantly
larger than the build volume of the 3D printer that produced them.
Complex geometries comprised of porous foams have implications in
technologically demanding fields such as architecture, aerospace,
energy, and biomedicine. This manuscript presents a comprehensive
screening process for resin formulations, detailed analysis of printing
parameters, and observed mechanical properties of the 3D-printed foams.