Fig. 4: Determination of minimum cavity resolution, and stiffness modulation via internal cavity printing.
From: Thin-film DLP 3D printing of multi-material parts with closed-cell internal voids
a Test model with internal cavity diameters ranging from 1 to 2 mm. b Printing success rate (hollow vs. filled) of hollow internal cavities as a function of cavity diameter, with and without inter-layer solvent washing during printing. c Designed versus printed dimensional errors as a function of cavity diameter, for samples printed with and without solvent wash. d Cubes with enclosed spherical cavities of varying design diameters, arranged in face-centered cubic (FCC) lattice structures. The prints utilize two materials: a stiff white resin (Young’s modulus = 21.9 MPa) and a softer transparent resin (Young’s modulus = 2.1 MPa), enabling mechanical contrast with the internal lattice cavity structure. e Close-up view of a printed cube fabricated with transparent resin. f, g Comparison of cyclic compression behavior for a solid cube, versus a model with internal FCC lattice cavities. The transparent resin (f) is relatively soft compared with the white resin (g). h, i Compression test results demonstrating tunability of structural stiffness.
