Piecewise CMC Segmentation for Fluidic Shaping

Abstract

We present a novel mesh segmentation approach for the fabrication of 3D geometries using fluidic shaping. The physics of fluidic shaping gives rise to Constant Mean Curvature (CMC) surfaces due to interfacial tension between the polymer fluid used to shape the 3D structure and an immersion fluid of equal density. Our mesh segmentation algorithm partitions the mesh into a piecewise CMC surface, such that every segment is a CMC approximation to the target within a user specified tolerance. We run a CMC evolution procedure in the loop during segmentation to find physically stable CMC surfaces that can be reliably fabricated. We extract a wireframe scaffold from the seams of this segmentation and inject polymer fluid into the frame for curing. The structure cures as a single, continuous, isotropic volume, yielding nanometer scale roughness on the interior surface of each segment without the costly post-processing or smoothing that conventional state-of-the-art approaches require for comparable surface quality.