Open Source Toolkit for Micro-Model Generation Using 3D Printing

Abstract

Here, we present an open source toolkit for the generation of micro-fabricated transparent models of porous media (micro-models) from image datasets using optically transparent 3D polymer additive manufacturing (3D printing or sintering). These micro-models serve as both a research and pedagogical tool, facilitating the direct visualization of drainage and imbibition within quasi-2D porous media, generated from a range of image modalities (e.g. thin section micrographs, μCT orthoslices, and conventional digital photography). Written in the MATLAB™ language and readily extendible, this open source toolkit is intended to act as enabler for community research for the study of transport in a porous media. In this work, we demonstrate the toolkit's capabilities using X-ray micro-tomographic image data. Orthoslices of scanned rocks (Berea sandstone) are cropped and segmented (binarized), then used to generate watertight 3D meshes of micro-models, which are exported as stereolithography (.stl) files: a native format to most commercially available 3D printers. The generated models are self-contained, with the inlet-outlet ports, synthetic rock matrix and transparent viewing panels printed as a single integrated unit. The open source toolkit presented here offers a more accessible and adaptive approach to micromodel fabrication, when compared to conventional etched/molded equivalents, which require highly specialized manufacturing facilities. We suggest that the availability of such a toolset will act as a major enabler for community research in porous media transport phenomena, allowing experimental quasi-2D pore networks to be generated rapidly and cost effectively using readily available additive manufacturing technologies.