DOI: 10.48436/vrxca-bm744
title: Research Data for "Two for one: Semi-crystalline and amorphous multi-material structures from greyscale printing"

description: Context and methodology

This dataset was created from original work conducted in the framework of a PhD project. It provides the raw data of results presented and discussed therein.

Technical details

Compound abbreviations in the files included herein adhere to the naming in the related publication referenced in the Related Works section, where all compounds are described in detail and drawn as structural formulas. In brief:BPLC: 1,1′-[1,1′-Biphenyl]-4,4′-diyl di-10-undecenoateCHTT: 1,2,4-cyclohexanetriethanethiol

Compound preparation: All bulk-cured samples and 3D printed samples were cured from formulations consisting of equimolar reactive end groups of BPLC and CHTT. They were cured with 1 mol% (based on terminal double bonds) of photoinitiator (2,4,6-trimethylbenzoyl)-phosphine oxide (TPO). 0.2 wt% pyrogallol were utilized as inhibitor. Detailed discussion of experimental procedures are reported in the publication.

The compressed folder "Raw Data.zip" contains the following:

Text file 'Readme.txt': Text file containing the technical details how the dataset can be used, and which is additionally listed here.

Microsoft Excel file 'Raw Data.xlsx': Tab 1: Raw data obtained via differential scanning calorimetry (DSC) of the monomer BPLC and bulk cured and 3D printed polymer samplesTab 2: Raw data obtained via dynamic mechanical analysis (DMA) of bulk cured and 3D printed polymer samplesTab 3: Raw data obtained via tensile tests of bulk cured and 3D printed polymer samplesTab 4: Raw data obtained via shape memory tests of a bulk cured polymer sampleTab 5: Raw data obtained via FTIR-VIS-spectroscopy of 3D printed polymer samplesTab 6: Raw data obtained via Density measurements of 3D printed polymer samples and the uncured formulation via the Archimedes methodTab 7: Raw data obtained via Real time photorheology measurementsTab 8: Raw data obtained via Curing depth measurements on the 3D printerTab 9: Raw data obtained via Melt rheology stability tests of the formulationTab 10: Raw data obtained via swelling study of 3D printed polymer samplesTab 11: Raw data obtained via temperature measurements of the heating and cooling cycle of a multimaterial print of one layerTab 12: Raw data obtained via Attenuated total reflection infrared spectroscopy (ATR-IR) of the uncured formulation and 3D printed polymer samples before and after post-curing

The “3D prints additional data” folder contains two sub-folders:

1. "Mesh Files": STL files for all mono-material printed parts•    TensileTest•    DMA•    Chip•    Pyramid

2. "Voxel slices" for voxel-based models of all multi-material printed parts:For the multi-material parts, where voxel-based models were used, the slices that were used to compound the printed parts are included in png format. There is currently no known standard when it comes to encoding multi-material models for light-based 3D printing (vat photopolymerization). Since we used a digital light processing (DLP) light engine with a resolution of 1920 x 1080 pixel, all images required for the light engine have to be in that format. In our voxel-based modelling environment, models can be stored as a set of images in png-format, where each image represents one printed layer. Each image is processed in the printing process as follows: If the original png image has colour information or a bit depth greater than 8, the image gets converted to a grayscale image with bit depth of 8 (which allows 28 possible values, ranging from black to white).  Each pixel is then interpreted:•    Black pixel (value: 0): Nothing is printed•    Grey pixel (value in range 1 – 254): Printed with the crystalline property•    White pixel (value: 255):  Printed with the amorphous propertyList of folders containing the voxel slices in png-format for each of the printed multi-material objects:•    "5LayerTensileTest"•    "QrCodeHidden"•    "QrCodeRegular"•    "ShapeMemoryCubeFaces"•    "Skelett"•    "WarningSign"•    "TensileTestCrossSection"

The folder "3D Printing Code" contains code for the print job programming for all types of 3D printing processes performed in the related publication. A separate readme file ("readme_printjobs.txt") is included in the zip-file for further information on how to use the provided scripts.The used python version is 3.10 and for numpy version 1.24.2 was used. The codes are therefore well-tested for these versions.The Printer-Interface in this folder (PrinterInterface.pyi) is sufficient to understand the concept and to program the printer. To make the files executable for the printer. During the code application, the import of the interface file is replaced with a concrete implementation for the used 3D printing hardware. Therefore, the code files are mainly there to demonstrate how the specific print process demonstrated in the preprint works. To reuse the code for one's own specific 3D-printer, one's own, specific implementation for the respective 3D printing hardware must be used.

The mp4 file "SupplementaryVideo_MultimaterialPrinting_GöschlLaaEtAl" has also been included in the raw data collection, displaying the heating of the multi-layer printed QR-Code, thereby deleting crystallinity in the top cover layer and revealing the QR code underneath, which is isolated from the heat via several amorphous printed layers. A detailed description of the experiment can be found in the manuscript referenced below.