Cura software

The skeleton of the RILZ coils is designed using Autodesk Inventor Professional software (Autodesk^® Inventor^®, v2023, California, United States) (Figure 2A). For the 3D printing of the coils, UltiMaker Cura software (UltiMaker^©, v5.2.2, Netherlands) is used. The IIIP Monoprice Delta Pro 3D Printer (Monoprice, California, United States) and the plastic material polylactic acid (PLA) (3D Printer Filament, ANYCUBIC-US, cat. no. HPLKK-103) are used. Each coil is printed in four different parts which are held together by nylon screws (Caterpillar Red, cat. no. 0727040189389) to avoid magnetic field disturbances that can be produced by metals in the coil structure. Each of the coils has 222 turns of AWG 18 gauge enamelled copper (Cetronic, cat. no. 0727040189389). In addition, the structure includes a height adjustment system to avoid interference generated by the metal trays of the incubators (Figure 2B).

A 3D model of the anode electrode was designed via Solid works software. A disc electrode with a diameter of 1.0 cm and a thickness of 0.2 mm was designed and converted to Standard Triangle Language (STL) format. Then, the as-designed disc electrode was sliced using Cura software (Ultimaker). The as-prepared filament was used to print 3D electrodes using an IRA3D FDM 3D printer. The MK10 nozzle with input and output diameters of 1.75 and 0.4 mm, respectively, was used for the printing process. The temperatures of the nozzle and bed were set to 210 °C and 60 °C, respectively, to improve the adherence of the first printed layer. The printing speed was adjusted at 40 mm s⁻¹ and the infill density was 100%. The details of the structural characterization of the as-produced filament are reported in the ESI (Fig. S4–S7†).

An open protocol for producing 3AM phantoms has been developed and released as part of an Open Science Framework project (available in the Supporting Information and hosted at osf.io/zrsp6). Required materials include an FDM 3D printer, a dual‐component “porous filament” material, a vacuum chamber, and a set of watertight containers. The protocol was used to produce all phantoms for this study.
All phantoms were designed using the open‐source Ultimaker Cura software and were printed with an Ultimaker 3 Extended 3D printer (Ultimaker, Geldermalsen, the Netherlands) loaded with GEL‐LAY filament. Unless otherwise noted, phantoms were printed with printing parameters recommended by the material vendor (Table 1), and the same pattern of parallel lines of material in each layer.
After printing, phantoms to undergo dMRI scanning were immersed in 1 L of room‐temperature tap water (~23°C) for 168 hours, then 20 mL of surfactant was added to decrease surface tension and allow the water to more easily enter the pores. The container was placed in a vacuum chamber at 1 bar for 48 hours to remove air bubbles. Finally, the phantoms were stacked in a test tube with distilled water for imaging (Figure 1C,D). Phantoms that undergo dMRI are kept in water at all times after preparation.

The scaffolds were printed using an open source 3D printer (605 S model, Shenzhen Aurora Technology Co, Shenzhen, China). The nozzle diameter of the printer was 0.4 mm, and 1.75 mm WPLA filaments with about 5% wt wood flour (Shenzhen Andsun Co, Shenzhen, China) were used in this study.
The CURA software (3.2.1 version, developed by Ultimaker) was used to set printing parameters. The printing layer height was set to 0.2 mm, the filling density to 100%, the printing speed to 30 mm·s⁻¹, the printing temperature to 200 °C, and the hot bed temperature to 60 °C.

3D models are constructed in a stereolithography (STL) format based on computed tomography scan images using 3D Slicer software. Each STL file is modified to include a connector to a load cell through Fusion 360 software (Autodesk). For the human models, STL files are downloaded from clara.io (https://clara.io/view/d49ee603-8e6c-4720-bd20-9e3d7b13978a) and are modified to various diving postures using Blender software. For 3D printing, all models are sliced using Cura software (Ultimaker Ltd.) with 40 to 50% infill and 0.2-mm layer height. Sliced files are printed in Ultimaker S5 (Ultimaker Ltd.) with with Ultimaker thermoplastic polyester (2.85 mm NFC PLA) filaments.

The Ultimaker CURA software (Version 4.12.1) was employed to define the 3D printing process settings. The layer height was set to the lowest possible value (0.06 mm) to obtain a smooth surface finish within channels. Other parameters were defined as follows: bottom/top thickness = 1.4 mm, infill density = 60%, infill pattern = grid, printing speed = 25 mm s⁻¹, and nozzle size = 0.4 mm. Using these settings, only 25 g and 21 g of tough PLA were required to manufacture the straight-RIAC and spiral-RIAC, respectively. Although a lower PLA consumption could have been potentially achieved, it was decided to manufacture a device that was mechanically robust enough to withstand many operation cycles.
During the printing process, reservoirs were oriented upward to avoid the creation of support material within them. This also allowed for accurate manufacturing of the reservoirs' bottom surfaces and frit seats. Overall, both RIAC configurations could be printed without the need for support material, as detailed in our previous study.⁴⁶