2.3.3. Device Design and Fabrication

3D-printed rings were fabricated using a top down, Digital Light Processing (DLP) Gizmo® 3D printer (Gizimate® 130, Queensland, Australia) equipped with a UV light

source. Computer-aided design (CAD) files were downloaded from Thingiverse and modified using Meshmixer to design a ring suitable for the esophagus. The final dimensions of the ring CAD files were 24 mm outer diameter (OD), 20 mm height (H), and 2.5 mm cross section (CS). Standard tessellation language (STL) files were sliced at 50 µm thickness using the Gizmetor software, and printed at a continuous speed of 4 mm min−<sup>1</sup> and a light intensity of 23 mW cm−<sup>1</sup> .
