Supplementary materials (set 1 of 2) in support of "Signalling Emotions with a Breathing Soft Robot" authored by Troels Aske Klausen, Ulrich Farhadi, Evgenios Vlachos, and Jonas Jørgensen. Contents of set 1: - Design files and files to 3D print molds to manufacture the robot. Arduino code to generate movements. Files: - "STL files.zip": STL files for 3D printing molds to cast the robot. - "Arduino code.zip": Arduino code used to generate the robots movements. - "Sketch1-4.png": Design sketches for the robot design (Sketch 4 displays the selected design). - "CAD rendering of robot": Figure showing a CAD rendering of the robot. - "Physical robot.jpg": Photo of the physical robot. - "Technical drawing.png": Figure showing an overview of the mold parts and the robot's design. - "Step1-13.JPG": CAD renderings showing fabrication steps The manufacturing procedure and components and materials used are described in the paper. The data set from the human-robot interaction experiment conducted with the robot is available on Zenodo: 10.5281/zenodo.5565177