Foamed articles and methods of making the same

A method for making an additive manufactured foamed article, the method comprising:

• placing a foamable article and carbon dioxide (CO2) in a vessel, wherein the foamable article includes a solid foamable material assembled using an additive manufacturing process, wherein the solid foamable material is a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers;
• after the placing, maintaining the vessel at a first pressure and first temperature, wherein the first pressure and first temperature are a pressure and temperature at which the carbon dioxide is a liquid and the liquid carbon dioxide is soluble in the solid foamable material, and wherein the maintaining includes holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid foamable material of the foamable article;
• following the maintaining and holding, optionally exposing the infused article to a second pressure and second temperature at which the carbon dioxide remains infused within at least a portion of the solid foamable material;
• following the maintaining and holding and the optional exposing, subjecting the foamable article to a third pressure and third temperature at which the carbon dioxide infused in the solid foamable material phase transitions to a gas, thereby expanding the solid foamable material into a foamed material and forming the foamed article.