Microalgae as a Source for Stereolithography (SLA) 3D Printing Resin

3D printers are becoming common household and laboratory appliances thanks to the possibility of producing physical objects in a short time, at low cost, with low waste, and tailored to the needs of each user. One of the most widely used types of 3D printers is stereolithography (SLA) or masked stereolithography ((m)SLA), which uses light to photo cross-link a liquid resin to solid objects layer by layer. 3D printable resins consist of numerous components, with the biggest part consisting of usually methacrylates or acrylates. However, contrary to the trend of reducing plastic consumption, the methacrylates used for SLA resins are mainly petroleum derivatives. Biobased options made with soybean oil have become commercially available in the past few years. These oils are not very sustainable as soybeans have a high demand for land and water use, and there is competition for using soy as food or feed or for materials. In contrast to soybeans, microalgae have simple nutrient requirements and do not need arable land or freshwater, excluding them from competition with crops. They also have high CO₂ fixation and can produce and store a high oil content of up to 75% by biomass weight, which can be used for the production of the resin. Here, we show how to produce 3D printable resins based on microalgal oil. Starting from commercial microalgal oil, we perform epoxidation and methacrylation reactions on it to obtain reactive groups that can be used for polymerization. Subsequently, we formulated an SLA resin that we 3D printed and analyzed for mechanical performance.