Description: To improve size, weight, and power (SWaP) of spacecraft carbon dioxide (CO2) and water removal systems, Mainstream Engineering Corporation (Mainstream) developed the process to embed resistive wires directly into an additively manufactured (AM) sorbent bed for optimized regeneration. This process drastically reduces the thermal contact resistance compared to the current system of heating elements. In Phase I, Mainstream focused on developing the mechanism and process for embedding the resistive wire into the sorbent beds (three patents in progress). In Phase II, Mainstream will focus primarily on scaleup, testing, and optimization. We will optimize our paste and scale paste manufacturing to fabricate larger structures, and create separate paste formulations for CO2 and H2O adsorption. Additionally, we will improve our control system by adding additional optimization features (e.g., intra-layer wire spacing) and manufacturing improvements (e.g., refining wire lead location for wire management). We will also design an electrical control system capable of controlling current output and monitoring wire health. We will fabricate sub-scale and full-scale wire-embedded structures using these refined components for testing. We will use the sub-scale structures for accelerated life testing where we will perform accelerated adsorption cycles with standard desorption cycles to simulate long-term use. Finally, we will perform full-scale testing at representative flow rates and adsorbate concentrations to validate the integration's feasibility and expected service performance.

Benefits: For NASA, the ability to 3D print adsorbent and catalysts beds that include embedded heating/cooling elements will immediately impact various applications. We see this technology making the most significant impact for NASA in space exploration where SWaP is at a premium. Given this Phase II is expected to run until mid-2025 if awarded, with an expected TRL at completion of 6, we foresee this technology making NASA debut on DRM 8a Crewed Mars Orbital (based on the technology need date of 2027 according the NASA Technology Roadmap rev. 2015)

One or all of the advantages of our technology are beneficial to a variety of critical and high-value markets, including industrial scrubbers, pharmaceutical production, fuel cells, breathing apparatuses, and deep-sea exploration. For example, we have already proposed this technology for use in a small military submarine concept where reducing power consumption and size are paramount.