Microreactors are a promising technology to address U.S. needs for distributed power generation solutions associated with the electrification of the transportation and heating/cooling sectors, hydrogen production for fuel cells, and ongoing requirements for remote military installations. A key component for the commercial success of microreactors will be balance of plant turbomachinery, including compressors and blowers for gas circulation and cooling. This requirement is most obvious for gas-cooled designs, but similar needs exist for almost all currently viable microreactor configurations. Process gas lubricated foil bearings are an enabling technology that allows for simpler and more compact high performance turbomachinery designs. Large foil bearings are needed to bring these benefits to microreactor turbomachinery. This SBIR effort builds on previous work demonstrating the feasibility of large foil bearings to create commercially ready, well proven and validated designs that can be integrated into turbomachinery at acceptable levels of risk on tight development schedules. this Phase I SBIR, Xdot will evaluate innovative approaches to closing two of four technology gaps we have identified related to producing commercially ready bearings: Reliably achieving a top foil operating surface that wears in correctly and operates at a low wear rate for long life Accurately predicting thermal deformation effects at high enough fidelity to understand how they affect bearing performance and allow better bearing optimization Addressing these two gaps during Phase I will position Xdot for a Phase II effort to address the two remaining gaps related to predicting performance near bearing lift-off, and extended validation and performance testing of a large sample of bearings. Assuming the overall SBIR effort is successful, Xdot will be ready to supply well validated large foil bearings designed to enable efficient, lowmaintenance, compact, and robust high-performance balance of plant turbomachinery for the microreactor industry, developed on tight schedules with reasonable levels of risk. Adequately validated and proven large foil bearings will also enable machinery developers to address needs in the waste-water treatment industry, develop turbomachinery for future supercritical CO2 applications, and open the door for a variety of blower, circulator and compressor application requirements that traditional, smaller foil bearings cannot address.