NASA seeks to advance NASA's objective of leveraging the unique capabilities (microgravity, exposure to space) of the ISS to maintain and strengthen the U.S. leadership in the area of commercial in-space production of materials, technologies, and industries of the future that will be critical to our economic prosperity amid increasing global competition. Here we propose to meet these requirements by taking advantage of microgravity to carry out two-dimensional (2D) molybdenum disulfide (MoS2) material growth with engineered defects to meet various applications, from semiconductors and dry lubricant industry where defects are undesired and should be minimized, to biomedical diagnostics and water desalination where the thin, small (<1 nm in diameter) defects or nanopores are necessary for single molecule detection and characterization. We will design a CVD-based furnace for MoS2 growth and perform a series of terrestrial-based parameter setting studies to optimize the MoS2 growth conditions prior to leveraging the ISS facilities for a subsequent test under simulated microgravity environment in Phase II and beyond. Our innovation is directly related to the subtopic and could lead to valuable terrestrial applications and foster a scalable and sustainable demand for commercial markets in low earth orbits. The main technical objectives include 1) Develop and optimize recipes and devices for 2D MoS2 growth, and 2) Characterize the 2D MoS2 with optical microscopy, atomic-force microscopy (AFM), Raman spectroscopy and analytical TEM (bright field, HAADF and SAED).
MoS2 materials are widely used in spacecraft bearings as a solid, inorganic, dry lubricants that can tolerate prolonged exposure to the vacuum of space. Use of the ISS will facilitate validation of MoS2 growth and enable development of a US-led commercial product at reduced cost in order to attract significant capital and lead to growth of new and emerging LEO commercial markets.
MoS2 is primarily used in the automotive industry as greases for lubrication of various parts. In the defense industry, MoS2 is used for the manufacturing of premier warheads, nozzles, and shaped charge liners. The porous MoS2 membranes with defects have beneficial applications for molecular sensing, water desalination applications, energy harvesting, supercapacitors and semiconductor electronics.