The project involves acquisition of a modern field emission scanning transmission electron microscope (FE-STEM) in support of nanoscale investigations spanning a range of engineering and science fields at the South Dakota School of Mines and Technology (South Dakota Mines) and its regional research partners. The instrument will support several growing research efforts at South Dakota Mines, including energy conversion and storage, biomaterials and soft materials, 2-Dimensional (2D) materials, as well as materials designed for harsh environments and those addressing challenging environmental issues. The FE-STEM will serve five extramurally funded research centers with more than 250 participants drawn from five research universities in South Dakota and nearby states. The instrument will benefit from integration into the Engineering Mining Experimental Station (EMES) at South Dakota Mines, a central analytical characterization facility available to the South Dakota Mines campus and regional academic and industrial partners. The resulting infrastructure will provide a fertile environment for collaborative and translational research. The project extends beyond the research realm to apply the FE-STEM as a teaching and outreach tool for disseminating the excitement of the nanoworld to the general public and by integrating the instrument into existing and new courses with a commitment to teaching and mentoring students of all levels and backgrounds.<br/><br/>The project will enable quantitative structural characterization of high-entropy alloy nanoparticles and their thickness-dependent phase transition that is critical for increasing catalytic performance. Structural characterization of lithium (Li) over-stoichiometry in rock-salt based cathodes for Li ion batteries will enhance our understanding and present alternatives for conventional Li-ion batteries. A nanoscale understanding of 2D materials and their heterojunctions will elucidate their potential as single photon emitters, spontaneous parametric downconverters and ferroelectric memories for quantum information science, and aid in understanding the role of 2D hexagonal boron nitride coatings on suppressing biofilm formation and corrosion. STEM imaging and tomography will probe the 3D atomic structure of nanocomposites formed by additive manufacturing methods that can outperform conventional materials under extreme conditions. STEM will reveal the structure of black phosphor nanosheets and the efficacy of antibody targeting of cancer cells for photothermal inhibition of cancer cell migration. Correlated TEM, atomic force and fluorescence microscopy will resolve nanoscale architecture at cell membranes and correlate this with dynamical, three-dimensional live cell imaging to visualize basic cellular functions and membrane dynamics. The assembly and synthesis of nanocellulose in the plant cell wall and the structure of the enzyme complexes obtained by STEM will be correlated with single molecule fluorescence imaging to obtain a molecular scale understanding of this process.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.