This Major Research Instrumentation (MRI) award supports the acquisition of a state-of-the-art table top Scanning Electron Microscope (SEM) that greatly benefits Purdue University Northwest's (PNW) research programs on topics ranging from advanced manufacturing and civil and mechanical engineering to material science and biology. The acquired SEM system will expand the research and training infrastructure, attract and retain junior faculty, and expedite current NSF-funded research at PNW. The SEM's enhanced nanotechnology capabilities will allow faculty to resolve fundamental scientific questions in these research fields--enabling significant societal benefits such as enhanced manufacturing productivity. The instrumentation will also attract qualified and motivated students to participate in high-impact research activities. This award will enhance collaboration with local industry and planned growth in academic programs. The new SEM system will be integrated into laboratory and course curricula across multiple disciplines through live demonstrations and focused projects, expanding access to undergraduate and graduate students in engineering and biological science. Outreach efforts in Northwest Indiana will use the instrument to help broaden the higher education participation of significantly underrepresented populations and to engage and benefit local industrial partners.
The SEM, with secondary and back scattering electron imaging and energy dispersive spectroscopy for elemental analysis, will help fill the gap between the magnification provided by existing optical microscopy and atomic force microscopy. The superior imaging of this new instrument, along with the embedded 3D surface roughness reconstruction algorithm, will allow researchers to better understand physical phenomena at the fundamental level. For example, to better understand process parametric relations in microfluidic device fabrications, the researchers will use SEM to evaluate and identify the resolution capacities of the master mold and resulting microstructures, such as the minimum feature size, aspect ratio, and side-wall angles for various dry film thicknesses, to achieve the required tolerance. Deterministic lateral displacement (DLD) devices fabricated with high resolutions will achieve high-efficiency focusing and separation of micro-particles by precisely controlling the particle trajectories under the drag and lift forces that can be accurately quantified. The effects of height, diameter and sidewall angle of micro-posts and their arrangement pattern in the DLD system on the unique laminar flow patterns can therefore be investigated with much higher accuracy with the superior imaging capability provided by the acquired SEM system. The SEM will also be used to study lead-free solder joint failure mechanisms by investigating the formation and growth of tin whiskers as a function of relative humidity and temperature for lead-free alloy compositions used commercially. The information obtained will provide input to models that predict tin whisker formation, which is important in helping to determine the reliability of lead-free solder joints.
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.
