Parag Banerjee, Ph.D. - US grants

1337374
Fortner

This proposal requests funding for the acquisition of a X-ray and ultraviolet photoelectron spectrometer (XPS/UPS) for Washington University in St. Louis. The greater St. Louis metropolitan region does not have an XPS/UPS instrument within a 100 mile radius and this proposal therefore fills a critical gap in the advanced analytical needs of the region. The instrument will be housed, supported and staffed in the materials characterization area of the newly formed Institute of Materials Science and Engineering (IMSE) at Washington University. The system configuration requested is designed to facilitate a wide spectrum of research, supporting XPS/UPS needs for five regional universities and three multinational corporations in eastern Missouri and southern Illinois. The VersaProbe II will come equipped with an Al K�� x-ray source to help determine chemical states of surfaces a few nanometers deep. He I and II ultraviolet sources will provide information on the valence band of materials. The system will also be equipped with mapping and imaging capabilities in the XY direction and sputter capabilities which will afford depth analysis in the Z direction. A separate glove box with a portable transfer chamber will allow air or O2 sensitive samples to be prepared and delivered to the load lock of the XPS/UPS system without risking oxidation or degradation.

Diamond coated wire sawing of silicon ingots into individual wafers accounts for 11 percent of solar cell production costs. This cost is primarily associated with generation of silicon powder which is a waste stream and requires energy intensive recycling strategies. Thinner wires can lead to minimal powder generation during wire sawing. However, thinner steel wires (smaller than 100 microns in diameter) break easily under the stress required for efficient cutting of silicon. This Grant Opportunity for Academic Liaison with Industry (GOALI) award supports scientific investigations on the use of carbon fiber wires smaller than 100 microns in diameter in diamond coated wire sawing of silicon ingots into wafers. Research results from this project will lead to reduced wastage of silicon and, therefore, reduced dollar-per-watt of silicon based solar cells.

The first research objective is to establish relationships between sawing conditions (such as wire velocity and normal force) and the chemical and structural changes of individual diamond particles coated on a carbon fiber wire. The changes observed in the diamond particles are softening (i.e., graphitization), cleavage, blunting, or complete removal from the carbon fiber wire. The approach to achieve this objective is to measure chemical and structural changes after sawing in diamond particles, carbon fiber wire, and generated silicon powder using micro-Raman spectroscopy. This technique can map chemical and structural changes in the diamond particles, carbon fiber wire and the silicon powder with micron scale spatial resolution. An industrial sawing machine, and single crystalline silicon ingots with a 15 cm x 15 cm square cross-section, will be used for sawing experiments. Wire velocities of up to 25 m/s and a normal force of up to 15 N will be used. The second research objective is to understand the effects of wear of diamond particles and carbon fiber on sawing rate. The approach to achieve this objective is to measure, in situ, wire bowing of the diamond coated carbon fiber wire as it performs sawing. This allows estimation of wire tension and frictional forces experienced by the wire inside the silicon kerf during sawing. As wear proceeds, wire bowing increases and so do frictional forces. Sawing rate will be measured as the vertical velocity of the silicon ingot as it presses down on the wire. Parameters such as carbon fiber wire diameter (from 60 µm to 100 µm) and diamond size (from 6 µm to 20 µm) will be varied.

Washington University in St. Louis proposes to acquire an instrument for patterning of micro and nanoscale features on substrates surfaces. The proposed instrument will be housed in the shared user cleanroom facility on campus. The instrument is capable of patterning two dimensional designs and three dimensional features with a spatial accuracy of 600 nanometers. This accuracy is achieved using a fine computer-guided laser beam to 'write' on a substrate covered with a light sensitive film. Once the pattern is imprinted, the light sensitive film can be used as a 'mask' for removing underlying material. Thus, the pattern is transferred from the computer generated file to the material being engineered. The availability of this unique instrument will impact nanoscale science and engineering research in the entire state of Missouri. Advanced research directly impacted with this instrument includes, but is not limited to, studying novel phenomena in nanomaterials, synthesizing unique nanostructures for efficient energy harvesting and storage, fabricating bio-inspired circuits for imaging and sensing and, engineering of devices for early disease detection and diagnostics. This instrument will be intensively used in the curricula and training program of undergraduate and graduate students at Washington University in St. Louis through two semester long courses and additional, staff-led one-on-one training. Students exposed to this instrument will become well-versed and knowledgeable in the science and engineering of micro- and nanotechnology, making them globally competitive in the high technology jobs market.

The goal of this MRI proposal is to enable new micro- and nanoscale research in numerous fields of science and engineering. This goal will be achieved through the acquisition of the Heidelberg DWL 66+ laser direct write system, which addresses significant limitations associated with available pattern transfer techniques currently available at universities and research institutions in the state of Missouri. The advanced lithographic capabilities, including gray scale exposure mode and the ability to pattern chrome masks for printing features using conventional contact lithography, will allow the fabrication of devices with a range of dimensionally-dependent behaviors: 0D (e.g., quantum dots), 1D (nanowires), 2D (Si transistor technology), and 3D (microfluidics, and micro-electromechanical (MEMS) systems). The Heidelberg DWL 66+ incorporates the best attributes of conventional patterning technologies on a single integrated platform, including (1) design / redesign flexibility, (2) rapid and concurrent patterning of large areas with sub-micron, micron and millimeter scale features, and (3) a finer ultimate resolution than optical and UV photolithography. The direct write system will impact research spanning broad length scales and applications. Research objectives supported by this instrument include: (1) property measurement of nanowires / nanosheets and devices, atomically thin crystals, superconducting quantum circuits, and polymeric and composite micro- and nanostructures, (2) bio-inspired nanoscale structures for enhanced optical sensing, noninvasive chemical sensors, microresonators for nanoscale sensing, and (3) microelectronic / microfluidic / MEMS devices featuring complex 3D nozzle profiles for targeted mechanoporation-mediated drug delivery to biological cells, microfluidic environments for cell motility studies and plasmonic and photonic devices. The broad range of micro- and nanostructures fundamental to these research projects are not accommodated by any other available lithographic instrument.

Coronary heart disease, which leads to heart attack, is the most common type of heart disease killing 380,000 people annually. It has been widely accepted that a specific molecule, the cardiac troponin I, in blood serves as a highly sensitive and specific indicator for the detection of heart attack. While there are numerous commerically available bioassays available to detect this molecule with requisite sensitivity and specificity, these tests are time consuming and require specially trained personnel. This project seeks to create a novel class of sensors which can detect cardiac troponin I with high sensitivity and extreme selectivity in resource-limited settings. The long-term impact of the proposed work is to shorten the time between the occurrence and the determination of a heart attack such that appropriate treatment can be administered rapidly thus saving lives and improving patient quality of life. The proposal will focus on hiring women and minority graduate students for conducting the above research. Opportunities for undergraduate students to conduct summer research will be provided. The project will also provide opportunities for high-school students, especially those from underrepresented groups, to participate in the micro- and nano-fabrication summer camps in the university cleanroom. The experiential learning-based science activities will directly help these high school students to prepare for colleges and improve their chances of pursuing professional STEM education.

This project will exploit the conversion of an optical signal into an electrical output on a device platform to detect the cardiac biomarker, the cardiac troponin I, with high sensitivity and specificity. The device will consist of gold nanoparticles covered with a semiconducting film and contacted by two electrodes. The conductance of the illuminated device will be determined by plasmonically induced, energetic hot electrons generated in gold nanoparticles and subsequently injected into the semiconducting film. In turn, the gold nanoparticles will be functionalized to specifically capture the target biomarker associated with heart attack. Upon cardiac troponin I binding, changes to the immediate dielectric environment will result in a shift in localized surface plasmon resonance wavelength of the gold nanoparticles. This will result in the reduction of plasmonically generated hot electron injection and hence lower the conductivity of the illuminated device. Therefore, the quantifiable loss in photoconductivity will signal the presence and concentration of the biomarker, the cardiac troponin I, for detecting heart attack.

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.

Non-Technical Description:
A traditional optical microscopy, even with the best possible spatial resolution that can be achieved, is not sufficient to study very small structures, such as the ones often found in nature, nanotechnology and small-scale engineering. In this project, an advanced scanning probe microscopy system allows scientists and engineers to overcome this limitation. Light is reflected off a nanoscale tip of the microscope to explore fine structures and discern composition of complex materials. The ability to span multiple length scales, from bulk to a scale approaching that of molecules, offers new understanding of the heterogeneities contributing to properties in complex natural and engineered systems. The project significantly enhances research and education capabilities across the boundaries of STEM (Science Technology Engineering Math) disciplines, while providing new opportunities in graduate and undergraduate research training and education. These activities serve a diverse population at the University of Central Florida (UCF), a Hispanic Serving Institution, and the Southern US.

Technical Description:
The project involves the acquisition of an integrated confocal, tip-enhanced Raman system (TERS) and tip-enhanced photoluminescence (TEPL) microscope at UCF. The platform implements the principle of tip-enhanced near-field optics on an atomic force microscope to surpass the diffraction limit of conventional Raman confocal microscopy. The TERS configuration achieves a lateral resolution of approximately 10 nm. The microscope is equipped with several excitation lasers, covering most of the visible wavelengths plus near infrared , to accommodate a wide range of research projects. The system enables interdisciplinary research to understand the structure-property relationships of a broad range of emerging materials including two-dimensional materials, perovskites, nanoparticles, biomaterials, pesticides, composites, soft tissues (e.g., plant cells), meteorites and asteroids for applications in electronics, optoelectronics, catalysis, biosensing, nanomedicine, nano-agriculture and planetary sciences.

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.

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).

Non-technical summary:
The University of Central Florida (UCF) is one of the largest universities in the USA by enrollment and is also one of the largest Hispanic Serving Institutions (HSIs) with 27,244 (38%) of Hispanic and African American students. It ranks 2nd amongst all institutions in bachelor’s degrees awarded to underrepresented minority (URM) students. The proposed PREM partnership between UCF and the University of Washington (UW) will develop a vibrant collaborative research and innovative education training program in materials, providing research and education opportunities to 15-20 URM graduate and undergraduate students. An interdisciplinary team of researchers from UCF and UW will deploy integrated theoretical and experimental approaches for the rapid discovery of advanced materials for quantum computing, low power electronics and new catalyst reactions in line with the vision set forth in the Materials Genome Initiative (MGI). Students will be co-mentored and will carry out research at both academic institutions. Exchange visits, conferences and workshops will be organized to benefit participating URM students and URM students from surrounding community colleges and universities. The PREM program will allow UCF to develop resources and infrastructure focused on accelerated emerging materials discovery while developing a long-lasting collaborative partnership with UW. The research results under the UCF-UW partnership will be disseminated in peer-reviewed journals and conference presentations. Outreach efforts will be conducted via summer boot camp, a dedicated web portal, and social media platforms.

Technical Summary
The UCF-UW partnership envisions collaborative training of under-represented minority (URM) students in cutting edge research topics to make rapid discoveries related to materials synthesis, investigation and manipulation of new physical phenomena, and theory-guided pursuit of novel quantum materials and catalysts, closely aligned to the MGI. The partnership involves two interdisciplinary research groups (IRGs). In the first IRG, time and angle resolved photoelectron spectroscopy will unravel ultrafast processes in new quantum materials including two-dimensi.onal (2D) van der Waals solids and 2D magnets. The key outcomes from this effort will reveal important dynamic processes in the femtosecond time scale and map this behavior across many different 2D materials. In the second IRG, various defects including point defects (e.g., oxygen vacancies) will be systematically introduced in catalyst materials to enable single site catalysts for low temperature CO/hydrocarbon oxidation and CO2 reduction. The key outcomes from this effort will lead to design rules for accelerated syntheses of stable, single-site heterogeneous catalyst materials. The unique syntheses, characterization and testing capabilities at UCF and world-class facilities at UW will jointly enable the exploration of the basic science of quantum and catalyst materials and provide unique opportunities for cross-fertilization of ideas, mentoring, and multidisciplinary training. The collaborative teams will hold research-focus group meetings via real-time video teleconferencing, summer internships and student exchange programs. Ultimately, this PREM program will make fundamental and rapid advances in materials research while enabling URM students to define a confident path towards their success in future professional endeavors in materials focused disciplines

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.