2016 Project Descriptions

Application instructions

1) Review the summer 2016 NURF project descriptions (below) and select a project of interest.

2) Complete the APPLICATION, and save the file with your last name and your first name as the first words in the file name.
(Ex: Smith-Barb-2016 NURF Application)

3) Email your completed application to the project’s faculty mentor(s) for consideration, and cc: Heidi Deethardt at ndnano@nd.edu. The application deadline is Friday, February 5, 2016.

NDnano faculty will follow-up with applicants as needed.  Award notifications will begin in early March.

Please note: Students are welcome to apply for more than one project. However, please list and prioritize on your application(s) all the projects for which you have applied.

 

Want to learn more? View the project summaries written by the 2010, 2011, 2012, 20132014, and 2015 NURF recipients.

Frequently Asked Questions at http://nano.nd.edu/education/nurf-program-overview/nurf-faqs/


Project: Microfabricated structures for millimeter-wave and sub-millimeter-wave electronics

Faculty mentors:
Prof. Jonathan Chisum • Electrical Engineering • 226A Cushing Hall • 631-3915 • jchisum@nd.edu
Prof. Patrick Fay • Electrical Engineering • 261 Fitzpatrick Hall • 631-5693 • pfay@nd.edu
Prof. Lei Liu • Electrical Engineering • 208C Cushing Hall • 631-1628 • lliu3@nd.edu

2016 NURF image Chisum
DRIE-based microfabrication for fundamental-mode coaxial structures at millimeter and submillimeter wave bands.

As the demand for mobile data continues to grow at exponential rates, the wireless industry is looking toward the millimeter-wave regime (50-90 GHz) to access untapped spectrum (up to 20 GHz of contiguous spectrum) to meet this demand. For wireless networks to profitably use this band, new high-efficiency amplifiers are necessary for mobile units and base stations. Such high-efficiency amplifiers require the explicit control of impedances in not only the band of interest but the second and third harmonic bands as well (100-180 GHz and 150-270 GHz, respectively). Due to losses and practical limitations on traditionally machined coaxial interconnects, millimeter-wave and sub-millimeter-wave systems are implemented in waveguide bands, which means they are fundamentally limited to less than an octave (2:1) of bandwidth. To design the high-efficiency amplifiers and other wideband structures (e.g., transmission lines) necessary for millimeter-wave wireless communications, a microfabricated coaxial structure is necessary. Coaxial structures can support fundamental modes from DC to 100s of GHz. This NURF summer project will focus on developing a silicon-based micromachining capability based on deep reactive ion-etching (DRIE), metal deposition, and dielectric support straps for wideband (several octaves) coaxial structures in the millimeter and sub-millimeter-wave bands. Working in NDnano’s state-of-the-art nanofabrication facility, and in conjunction with one or multiple graduate students, the NURF student will perform design simulations, mask design, pattern generation, lithography, etching, and measurement in support of four main technical objectives for this project. First, demonstrate etching and metallization with high aspect ratios and dimensions commensurate with coaxial half-circuits operating from 50-300 GHz. Second, through simulations, study the tradeoff between dielectric support straps and periodically spaced posts to support coaxial center conductors with low attenuation while maintaining fundamental-mode operation. Third, characterize positional accuracy and precision of flip-bonded micromachined wafers for fully enclosed transmission line structures. These efforts will be validated with wafer-probe-based network analyzer measurements. The work in this project will provide the foundation for many follow-on projects in this frequency band. A rising junior or senior with an electrical engineering background is expected, but qualified candidates from all levels will be considered. Given the nature of microfabrication tasks, the undergraduate student will team with at least one graduate student to provide continuity and additional effort applied to the task.

 

Project: Neural networks built from ring oscillators

Faculty mentors:
Prof. Gyorgy Csaba • Electrical Engineering • 225A Cushing Hall • 631-3059 • gcsaba@nd.edu
Prof. Wolfgang Porod • Electrical Engineering • 203A Cushing Hall • 631-6376 • porod@nd.edu

Artificial neural networks are computing devices inspired by the mammalian brain: they solve complex computing and data processing problems by an interconnected network of elementary computing blocks, called artificial neurons. A practically useful neural network consists of thousands or millions of neurons. It is difficult to realize such networks by microelectronic circuit technologies, as the power consumption of the neurons adds up and makes the overall power consumption of the circuit intolerably high. The goal of this project is to design neural networks that are built from a very simple, low-power electronic circuit, a ring oscillator. Ring oscillators may be driven with very low supply voltages, they are fast, and they may be interconnected with each other in simple ways. The student selected for this project will use SPICE-like circuit simulator programs to design ring-oscillator based neural networks and analyze their behaviors. It may be possible to realize some of the simpler circuits in a test board. This project is suited for all undergraduate levels.

 

Project: Computing devices based on spin-wave interference

Faculty mentors:
Prof. Gyorgy Csaba • Electrical Engineering • 225A Cushing Hall • 631-3059 • gcsaba@nd.edu
Prof. Wolfgang Porod • Electrical Engineering • 203A Cushing Hall • 631-6376 • porod@nd.edu

2016 NURF image Csaba

Digital computers are excellent for crunching numbers, but they are not very efficient for many other tasks, such as image recognition and analyzing ‘big data’. It is believed that analog, non-Boolean devices could do much better. Our group explores new, spin-wave based computing paradigms that process information without relying on logic gates. It was well known that optical components (lenses, holograms, mirrors) can be used for fast, ultra-parallel image processing operations. However, it is difficult to integrate optical devices with standard silicon circuits. Spin waves can implement optical computing algorithms on a much more practical hardware. A large class of linear transformations (Gabor filtering, wavelet transforms, Fourier transforms) can be performed using such wave-based algorithms – the figure shows spin-waves performing a Fourier transform. These computing operations can be inserted in an image processing pipeline (IPP) or deep learning algorithm and relieve much of the workload from a CPU unit. The student selected for this project will work on micromagnetic (physics-based) simulation of the proposed computing devices and / or study, how such devices could be plugged in signal processing, image processing, and scientific computing applications. This project is suited for all undergraduate levels.

 

Project: Characterization of magneto-electric nanoparticles for cancer treatment

Faculty mentors:
Prof. Gyorgy Csaba • Electrical Engineering • 225A Cushing Hall • 631-3059 • gcsaba@nd.edu
Prof. Wolfgang Porod • Electrical Engineering • 203A Cushing Hall • 631-6376 • porod@nd.edu
Prof. Gary H. Bernstein • Electrical Engineering • 225 Cushing Hall • 631-6269 • gbernste@nd.edu

Magneto-electric nanoparticles (MENs) are a new research direction in cancer treatment and targeted drug delivery. These particles react to an external magnetic field by changing their charge and electrical polarization. The localized change in the electric field can release drugs attached to the particle and make it easier for the drugs to penetrate cancerous cells. There is experimental evidence for the effectiveness of MENs for targeting cancer cells, but very little is known about the physical mechanism of polarization and the nature of the electric fields generated. The student working on this project will use micromagnetic simulations to understand the magnetic properties of MENs. In addition, the student will use a vibrating sample magnetometer (VSM) to measure hysteresis behavior of the particles at various temperatures; design (and possibly perform) measurements that characterize the electric charge and polarization of the particles under the influence of magnetic fields; and develop a model for describing the dependence of electrical properties on the applied magnetic field.

 

Project: Waste-to-Value: Simultaneous wastewater treatment and energy production using solar photoelectrochemical fuel cells

Faculty mentor: Prof. Kyle Doudrick • Civil & Environmental Engineering and Earth Sciences • 156 Fitzpatrick Hall • 631-0305 • kdoudrick@nd.edu

The food and beverage industry produces a significant amount of wastewater each year. Despite the amount of energy available in these wastes, there have been few efforts to recovery this as a commodity. This project focuses on the use of solar-driven photoelectrochemical cells as a technology for the simultaneous treatment of wastewater and production of energy. In particular, we are interested in brewery wastewaters as these have a high energy density. Students will have the opportunity to work at the intersection of environmental engineering, materials science, and nanotechnology. During their tenure, students will synthesize nanostructured materials, characterize materials (e.g., FTIR), sample from brewery waste streams, and test various materials for their ability to degrade organic compounds and product electricity. Students will be encouraged to write their results up for inclusion in a future journal publication.

 

Project: Restrahlen band optics with surface phonon polaritons

Faculty mentor: Prof. Anthony Hoffman • Electrical Engineering • 226B Cushing Hall • 631-4103 • ajhoffman@nd.edu

Semiconductor materials are used to generate and control light over a large portion of the electromagnetic spectrum. In the far-infrared, however, light interacts very strongly with vibrations in the semiconductor crystal, making conventional materials and techniques in this so-called “Reststrahlen band” ineffective. One possible method of improving access to this portion of the spectrum is to use strongly confined surface waves on polar semiconductors to control and generate light. These surface waves, called surface phonon polaritons, are a combination of light and a crystal vibration. In this project, the student will explore how we can control the optical properties of surface phonon polaritons in the far-infrared. Work will include reflection and transmission spectroscopy in the laboratory and simple modeling. The student will also have the opportunity to fabricate samples in the Notre Dame Nanofabrication Facility. This project is appropriate for students with an interest in optics, semiconductors, or nanotechnology.

 

Project: Computing with nanomagnet logic (NML)

Faculty mentor: Prof. Sharon Hu • Computer Science & Engineering • 323A Cushing Hall • 631-6015 • shu@nd.edu

By placing nano-scale magnets in carefully crafted patterns, logic computation can be performed. Such nanomagnet logic (NML) circuits provide a drastically different way of processing data from traditional CMOS. NML circuits have many desired properties, including lower power, non-volatility, and radiation hardness. Basic structures of NML circuits have been experimentally demonstrated. Similar to other nanoscale devices, NML circuits are fundamentally more error prone than charge-based devices. The research project investigates approaches for overcoming the potentially high error rates in NML circuits. One direction involves the application of stochastic computing concepts and the other the configurable computing concepts. By participating in this project, the student will learn fascinating properties of nanomagnets, become proficient with micromagnetic simulation tools, design and simulate different stochastic or reconfigurable NML circuit structures, and investigate the performance and power of these structures. A student in computer engineering, electrical engineering, or computer science, with basic programming skills, is preferred.

 

Project: Performance and energy study of target tracking applications

Faculty mentor: Prof. Sharon Hu • Computer Science & Engineering • 323A Cushing Hall • 631-6015 • shu@nd.edu

Tracking moving targets is a fundamental operation in many applications and is a computationally demanding task. There are various approaches for solving the problem. Some of the approaches are software that runs on traditional multi-core processors or graphics processor units while others are based on non von Neumann machines such as neural networks. Different approaches lead to different accuracy, performance, and energy. To understand which approach is more desirable for certain use scenarios, evaluating different approaches with different vision benchmark suites is indispensable. By participating in this project, the student will learn the basic concepts of target tracking. Depending on the background and interests of the student, an in-depth study of one particular approach will be performed. The student will be asked to conduct performance and energy measurements of the approach and make quantitative comparisons. A student in computer engineering, electrical engineering, or computer science, with basic programming skills, is preferred.

 

Project: Perovskite solar cell

Faculty mentor: Prof. Prashant V. Kamat • Chemistry & Biochemistry • 235 Radiation Lab • 631-5411 • pkamat@nd.edu

2015nurfprojectimage_kamat_solar

In recent years, nanomaterials have emerged as the new building blocks to construct light energy harvesting assemblies.1 Efforts are being made to design high-efficiency organic metal halide hybrid structures that exhibit improved selectivity and efficiency towards light energy conversion.2,3 This project will evaluate the performance of solid state methylammonium lead halide perovskite solar cells. The summer research involves solution processed thin perovskite films on various oxide films and construction of a solar cell. These cells will then be evaluated to establish their photovoltaic properties. The role of hole scavenger such as CuSCN, PEDOT, or 2,2´,7,7´-tetrakis-(N,Ndi-p-methoxyphenylamine) 9,9´-spirobifluorene (spiro-OMeTAD) deposited onto these photoactive films will also be evaluated. The overall goal is to extend the photoresponse of the thin film solar cell into the infrared and achieve solar conversion efficiencies greater than 15%. The student will be involved in preparation of perovskite films, spectroscopic and material characterization, solar cell fabrication, and performanc evaluation. A chemistry/physics background at the sophomore level is preferred.

References
1. Kamat, P. V., Quantum Dot Solar Cells. The Next Big Thing in Photovoltaics. J
. Phys. Chem. Lett. 2013, 4, 908–918.
2. Christians, J. A.; Fung, R.; Kamat, P. V., An Inorganic Hole Conductor for Organo-Lead Halide Perovskite Solar Cells. Improved Hole Conductivity with Copper Iodide.
J. Am. Chem. Soc. 2014, 136, 758–764.
3. Manser, J. S.; Kamat, P. V., Band Filling with Charge Carriers in Organometal Halide Perovskites.
Nat. Photonics 2014, 8, 737–743.
4. Christians, J. A.; Miranda Herrera, P. A.; Kamat, P. V., Transformation of the Excited State and Photovoltaic Efficiency of CH3NH3PbI3 Perovskite upon Controlled Exposure to Humidified Air. J. Am. Chem. Soc. 2015, 137, 1530–1538.
5. Chen, Y.-S.; Manser, J. S.; Kamat, P. V., All Solution-Processed Lead Halide Perovskite-BiVO4 Tandem Assembly for Photolytic Solar Fuels Production. J. Am. Chem. Soc. 2015, 137, 974-981.

 

Project: Nanostructure assemblies for light energy conversion

Faculty mentor: Prof. Prashant V. Kamat • Chemistry & Biochemistry • 235 Radiation Lab • 631-5411 • pkamat@nd.edu

2015nurfprojectimage_kamat_light

Recent advances in the construction and characterization of graphene-semiconductor/metal nanoparticle composites in our laboratory have allowed us to develop multi-functional materials for energy conversion and storage. These next-generation composite systems may possess the capability to integrate conversion and storage of solar energy, detection and selective destruction of trace environmental contaminants, or achieve single-substrate, multi-step heterogeneous catalysis. This research project will involve synthesis of graphene-based assemblies for photocatalytic and photovoltaic conversion of light energy. The graphene oxide-semiconductor assemblies will be characterized by transmission electron microscopy, and the excited state processes will be evaluated using time-resolved emission and absorption techniques. The goal is to optimize the performance of graphene-based assembly and maximize the photoconversion efficiency.

1. Lightcap, I. V.; Kamat, P. V. Fortification of CdSe Quantum Dots with Graphene Oxide. Excited State Interactions and Light Energy Conversion. J. Am. Chem. Soc. 2012, 134, 7109–7116.
2. Lightcap, I. V.; Murphy, S.; Schumer, T.; Kamat, P. V. Electron Hopping Through Single-to-Few Layer Graphene Oxide Films. Photocatalytically Activated  Metal Nanoparticle Deposition.
J. Phys. Chem. Lett. 2012, 3, 1453-1458.
3. Lightcap, I. V.; Kamat, P. V. Graphitic Design: Prospects of Graphene-Based Nanocomposites for Solar Energy Conversion, Storage, and Sensing.
Acc. Chem. Res. 2013, ASAP article.

 

Project: DNA origami as templates for semiconductor processing

Faculty mentor: Prof. Marya Lieberman • Chemistry & Biochemistry •  271 Stepan Hall • 631-4665 • mlieberm@nd.edu

The goal of this project is to transfer spatial and chemical information from self-assembling DNA nanostructures to semiconductor substrates (see video). We have recently found that DNA origami that are stuck to silicon chips retain their shapes during fairly rough treatment such as heating to 450C or exposure to hydrophobic solvents.[1] The REU student will prepare DNA origami with different shapes and sizes and characterize them by AFM and X-ray photoelectron spectroscopy. They will clean and prepare semiconductor surfaces, deposit origami, and carry out various semiconductor processing steps that are too top secret to appear in this abstract. The main characterization methods will be AFM and XPS. If the early results are promising and the student is willing, they will learn to perform electron-beam lithography to pattern the DNA origami.[2] A student with prior AFM, XPS, or cleanroom experience is preferred; the discipline is open but probably electrical engineering, chemistry, or physics will give the best match. This project will involve keeping track of a lot of measurements and other data; we are looking for the kind of person who keeps a tidy notebook with a four-color pen. Skills such as Excel or Matlab will help with data processing. The student will have to adapt literature procedures, so some prior experience reading the primary literature would be beneficial.

References
[1] Thermal stability of DNA origami on mica, M. Pillers and M. Lieberman, 2014, J. Vac. Sci. Technol. B, 32, 040602; http://dx.doi.org/10.1116/1.4879417 [2] EBL and molecular liftoff for directed attachment of DNA nanostructures on silicon: Top-down meets bottom-up, M. Pillers, V. Goss, and M. Lieberman, 2014, Acc. Chem. Res., 47(6), 1759-1767 DOI: 10.1021/ar500001e

Project: High-speed terahertz near-field imaging with optical imaging resolution

Faculty mentor: Prof. Lei Liu • Electrical Engineering •  208C Cushing Hall • 631-1628 • lliu3@nd.edu

2016 NURF image Liu
Fig. 1. (a) Performance improved THz optical spatial modulation using mesa-array structure. (b) High-speed THz near-field imaging with optical imaging resolution.

THz near-field imaging has been demonstrated by coupling THz radiation to a passive cantilevered atomic-force-microscope (AFM) tip and measuring the scattered radiation. 2D imaging is achieved by performing a raster mechanical scan with a difficult-to-control tiny tip-to-sample distance, resulting in long image acquisition time up to several hours. This makes it impossible to observe important events that happen in millisecond with sub-wavelength scales. Furthermore, a µm- or nm-sized tip is required to achieve sub-wavelength resolution. Due to the small tip size, power coupling efficiency from a THz source to sample-under-test in this kind of system is extremely low, leading to poor imaging performance. One more fundamental drawback of this current system is the difficulty in obtaining both magnitude and phase information simultaneously. All the above problems can be solved by employing photo-induced coded-aperture imaging (PI-CAI) [1] with much improved spatial THz modulation performance [2] through the proposed mesa-array approach as shown in Fig. 1 (a). The mesa-array technique utilizes a matrix of isolated, sub-THz wavelength structures to restrict the lateral diffusion of carriers, remarkably improving both spatial resolution of the photo-induced conductive patterns (sub-wavelength, and in principle determined by the modulation light wavelength) and the modulation depth of THz waves (e.g., >100 dB expected). A transformative concept of novel THz near-field microscope with optical imaging resolution and quasi-real-time frame rate can be realized by a Ge mesa-array-on-insulator technology as shown in Fig. 1 (b). On the basis of our pervious CAI experiments, by using compressive sensing as described in [3, 4], we expect to demonstrate THz near-field imaging with approximately 200×200 pixels for an area of 1.0 mm2 with a resolution approaching 5 µm or higher and a speed of ~1 frame per second (or the so-called quasi-real-time). This approach will pave the way for building THz sensing and imaging capability for many important applications including astronomy, medical imaging, security, and defense.

References
1. A. Kannegulla, Z. Jiang, S. Rahman, M. I. B. Shams, H. G. Xing, L. Cheng, Lei Liu, “Coded-aperture imaging using photo-induced reconfigurable aperture arrays for mapping terahertz beams,” IEEE Trans. Terahertz Science and Technology, vol. 4, no. 3, pp. 321-327, 2014.
2. A. Kannegulla, M. I. B. Shams, Lei Liu, L.-J. Cheng, “Photo-induced spatial modulation of terahertz waves: opportunities and limitations,” Optics Express, in review, 2015.
3. M. I. B. Shams, Z. Jiang, S. Rahman, J. Qayyum, H. G. Xing, P. Fay, and Lei Liu, “Characterization of THz Antennas using Photo-Induced Coded Aperture Imaging,” Microwave and Optical Technology Letters, vol. 57, no. 5, pp. 1180-1184, 2015.
4. M. I. B. Shams, Z. Jiang, S. Rahman, J. Qayyum, H. G. Xing, P. Fay, and Lei Liu, “Approaching real-time THz imaging using photo-induced coded-apertures and compressed sensing,” Electron. Lett., vol. 50, no. 11, 2014.

 

Project: Fabrication of polymer nanofibers with anomalous thermal conductivity

Faculty mentor: Prof. Tengfei Luo • Aerospace & Mechanical Engineering • 371 Fitzpatrick Hall • 631-9683 • tluo@nd.edu

2015nurfprojectimage_luo
Atomic structure of a chain of polydimethylsiloxane (PDMS), a silicon-based polymer widely used in thermal management, which is a key issue in microelectronics. Inset: A fundamental unit consisting of PDMS chain.

Amorphous polymers are known as thermal insulators with a thermal conductivity of ~0.1–0.3 W/mK. However, they can be more thermally conductive than many metals if we can reform them into highly aligned nanofibers (thermal conductivity > 50 W/mK). This suggests that polymers can be used to replace metals in many heat transfer devices and equipment, such as in electronic packaging and heat exchangers, with the additional advantages of reduced weight, chemical resistance, and lower cost. In this project, undergraduate researchers will fabricate polymer fibers with nanometer diameters by ultra-drawing fibers from polymer melt. They will also characterize the nanofibers using electron microscopes and X-ray scattering, and measure thermal transport properties using scanning thermal microscopy.

 

Project: Fabrication of solid state batteries

Faculty mentor: Prof. Paul McGinn • Chemical & Biomolecular Engineering • 178 Fitzpatrick Hall • 631-6151 • pmcginn@nd.edu

2015nurfprojectimage_mcginn

Solid state batteries (SSBs) may be a key enabler for electric vehicles. A solid electrolyte can overcome many shortcomings of present technology including offering wider electrochemical voltage ranges, better chemical compatibility, and improved safety. Progress is needed to overcome electrolyte limitations and lack of economical processing, while delivering sufficient energy density for automotive application. ND researchers are developing ceramic materials and low-cost processing methods to provide for high-power, solid-state, lithium-ion batteries for use in EVs. A key factor to drive down costs is the development of scalable, ceramic fabrication techniques. The goal of this project is the processing and sintering of nanosized electrolyte powders and development of composite electrode microstructures to yield high-performance batteries. Liquid phase sintering of electrolytes will be developed to reduce required processing temperatures. Composite electrode microsctructures will be developed to most efficiently utilize active materials. The student will synthesize (annealing, milling) and characterize (X-ray diffraction) powder. Slurries for tape casting will be prepared and sintered. Cast tapes will be characterized (impedance spectroscopy). Batteries will be fabricated from tapes (glove box work). A student in materials science, chemical engineering, or chemistry is preferred.

 

Project: Implementing selective swelling agents to tailor the nanostructure and transport properties of self-assembled copolymer membranes

Faculty mentor: Prof. William A. Phillip • Chemical & Biomolecular Engineering • 121B Cushing Hall • 631-2708 • wphillip@nd.edu

2016nurfprojectimage_phillip

Nanoporous membranes based on self-assembled block polymer precursors are an emerging class of promising separation and purification devices, which will find application in water purification and biofuel processing applications, due to the ability of researchers to control the nanostructure and chemistry of these multifunctional materials. To date, the most successful methodology for directing the assembly of nanostructured block polymer-based membranes has been the self-assembly and nonsolvent induced phase separation (SNIPS) procedure. This membrane fabrication protocol combines the thermodynamically driven self-assembly of block polymers in solution with the oft-used nonsolvent induced phase separation membrane fabrication technique. In addition to being facile and scalable, the versatility of the SNIPS process makes it an attractive membrane fabrication methodology. In particular, the nanostructure generated by the SNIPS process can be tuned by varying a number of engineering parameters. This project will focus on tailoring the nanostructure of block polymer-based nanofiltration membranes through the incorporation of selective swelling agents into the membrane casting solution. The selective swelling agents will be chosen such that they partition selectively into the pore-forming block of the block polymer precursor. The guiding hypothesis is that the pore size can be tailored by adjusting the chemical identity and amount of swelling agent that is incorporated into the casting solution. The student researcher will be asked to identify potential swelling agents (with guidance from the PI and graduate students), fabricate membranes using the SNIPS process, and elucidate how the swelling agent impacts the nanostructure of the resulting membranes through experimental transport tests. The student will be involved in chemical sensor development and characterization using a spectrometer and pressure/temperature-controlled device. The sensor will be tested in a shock tube. A student from chemistry, chemical engineering, industrial engineering, mechanical engineering, or aerospace engineering is preferred.

 

Project: Nanoparticle contrast agents for spectral CT

Faculty mentor: Prof. Ryan K. Roeder • Aerospace & Mechanical Engineering • 148 Multidisciplinary Research Building • 631-7003 • rroeder@nd.edu

The student on this project will investigate the use of multiple nanoparticle contrast agents designed to leverage the capabilities of spectral computed tomography (CT) and enable quantitative molecular imaging with CT.

 

Project: Detection of tumors using immunotargeted nanoparticle contrast agents and spectral CT

Faculty mentor: Prof. Ryan K. Roeder • Aerospace & Mechanical Engineering • 148 Multidisciplinary Research Building • 631-7003 • rroeder@nd.edu

The student on this project will investigate the ability of spectral computed tomography (CT) and immunotargeted nanoparticle contrasts agents to improve sensitivity and specificity for the detection of tumors and associated abnormalities compared to conventional imaging.

 

Project: Light transmission spectroscopy: A new bio-molecular tool

Faculty mentors: Prof. Steve Ruggiero and Prof. Carol Tanner • Physics
208 Nieuwland Hall • 631-5638 • ruggiero.1@nd.edu
218 Nieuwland Hall • 631-8369 • ctanner@nd.edu

2015nurfprojectimage_ruggierotanner

Nanoparticles are common in nature as well as in many industrial applications. Engineering at the nanoscale is now becoming part of a wide range of activities, including the design of electronics and new materials. Although we may not realize it, we are surrounded by manmade and naturally occurring nanoparticles present in our air, water, food, medicines and even sometimes our cells. As such, nanoparticles have a huge impact, both good (i.e., pharmaceuticals) and bad (i.e., toxic materials, viruses, bacteria), on human and environmental health. Our new platform technology, Light Transmission Spectroscopy (LTS), has the ability to identify and accurately measure in real time the size, shape, and number of nanoparticles ranging in size from 1 to 3000 nm in diameter suspended in fluid. It has an overall performance that far exceeds previous technologies. This general tool for nanoparticle analysis has already spawned a new technique for environmental DNA identification and protein geometrical analysis. Our latest project is using the instrument as a research tool to determine the difference between cancer and normal human cells based on the size distributions sub-cellular particles. LTS represents a true game-changer in medical diagnostics, biological research, and the general advance of human health.

 

Project: Chemical sensor for fluid dynamic applications

Faculty mentor: Prof. Hirotaka Sakaue • Aerospace & Mechanical Engineering • 106 Hessert Laboratory • 631-4336 • sakaue.1@nd.edu

2016 NURF image Sakaue

This project is an interdisciplinary topic on chemistry and fluid dynamics. A chemical sensor gives luminescent output related to oxygen pressure or temperature. This sensor can be coated or sprayed onto an aerodynamic object for fluid dynamic testing. The sensor consists of a luminescent probe, porous material, polymer, and solvent. These components influence the characteristic outputs of this sensor in terms of its signal level, pressure sensitivity, temperature sensitivity, and response time. It is desired to find the relationship among those components and characteristic outputs to create an optimum sensor for various aerodynamic testing. The student will be involved in chemical sensor development and characterization using a spectrometer and pressure/temperature-controlled device. The sensor will be tested in a shock tube. A student from chemistry, chemical engineering, industrial engineering, mechanical engineering, or aerospace engineering is preferred.

 

Project: Polymer electrolytes for advanced rechargeable batteries

Faculty mentor: Prof. Jennifer Schaefer • Chemical & Biomolecular Engineering • 172 Fitzpatrick Hall • 631-5114 • jschaef6@nd.edu

The objective of the research is to investigate solid polymer electrolytes for use in lithium and/or magnesium rechargeable batteries. Such electrolytes have the potential to increase battery safety due to their lower volatility and higher thermal stability compared with commercial electrolytes. Current polymer electrolytes suffer from low ionic conductivities that result in low battery charge/discharge rates, which preclude their use in commercial devices. This project will investigate the use of novel salts and/or additives in polymer electrolyte formulations. The REU student will prepare polymer electrolyte films and characterize the electrochemical and thermal properties of these films. A chemical engineering student is preferred, but not required, though greater levels of experience in a chemical laboratory are preferred.

 

Project: Identifying nanostructure in medieval manuscripts

Faculty mentor: Prof. Zachary Schultz • Chemistry & Biochemistry g • 244 Nieuwland Hall • 631-1853 • zschultz@nd.edu

2016 NURF image Schultz
An example analysis of a 15th century manuscript is shown. A magnification of the blue “B” is shown in the inset illustrating the molecular diversity present. From the Raman spectrum shown, the mineral pigment associated with the color can be identified as azurite.  

The use of different molecular species has been used to provide color in illuminated works of art since ancient times. Distinct mineral particles, as well as organic dyes mixed with minerals are combined to provide color and decorate books and other manuscripts. The identity and composition of pigments may be linked to guilds and specific artisans. Interestingly, chemical differences associated with structure appear to play a key role in the observed properties. Using modern chemical characterization techniques, this project seeks to understand the correlation between molecular species and craftsmanship used to produce illuminated manuscripts dating from the middle ages. Interested students will be trained and use a variety of non-destructive spectroscopic techniques (e.g. Raman Spectroscopy, Hyperspectral Darkfield Imaging, and others) to examine and characterize the molecular properties in actual medieval manuscripts. This project is in collaboration with the Snite Museum of Art and the Notre Dame Nuclear Science Lab. This project is open to students at all levels, but familiarity with spectroscopy is helpful.

 

Project: Energy recovery for ultra-low energy computation

Faculty mentor: Prof. Gregory Snider • Electrical Engineering • 275 Fitzpatrick Hall • 631-4148 • gsnider@nd.edu

2016nurfprojectimage_snider
Layout of adiabatic microprocessor for ultra-low power dissipation.

Anyone who owns a laptop knows that power dissipation and the associated heat are a problem for the microelectronics industry. As electronic devices scale down in size, they use less power (and hence energy), but is there a lower limit to the energy that must be dissipated by each device? Recent experimental measurements have demonstrated our ability to measure energy dissipation in the range of a ~15 yJ (1 yJ is 10-24 J), and we are building CMOS circuits to operate in this range. Projects in the group of Professor Gregory Snider will explore the limits of ultra-low power computing, and designing, building and measuring circuits that test these limits, and clock circuits that can recycle the energy used in computation. The projects will include building circuits and amplifiers for energy measurements of the CMOS circuits as well as the actual measurements. The project will also include the design of the next generation of the adiabatic circuits. A student involved in these projects will gain experience in programming, CMOS design, and device measurement techniques through their work on the construction of circuits, writing control programs, and making measurements. Students in electrical engineering, physics, and computer science are preferred. Some knowledge of programming and soldering is helpful.

 

Project: Temperature quantization in a molecular junction

Faculty mentor: Prof. Dervis Vural • Physics • 384G Nieuwland Hall • 631-6977 • dvural@nd.edu

The thermal flow across a rod placed between two thermal reservoirs is given by Fourier’s heat equation. If we instead consider a molecular junction between two thermal reservoirs, the energy flux and hence the thermal distribution over the molecule must be quantized. Furthermore, the properties of the associated temperature operator will depend on the microscopic structure of the junction. The goals of this project is to (1) define and study a quantum temperature operator for various kinds of junctions, (2) establish its spectrum and (3) construct exotic temperature states. Since this is a theoretical study, applicants must be well versed in many-body quantum mechanics, associated mathematical techniques, and must also have a strong background in computational and numerical methods. The student will work in collaboration with the PI and one graduate student.

 

Project: Measuring surface elastic coefficients

Faculty mentor: Prof. Jonathan K. Whitmer • Chemical & Biomolecular Engineering • 122 Cushing Hall • 631-1417 • jwhitme1@nd.edu

Elastic materials exhibit a restoring force that opposes applied stress, resulting from a perturbation away from thermodynamic equilibrium. Materials may exhibit different types of elasticity depending on their character.1 Each opposed deformation defines an elastic modulus; liquid crystals may have three or more elastic moduli characterizing their response to curvature deformations in their ordering field2; solids, both crystalline and amorphous, also have several elastic moduli, such as the bulk modulus, shear modulus and Young's modulus. Each of these moduli may be related to derivatives of the system's free energy relative to a variable characterizing the extent of deformation. In this project, we look to extend recent formalisms3,4 utilizing free energy perturbation simulations to extract the elastic coefficients of liquid crystals into the domain of two-dimensional membranes and three-dimensional solids. We aim to characterize the typical elastic properties of each phase, and validate our data against previous simulations and theoretical models. During the summer project, the student will work intensively on molecular simulation models and learn techniques of advanced sampling, in particular flat-histogram methods5 used for the measurement of free energies. The student will be expected to have some familiarity with writing computer codes, preferably in C++. Beyond this, only general knowledge of physics and chemistry is required.

References
1. Landau, Lev D. and Lifshitz, E. M., Theory of Elasticity, volume 7, (Elsevier New York 1986), 3 edition.
2. P. G. de Gennes and Prost, J., The Physics of Liquid Crystals, volume 4, (Oxford University Press 1994), second edition, doi:10.1080/13583149408628646.
3. Joshi, Abhijeet A., Whitmer, Jonathan K., Guzman, Orlando, Abbott, Nicholas L., and de Pablo, Juan J., "Measuring liquid crystal elastic constants with free energy perturbations." Soft Matt., 10, 882-93 (2014), doi:10.1039/c3sm51919h.
4. Whitmer, Jonathan K., Chiu, Chi-cheng, Joshi, Abhijeet a., and de Pablo, Juan J., "Basis Function Sampling: A New Paradigm for Material Property Computation." Phys. Rev. Lett., 113, 190602 (2014), doi:10.1103/PhysRevLett.113.190602.
5. Singh, Sadanand, Chopra, Manan, and de Pablo, Juan J, "Density of states-based molecular simulations." Ann. Rev. Chem. Biochem. Eng., 3, 369-94 (2012), doi:10.1146/annurev-chembioeng-062011-081032.

 

Project: Complex coacervation

Faculty mentor: Prof. Jonathan K. Whitmer • Chemical & Biomolecular Engineering • 122 Cushing Hall • 631-1417 • jwhitme1@nd.edu

A host of interesting phenomena, both biological and technological, involve the complexation of charged polymers; these may be long polymers with well-defined secondary structure, such as proteins1, linear polyelectrolytes, or multi-branched species2. A particularly interesting phenomenon within polyelectrolyte solutions is coacervation3,4, a liquid-liquid phase separation where polymer-enriched liquid droplets are formed within a dilute phase5. Coacervation is a puzzling process where two primarily aqueous phases become immiscible6. Aggregates (coacervates) formed in mixtures of oppositely charged polyelectrolytes are known as complex coacervates5,7,8. Coacervates occur in many natural systems9,10, and have found application in microencapsulation11,12 and extraction13 processes, as their ultra-low surface tension allows them to readily assimilate nanoparticles or drug payloads within aqueous suspension. Coacervation is intimately related to the process of layer-by-layer deposition, where films up to micrometers in thickness are built by iterative surface adsorption of polyelectrolytes. These films are of interest as solid electrolytes in lightweight batteries14,15, fuel-cell electrodes14,16, protective coatings16, and drug micro-encapsulation17. Solvation and electrostatic forces bind the layers, with hydrodynamics relevant to the histories of the nonequilibrium layers. Coacervation is further related to the phase separation of charged colloidal mixtures18,19, and molecular ionic liquids-organic salts whose balance of hydrophobic and electrostatic interactions renders them liquid near room temperature20,21. As these systems exhibit common thermodynamic features, a primary goal of this research is the development of a unified theoretical and modeling framework capable of representing each system with arbitrary detail from continuum phase separation to the molecular conformations. This topic inspires two REU projects involving characterization of coacervates through molecular dynamics simulation. In each, there will be focus on utilizing coarse-grained modeling to understand the phase diagram of complex coacervates, as well as the structure and dynamics of coacervate phases. While some recent work has shown mean-field22 and PRISM23 theories capture the primary features of coacervate phases, limited simulation24 and structural characterization data exist. Thus, precise description of the phase remains elusive. In the first project, a student will utilize an open-source simulation package, such as LAMMPS25 to characterize the structure of coacervates formed by oppositely charged linear polyelectrolytes at varying compositions of added salt. Salt acts as an artificial temperature in these systems, weakening electrostatic interactions between the chains and disrupting the coacervate phase. As such, a combination of salt and temperature variation will enable precise tuning of the strength of polyelectrolyte complexation for engineering applications. In the second project, the student will examine the intriguing limit of polyelectrolyte solutions with highly valent polyoxometalate ions. Molecular simulations here will provide important information about the phase diagram, internal structure, and relaxation dynamics important for material applications. It is preferable (but not required) for students interested in this project to have prior experience with writing computer code (C++ preferred) and with scripting languages to facilitate running computations on the Whitmer group cluster and CRC machines.

References

 

Project: Design and measurement of direct bandgap laser materials for silicon-based photonics

Faculty mentor: Prof. Mark Wistey • Electrical Engineering • 266 Fitzpatrick Hall • 631-1639 • mwistey@nd.edu

Lasers are often portrayed as having destructive power. But their greatest impact may be in their computational power, since nothing moves faster than the speed of light. Replacing electrical wiring with lasers and fiber optics would make computers faster and more energy efficient. Major data centers such as Google and Amazon consume 30GW worldwide and 2% of all U.S. electricity, and much of that is in the data interconnects between cores and from core to memory. Unfortunately, semiconductors that emit light (direct bandgap) are incompatible with silicon chip fabrication. The ability to grow semiconductor lasers intimately within silicon integrated circuits is a holy grail of semiconductor research, and it now appears to be within our reach.

2016 NURF image Wistey
Figure 1: (left) Band anticrossing in Ge:C. (right) Bandgap vs. lattice constant for several HMA alloys: GaAs:N and Ge:C. Note reduced bandgap, contrary to Vegard's Law. Inset: HSE calculated conduction bands vs. %C.

Our group has developed techniques to grow dilute germanium carbide, Ge:C, which is expected to have a direct bandgap suitable for efficient lasers on silicon. Ge:C is a highly mismatched alloy (HMA) similar to GaInAs:N, as shown in the figure. The carbon atom adds a new energy state above the conduction band edge that repels the conduction band down toward the valence band. The effect is strongest in the direct valley, leading to a direct bandgap. The main challenge for Ge:C is to avoid undesirable carbon-carbon bonds, which would produce midgap trap states. We prevent C=C bonds by using gas precursors synthesized in our group that have each carbon atom already pre-bonded to four Ge atoms, providing a stable crystal. We propose to have 1-2 students model Ge:C material properties and laser designs, and to help fabricate and test these laser structures in the Notre Dame Nanofabrication Facility. Depending on the strengths and interests of the students, projects may include: performing photoluminescence, absorption, and electroluminescence measurements of selected devices; simulating band structures of Ge:C using advanced k•p or other methods; further improving our group's "universal band alignments" Matlab utility to make it generally useful to other research groups; and analyzing the emission and absorption spectra to determine laser operating parameters such as Auger recombination rates and T0. Depending on the student's interests and skills, additional project tasks may include cleanroom fabrication, photoluminescence measurements, Matlab or other programming, atomic force microscopy, and other optical and electronic characterization. Rising junior/senior electrical engineering and physics students are preferred due to stronger background in semiconductors and electronic/photonic devices, but any talented, diligent, and perseverant student will receive full consideration.

 

Project: Design and optimization of core-shell upconverting nanostructures for efficient solar cells

Faculty mentor: Prof. Mark Wistey • Electrical Engineering • 266 Fitzpatrick Hall • 631-1639 • mwistey@nd.edu

Sunlight is free, but solar power is not. Installation, permitting, inverters, and balance of system costs currently exceed the cost of some fossil fuels even if the solar cells were free. Thus improvements in $/Watt must come from increased efficiency. Existing high-efficiency solar cells use stacks of multiple semiconductors to divide the solar spectrum. But this design is expensive, and it loses efficiency near dusk and dawn when the loss of blue photons dramatically reduces total efficiency due to Kirchhoff's Current Law. An alternative approach is upconversion, in which two low-energy infrared photons create a single high energy electron. Past approaches to upconversion using impurity bands or intermediate bands have shown very low efficiency due to recombination of free carriers. Our group has proposed using core-shell upconverting nanostructures (CSUNs) to enable high efficiency solar cells at reasonable costs. CSUNs prevent recombination using two energy-ratcheting steps, each of which sacrifices a small amount of energy to prevent a larger loss. In the first step, light excites an electron across the direct bandgap of a core semiconductor, but the electron rapidly scatters to a slightly lower energy state, from which it cannot fall back to the ground state. (This is similar to the mechanism used in glow-in-the-dark paint.) From there, a second photon excites the electron to an even higher energy state over the top of an energy barrier (shell), after which it is unable to re-enter the core. The excited electron is donated directly to the host solar cell as useful electrical current. In this project, 1-2 undergraduate students will help design, simulate, and/or measure the performance of CSUNs and related materials grown in our group. The student(s) will work closely with a postdoc and/or graduate student to optimize the design of CSUN structures using Ge nanoparticles in AlAs, and also identify new material combinations that could offer even greater efficiencies. Simulations in Sentaurus TCAD and some assembly of simple test equipment are likely, with instruction from Prof. Wistey and the team. Depending on the student's interests and skills, additional project tasks may include cleanroom fabrication, photoluminescence and photoconductivity measurements, Matlab or other programming, atomic force microscopy, and other optical and electronic characterization. Rising junior/senior electrical engineering and physics students are preferred due to stronger background in semiconductors and electronic/photonic devices, but any talented, diligent, and perseverant student will receive full consideration.

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12.16.15