RM2N 2020 Poster Abstracts


RM2N 2020

Student Poster Session


Kimberly Mackiel, Cordell Schrank, Aaron Evans, Sam Alvarado

Producing Polymer-Quantum Dot Composite Materials Through Direct Ligand Reaction

University of Wisconsin-River Falls
Department of Chemistry & Biotechnology

samuel.alvarado@uwrf.edu

Quantum dots are small semiconducting particles ranging from 1-20 nm in diameter. They can absorb and emit light. The wavelengths of light they emit correspond to their size the larger the quantum dot the longer the wavelength. They can be used in flat panel displays. As a result, the value of quantum dots has rapidly grown over the last few years. Current day quantum dot films are made by weaving large polymers through quantum dots ligands or by forming large polymer composites with quantum dot binding sites. A drawback to these methods is quantum dot aggregations. Which can reduce efficiency of the display. We are proposing a metathesis reaction that will link quantum dots through their ligands. This will allow for controllable distance between quantum dots, therefore eliminating aggregation. Some early results show that amines degrade the metathesis catalyst. To avoid this, we are switching to carboxylic acid ligands.


Jonas Wagner, David Kelm, Charles Shackett, Nicholas Hemenway (Department of Mechanical Engineering), and Gokul Gopalakrishnan (Department of Engineering Physics)

Modeling the Behavior of Silicon Nanomembranes in MEMS Sensors

University of Wisconsin-Platteville

wagnerjon@uwplatt.edu

A thin silicon membrane forms the fundamental sensing element of many Micro Electromechanical Systems (MEMS) devices. These MEMS sensors are used in applications such as touch screens, microphones, navigation systems, bioMEMS devices, and pressure measurement devices. These devices are dependent on the deformation and strain caused by external stimuli. Due to the high aspect ratio geometry, continued size reduction, and anisotropic physical properties of single crystal silicon membranes that make up the latest generation of these sensors, it is difficult to accurately predict their response to stimuli using analytical methods. We therefore use the ANSYS Workbench Finite Element Analysis (FEA) platform to investigate the deformations of different types of crystalline silicon membranes with more sophisticated computational methods. We also compare the validity of different modeling techniques to minimize the complexity of the model while maintaining accuracy. This analysis enables improvements in the design of the next generation of MEMS sensors.


Nathan Arndt, Michael Connolly, Julia Jones, Hom Kandel

Thin Film Deposition of (110) type YBCO Superconductor and Ga doped PBCO Insulator

University of Wisconsin-Parkside
Department of Physics and Mathematics

arndt014@rangers.uwp.edu

High-temperature superconductor (S) Yttrium- Barium-Copper-Oxide (YBCO) and Ga-doped doped Praseodymium-Barium-Copper-Oxides (PBCGO) insulator (I) are novel materials for the nanofabrication of S-I-S tunneling Josephson junction devices that have potential application in superconductor quantum interference biomagnetic sensors, quantum computing, and terahertz frequency detectors. YBCO based Josephson junctions offer many advantages over the conventional low temperature-based Josephson junctions in cost, cryogenic system simplicity, and high IcRn product (with Ic the junction critical current and Rn the normal resistance). We have synthesized single-phase YBCO and PBCGO polycrystalline powder materials using a solid-state reaction method and subsequently have fabricated high-density discs for the thin film deposition. In addition, we used a pulsed laser-based thin-film deposition (PLD) technique to grow (110) type thin films. Here we present our results on the synthesis/fabrication process and the structural and electrical properties of the polycrystalline powders and ceramic discs. In particular, we discuss the synthesis of the polycrystalline powders, fabrication of high-density discs, x-ray diffraction studies, and electrical transport studies of these materials.


Joel Ambriz Ponce (Department of Mathematics and Physics, University of Wisconsin-Parkside), Evan Macintosh (Computer Science Department, University of Wisconsin-Milwaukee), and William D. Parker (Department of Mathematics and Physics, University of Wisconsin-Parkside)

Pressure-Induced Phase Transition in Silicon

ambri005@rangers.uwp.edu

Silicon is an important material at the center of the microelectronics industry and has been a crucial material for testing materials modeling methods. Matter consists of atoms, and electrons drive the interactions between atoms in materials. Atomistic electronic simulations, therefore, tend to provide the best predictions for materials properties. We apply one such method, density functional theory, to the pressure phase transition of silicon from semiconducting diamond phase to metallic beta-tin phase. We present the dispersion relationship between allowed atomic vibration frequencies and vibrational direction for both phases, comparing to experiment. By squeezing the cell uniformly and relaxing atomic positions under the resulting forces, the electron total energies as a function of unit cell volume yield the pressure at which silicon transforms from a semiconductor to a metal. We aim to apply this understanding to investigate a similar transition under pressure in silicon nanomembranes.


Angelica Drees, Nathaniel Michek, Nathan Shannon, David Rohr, Dr. Gokul Gopalakrishnan, Dr. Lee Farina, Department of Engineering Physics, Dr. Jorge Camacho, Department of Mechanical Engineering, University of Wisconsin-Platteville

Faster Filtration Through Nanosculpted Silicon Membranes

michekn@uwplatt.edu

The separation of microscopic particles and biological entities such as proteins, viruses, and bacteria, is often carried out using membrane filtration. This process uses a membrane filter, typically made from a flexible polymer material several micrometers thick, with prismatic pores having parallel sidewalls. At the micro- and nano-scales, filtration through these traditional membrane systems can take significant time due to the high flow resistance arising from the membrane thickness and the pore geometry. We have developed a process to fabricate membranes with significantly reduced thickness, possessing pores with tapered sidewalls. These silicon nanomembranes are thin suspended sheets of single crystal silicon, with high strengths despite having thicknesses smaller than a micrometer. Using computational fluid dynamics to model flow rates through different types of pore geometries, we find large increases in the speed of filtration by replacing pores having parallel walls with angled sidewall pores.


Jonas Wagner, David Kelm, Charles Shackett, Nicholas Hemenway (Department of Mechanical Engineering), and Gokul Gopalakrishnan Department of Engineering Physics University of Wisconsin-Platteville

Modeling the Behavior of Silicon Nanomembranes in MEMS Sensors

kelmd@uwplatt.edu

A thin silicon membrane forms the fundamental sensing element of many Micro Electromechanical Systems (MEMS) devices. These MEMS sensors are used in applications such as touch screens, microphones, navigation systems, bioMEMS devices, and pressure measurement devices. These devices are dependent on the deformation and strain caused by external stimuli. Due to the high aspect ratio geometry, continued size reduction, and anisotropic physical properties of single crystal silicon membranes that make up the latest generation of these sensors, it is difficult to accurately predict their response to stimuli using analytical methods. We therefore use the ANSYS Workbench Finite Element Analysis (FEA) platform to investigate the deformations of different types of crystalline silicon membranes with more sophisticated computational methods. We also compare the validity of different modeling techniques to minimize the complexity of the model while maintaining accuracy. This analysis enables improvements in the design of the next generation of MEMS sensors.