Bulletin of the American Physical Society
2011 Annual Meeting of the Four Corners Section of the APS
Volume 56, Number 11
Friday–Saturday, October 21–22, 2011; Tuscon, Arizona
Session K6: Applied Physics II |
Hide Abstracts |
Chair: Koen Visscher, University of Arizona Room: UA Student Union Santa Cruz |
Saturday, October 22, 2011 8:30AM - 8:42AM |
K6.00001: Electrode-electrolyte impedance due to polarization: influence of surface roughness Brian Mazzeo, Efren Cruz Cortes, Brett Mellor Many new measurement paradigms make use of microelectrodes for interrogating liquids and biological tissues. Double-layer formation at the electrode-electrolyte interface contributes to the measured impedance of the electrode surface in series with the substance that is being measured. An empirical constant phase element is often used to model the impedance of the interface. Engineering the surface thus provides a path to reduce the influence of electrode polarization in liquid measurements. Here, the surface roughness is used to modify the interfacial impedance, greatly increasing the available bandwidth for dielectric spectroscopy of protein solutions. [Preview Abstract] |
Saturday, October 22, 2011 8:42AM - 8:54AM |
K6.00002: Dielectric function of Ni-Pt alloys from 0.6 to 6.6 eV by spectroscopic ellipsometry L.S. Abdallah, S. Zollner, C. Lavoie, A. Ozcan, M. Raymond The complex dielectric function $\varepsilon $ of metals is difficult to determine, because it depends on crystallinity, purity, native oxide, surface roughness, thickness, deposition method, etc. Nevertheless, a precise knowledge of $\varepsilon $ is useful for process control in semiconductor manufacturing. In this work, we have determined $\varepsilon $ of thin Ni-Pt alloy films (10{\%} to 25{\%} Pt, 10 nm thickness) from 0.6 to 6.6 eV using spectroscopic ellipsometry. The films were sputtered on thick SiO$_{2}$ layers to avoid reaction with the Si substrate. The ellipsometric angles (determined at three angles of incidence) were fitted using previously determined optical constants for Si and SiO$_{2}$. The optical constants for the metal were described with a Drude (free carrier) term, a pole due to lattice absorption (outside of our spectral range), and three weak interband transitions modeled with Lorentz oscillators. Variations with composition (from 10{\%} to 25{\%} Pt) and annealing at 500\r{ }C for 30s were insignificant. [Preview Abstract] |
Saturday, October 22, 2011 8:54AM - 9:06AM |
K6.00003: Carbon Nanotube Templated Microfabrication of Nickel-Plated Size Exclusion Filters Ryan Badger Carbon Nanotube Templated Microfabrication (CNT-M) is a process in which a two dimensional pattern is grown into a three dimensional structure. This method allows for high aspect ratios and good dimensional control, which are desirable qualities in nano-scale devices. CNT-M devices are often infiltrated with various materials, and in some cases it would be desirable to infiltrate CNT-M devices with metals, which are electrically conductive and catalytic for some interesting chemical reactions. Although nickel electroplating is a well-understood process, applying it to CNT growths is not. We present a method for infiltrating CNT-M structures with nickel using an electrolytic plating process. We present possible applications of this method, including a CNT-M microseive with applications in fluid and gas filtering. Using a low-stress nickel sulfamate electrolyte solution, at the proper temperature, with a pulse-plating technique, issues present in early samples were eliminated. Progress led towards a sieve with a nickel infiltrated forest, and an even nickel distribution on the surfaces of the structure. Research was focused on the development, refinement, and characterization of nickel-plated sieves produced using the method described above. [Preview Abstract] |
Saturday, October 22, 2011 9:06AM - 9:18AM |
K6.00004: Low-cost broadband RF impedance spectroscopy in micromachined microfluidic channels Shiul Khadka, Bryan Blankenagel, Matthieu Giraud-Carrier, Aaron Hawkins, Karl Warnick, Brian Mazzeo Microfluidic impedance spectroscopy can be used to detect, identify, and characterize analytes in aqueous solutions, including biological materials such as proteins. We demonstrate a low-cost microfluidic device for impedance spectroscopy of samples over a broadband frequency range (200 MHz to 20GHz). The device consists of coplanar waveguide fabricated on a low-loss Isola RF substrate using a bonded two-layer structure with a milled microfluidic channel. Transmission line parameters of the device with various solutions in the channel were measured using a vector network analyzer. These measurements are compared with results obtained from numerical simulation using HFSS (High Frequency Structure Simulator) and broadband measurements obtained with a commercial probe. The results demonstrate the ability of the fabricated device to measure varying transmission parameters due to changing sample properties. [Preview Abstract] |
Saturday, October 22, 2011 9:18AM - 9:30AM |
K6.00005: Field Performance of Photovoltaic Systems in the Tucson Desert Sean Orsburn, Adria Brooks, Daniel Cormode, James Greenberg, Garrett Hardesty, Vincent Lonij, Anas Salhab, Tyler St. Germaine, Gabe Torres, Alexander Cronin At the Tucson Electric Power (TEP) solar test yard, over 20 different grid-connected photovoltaic (PV) systems are being tested. The goal at the TEP solar test yard is to measure and model real-world performance of PV systems and to benchmark new technologies such as holographic concentrators. By studying voltage and current produced by the PV systems as a function of incident irradiance, and module temperature, we can compare our measurements of field-performance (in a harsh desert environment) to manufacturer specifications (determined under laboratory conditions). In order to measure high-voltage and high-current signals, we designed and built reliable, accurate sensors that can handle extreme desert temperatures. We will present several benchmarks of sensors in a controlled environment, including shunt resistors and Hall-effect current sensors, to determine temperature drift and accuracy. Finally we will present preliminary field measurements of PV performance for several different PV technologies. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700