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Search Publications by: Chris Long (Fed)

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Displaying 26 - 50 of 56

Carbon Nanotube Thin Film Patch Antennas for Wireless Communications

May 24, 2019
Author(s)
E. A. Bengio, Damir Senic, Lauren W. Taylor, Robert J. Headrick, Michael King, Peiyu Chen, Charles A. Little, John M. Ladbury, Chris Long, Christopher L. Holloway, Aydin Babakhani, James Booth, Nate Orloff
Early work on carbon nanotube (CNT) antennas indicated that their performance could not match that of metals such as copper. However, recent improvements in fluid phase CNT processing have yielded macroscopic CNT materials with better alignment and

NONDESTRUCTIVE, NONCONTACT QUANTIFICATION OF CARBON FIBER ALIGNMENT AND ORIENTATION BY HIGH-SPEED MICROWAVE ELLIPSOMETRY FOR TAILORABLE FEEDSTOCK

May 20, 2019
Author(s)
Nina Popovic, Shridar Yarlagadda, Dirk Heider, Edward Garboczi, Chris Long, Nate Orloff
Novel short-fiber composites facilitate the manufacture of tailorable feedstock for small formed parts. In these composites, the alignment and orientation of the short fibers must be controlled to achieve the desired composite properties. While there are

Measuring Ion-Pairing and Hydration in Variable Charge Supramolecular Cages with Microwave Microfluidics

May 17, 2019
Author(s)
Angela C. Stelson, Cynthia M. Hong, Mitchell C. Groenenboom, Charles A. Little, James C. Booth, Nathan D. Orloff, Robert G. Bergman, Kenneth N. Raymond, Kathleen A. Schwarz, F. D. Toste, Christian J. Long
MetaMetal–organic supramolecular cages can act as charged molecular containers that mediate reactions, mimic enzymatic catalysis, and selectively sequester chemicals.1,2 The hydration of these cages in solution plays a crucial role in their interactions

Label-Free Detection of Conformational Changes in Switchable DNA Nanostructures with Microwave Microfluidics

March 12, 2019
Author(s)
Angela C. Stelson, Minghui Lu, Charles A. Little, Christian J. Long, Nathan D. Orloff, Nicolas Stephanopolous, James C. Booth
Detection of conformational changes in biomolecular assemblies provides critical information into biological and self-assembly processes. State-of-the-art in situ conformation detection techniques rely on fluorescent labels or protein-specific binding

Impedance tuning with photoconductors to 40 GHz

January 22, 2019
Author(s)
Jasper A. Drisko, Ari D. Feldman, Franklyn J. Quinlan, James C. Booth, Nathan D. Orloff, Christian J. Long
Light has been widely used to control a variety of microwave devices, including switches, antennas, and detectors. Here, we present a photoconductive device integrated into a coplanar waveguide to tune complex impedances at microwave frequencies with

Measurement of Ion-Pairing Interactions in Buffer Solutions with Microwave Microfluidics

January 1, 2019
Author(s)
Charles A. Little, Angela C. Stelson, Nathan D. Orloff, Christian J. Long, James C. Booth
Broadband microwave microfluidics is an emerging technique for quantifying the frequency dependent electrical response of fluids in the microwave regime. This technique can access important physical properties including interfacial polarization, ion

Determining Carbon Fiber Composite Loading by Flip-Chip on a Coplanar Waveguide to 110GHz

November 22, 2018
Author(s)
Nina P. Basta, Jasper A. Drisko, Aaron M. Hagerstrom, Joshua A. Orlicki, Jennifer M. Sietins, Daniel B. Knorr, Jr., Edward J. Garboczi, Christian J. Long, Nathan D. Orloff
The electrical properties of materials are a necessary part of any circuit design. As applications at millimeter-wave frequen-cies increase, there is a growing need to develop new materials with low loss and multiple functionalities. Unfortunately, many

Optimizing linearity in high-speed photodiodes

November 7, 2018
Author(s)
Josue Davila-Rodriguez, X. Xie, J. Zang, Christian J. Long, Tara M. Fortier, Holly F. Leopardi, Takuma Nakamura, J. C. Campbell, Scott A. Diddams, Franklyn J. Quinlan
Analog photonic links require high fidelity, high speed optical-to-electrical conversion for applications such as radio-over-fiber, synchronization at kilometer-scale facilities, and low- noise electronic signal generation. Nonlinearity is a particularly

Determining Carbon Fiber Composite Loading with Flip-Chip Measurements to 110 GHz

September 1, 2018
Author(s)
Nina P. Basta, Aaron Hagerstrom, Jasper A. Drisko, James Booth, Edward Garboczi, Christian Long, Nathan Orloff
— Electrical properties of materials are a necessary part of any circuit design. With emerging applications at millimeter- wave frequencies, there is a need to characterize new materials before they come to market. At frequencies below about 67 GHz, it is

Sub-nanosecond Tuning of Microwave Resonators Fabricated on Ruddlesden-Popper Dielectric Thin Films

July 9, 2018
Author(s)
Aaron M. Hagerstrom, Xifeng Lu, Natalie Dawley, H. Nair, Jordi Mateu, Robert D. Horansky, Charles A. Little, James C. Booth, Christian J. Long
Voltage-tunable dielectric materials are widely used for microwave-frequency signal processing. Among tunable dielectric thin films, (SrTiO3)nSrO Ruddlesden-Popper (RP) superlattices have exceptionally low loss at high frequencies. This paper reports the

Measuring Ion-Pairing in Buffer Solutions with Microwave Microfluidics

June 14, 2018
Author(s)
Angela C. Stelson, Charles A. Little, Nathan D. Orloff, Christian J. Long, James C. Booth
Microwave microfluidics is an emergent technique for characterizing conductivity and permittivity of fluids and has wide-ranging applications in the materials science and biomedical fields. The electrical properties of fluids as a function of frequency can

How to extract distributed circuit parameters from the scattering parameters of a transmission line

January 15, 2018
Author(s)
Nathan D. Orloff, Jasper A. Drisko, Angela C. Stelson, Charles A. Little, James C. Booth, Jordi Mateu, Christian J. Long
Distributed circuit parameters parameterize the transmission and reflection off a given transmission line in terms of a distributed resistance, inductance, capacitance, and conductance, which are per unit length frequency dependent quantities. While there

Qualitative Multidimensional Calibration Comparison

January 15, 2018
Author(s)
Aric W. Sanders, Ronald A. Ginley, Christian J. Long, Jasper A. Drisko, Nathan D. Orloff, Richard A. Chamberlin
We present a technique for the visual comparison of any two vector network analyzer calibrations. This method visualizes the comparative action of the calibrations for multiple complex scattering parameters relative to the calibrated measurement plane

Characterization of Transmission Lines with Nonlinear Dielectric Materials

November 28, 2017
Author(s)
Aaron M. Hagerstrom, Christian J. Long, Nathan D. Orloff, James C. Booth, Eric J. Marksz
Nonlinear transmission lines are interesting for two broad reasons: first, they have several direct device applications (i.e. harmonic generation, and phase shifters), and second, they provide a way to characterize nonlinear materials at mm-wave

HIGH EFFICIENCY CARBON NANOTUBE THREAD ANTENNAS

November 3, 2017
Author(s)
Christopher L. Holloway, Aydin Babajgabni, Chris Long, David R. Novotny, Nate Orloff, E. A. Bengio, Damir Senic, Lauren W. Taylor, Dimitri E. Tsentalovich
Although previous research has explored the underlying theory of high-frequency behavior of carbon nanotubes (CNTs) and CNT bundles for antennas, there is a gap in the literature for direct experimental measurements of radiation efficiency. These

A Multistate Single-Connection Calibration for Microwave-Microfluidics

October 12, 2017
Author(s)
Xiao Ma, Charles A. Little, Chris Long, Jordi Mateu, James Booth, James Hwang, Nate Orloff
With emerging medical, chemical, and biological applications of microwave-microfluidic devices, many researchers desire a fast, accurate calibration that can be achieved in a single connection. However, traditional on-wafer or coaxial calibrations require

Giant surface conductivity enhancement in a carbon nanotube composite by ultraviolet light exposure

July 29, 2016
Author(s)
Christian J. Long, Nathan D. Orloff, Kevin A. Twedt, Thomas F. Lam, Luis Fernando Vargas Lara, Minhua Zhao, Bharath NMN Natarajan, Keana C. Scott, Eric Marksz, Tinh Nguyen, Jack F. Douglas, Jabez J. McClelland, Edward J. Garboczi, Jan Obrzut, James A. Liddle
Carbon nanotube composites are lightweight, multifunctional materials with readily adjustable mechanical and electrical properties—relevant to the aerospace, automotive, and sporting goods industries as high-performance building materials. Here, we combine

Cure temperature influences electrical properties via carbon nanotube-rich domain formation

July 27, 2016
Author(s)
Chelsea S. Davis, Nathan D. Orloff, Jeremiah W. Woodcock, Christian J. Long, Kevin A. Twedt, Bharath NMN Natarajan, Jonathan E. Seppala, Jabez J. McClelland, Jan Obrzut, James A. Liddle, Jeffrey W. Gilman
Carbon nanotube (CNT) nanocomposites are enticing materials that enable engineers to tailor structural and electrical properties for applications in the automotive and aerospace industries. CNT mass fraction and the matrix cure temperature are two ways to

Lightweight, flexible, high-performance carbon nanotube cables by scalable flow coating*

January 21, 2016
Author(s)
Nathan D. Orloff, Francesca Mirri, Aaron M. Forster, Rana NMN Ashkar, Robert Headrick, E. A. Bengio, Christian J. Long, April Choi, Yimin Luo, Angela R. Hight Walker, Paul Butler, Kalman D. Migler, Matteo Pasquali
Coaxial cables for data transmission are ubiquitously used in telecommunications, aerospace, automotive and robotics industries. Unfortunately, the metals used to make commercial cables are heavy and stiff. These undesirable traits are particularly

Noncontact conductivity and dielectric measurement for high throughput roll-to-roll nanomanufacturing

November 23, 2015
Author(s)
Nathan D. Orloff, Christian J. Long, Jan Obrzut, Laurent Millaud, Francesca Mirri, Thomas R. Kole, Robert D. McMichael, Mattei Pasquali, Stephan J. Stranick, James A. Liddle
Advances in roll-to-roll processing of graphene [1] and carbon nanotube [2] have at last led to the continuous production of high-quality coatings and filaments, ushering in a wave of applications for flexible [3], [4] and wearable [5] electronics, woven

The evolution of carbon nanotube network structure in unidirectional nanocomposites resolved by quantitative electron tomography

June 23, 2015
Author(s)
Bharath NMN Natarajan, Noa Lachman, Thomas F. Lam, Douglas Jacobs, Christian J. Long, Minhua Zhao, Brian L. Wardle, Renu Sharma, James A. Liddle
Carbon nanotube (CNT) reinforced polymers are next-generation, high-performance, multifunctional materials with a wide array of promising applications. The successful introduction of such materials is hampered by the lack of a quantitative understanding of