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Search Publications by

Nicholas Barbosa (Fed)

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Displaying 1 - 21 of 21

Experimental study of shear and tensile properties of LIGA Ni-Fe and Ni-Co alloys at quasi-static and intermediate strain rates

April 1, 2021
Li-Anne Liew, David T. Read, May Martin, Todd R. Christenson, Peter E. Bradley, Nicholas Barbosa, Frank W. DelRio, John T. Geaney, Jeffrey Smyth
We report the in-plane shear properties, to fracture, of 200 um-thick LIGA nanocrystalline Ni- 10%Fe and micrograined Ni-10%Co. Planar simple shear specimens were designed, fabricated and pulled to fracture using a miniature commercial tension test stage

Elastic-plastic properties of mesoscale electrodeposited LIGA nickel alloy films: microscopy and mechanics

November 22, 2020
Li-Anne Liew, David T. Read, May Martin, Frank W. DelRio, Peter E. Bradley, Nicholas Barbosa, Todd R. Christenson, John T. Geaney
The elastic-plastic properties of mesoscale electrodeposited LIGA Ni alloy specimens are investigated as a function of specimen size, strain rate, and material composition. Two material compositions are studied: a high-strength fine-grained Ni-Fe alloy and

Space Commerce Workshop Report

May 13, 2020
Michelle S. Stephens, Nicholas Barbosa, Leah R. Kauffman, Rebecca Dorch, Marcus Holzinger
The Department of Commerce (DOC) Boulder Laboratories (consisting of the National Institute for Standards and Technology, the National Oceanic and Atmospheric Administration, and the National Telecommunications and Information Administration); the DOC

Potential Stable Low-Permeation Rate Standard Based on Micro-machined Silicon

December 15, 2015
Grady S. White, Adrian Verwolf, Chris M. Poling, Nicholas Barbosa, Nikki S. Rentz
Silicon wafers with micro-machined holes were evaluated for use as low permeation standard artifacts. Accuracy, stability, and reliability were assessed. Two experimental techniques were used: chilled mirror hygrometer and mass loss. The wafers exhibited a

Fatigue crack growth rates of API X70 pipeline steel in a pressurized hydrogen gas environment

December 21, 2013
Elizabeth S. Drexler, Andrew J. Slifka, Robert L. Amaro, Nicholas Barbosa, Damian S. Lauria, Louis E. Hayden, Douglas G. Stalheim
Hydrogen is known to have a deleterious effect on metal, but pipelines will still be the most cost- effective means of transporting hydrogen gas and sour gas. Rather, it is the codes and standards, such as ASME B31.12, that will guide the design of

MEMS Device for Fatigue Testing of 25 mm Thick Aluminum Specimens

June 13, 2013
Li-Anne Liew, David T. Read, Nicholas Barbosa
We report the development and demonstration of a MEMS test instrument to perform fatigue testing on 25 µm thick aluminum 1145 H19 foil. Both the foil material and the specimen fabrication were obtained from commercial sources, separate from the fabrication

MEMS-based universal fatigue test technique

August 22, 2012
Li-Anne Liew, David T. Read, Nicholas Barbosa
We have developed a MEMS (micro electro mechanical systems) -based method for fatigue testing of micro- to millimeter-sized specimens of any material (hence ‘universal’). The miniature, re- usable, stand-alone fatigue test frame is fabricated as a single

Evaluation of Thin Film Mechanical Properties by Means of Electrical Test Methods

September 30, 2007
Nicholas Barbosa, Robert Keller, David T. Read, Richard P. Vinci
The ability to measure the mechanical properties of thin films and small scale structures is essential in designing reliable components at the micro- and nano-scales. It is known that the mechanical properties of thin film materials deviate from relations

Results of a Nanoindentation Round Robin on Thin Film Copper on Silicon

January 1, 2007
David T. Read, Robert Keller, Nicholas Barbosa, Roy H. Geiss
Nanoindentation is used in a variety of fields to measure material hardness and elastic modulus. This test technique is especially attractive for thin films because of the difficulty of conducting tensile or other conventional mechanical characterization

Strain-Induced Grain Growth during Rapid Thermal Cycling of Aluminum Interconnects

January 1, 2007
Robert Keller, Roy H. Geiss, Nicholas Barbosa, Andrew Slifka, David T. Read
We demonstrate by use of automated electron backscatter diffraction (EBSD) the rapid growth of grains in non-passivated, sputtered Al-1Si interconnects during 200 Hz thermal cycling induced by alternating electric current. Mean grain diameters were

Mapping substrate/film adhesion with contact-resonance-frequency AFM

July 12, 2006
Donna C. Hurley, Malgorzata Kopycinska-Mueller, Eric Langlois, Tony B. Kos, Nicholas Barbosa
We demonstrate contact-resonance-frequency atomic force microscopy (AFM) techniques to nondestructively image variations in adhesion at a substrate/film interface. Contact-resonance-frequency imaging is a dynamic AFM technique to measure the contact

Electrical Methods for Mechanical Characterization of Interconnect Thin Films

September 1, 2005
Robert Keller, Cynthia A. Volkert, Roy H. Geiss, Andrew Slifka, David T. Read, Nicholas Barbosa, Reiner Monig
We describe the use of electrical methods for evaluating mechanical reliability and properties of patterned copper and aluminum interconnects on silicon substrates. The approach makes use of controlled Joule heating, which causes thermal strains in the