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Search Publications by: Christopher Stafford (Fed)

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Displaying 176 - 198 of 198

Combinatorial Approaches for Characterizing Thin Film Bond Strength

January 1, 2005
Author(s)
Martin Chiang, D Kawaguchi, Christopher Stafford
A combinatorial approach to the edge delamination test was carried out to obtain the failure map of the epoxy/glass bond joint as a function of both temperature and film thickness. In the combinatorial test, a single specimen of an epoxy film bonded to a

Elastic Instability of Multilayer Films Coated on Substrates

January 1, 2005
Author(s)
Shu Guo, Martin Y. Chiang, Christopher M. Stafford
Mechanical properties of ultra-thin (submicrometer) films coated on a substrate are paramount in many applications. One question arises as to whether the physical and mechanical properties of supported thin films in applications can be significantly

High-Throughput Modulus Measurements of Ultra-Soft Polymer Networks

January 1, 2005
Author(s)
Elizabeth A. Wilder, Shu Guo, Martin Chiang, Christopher Stafford
A metrology for rapidly measuring the modulus of ultra-soft polymer networks has been developed. The method utilizes compression-induced buckling of a sensor film that is applied to the surface of the specimen, where the modulus-dependent buckling

Stress Analysis for Combinatorial Buckling-Based Metrology of Thin Film Modulus

January 1, 2005
Author(s)
Shu Guo, Christopher M. Stafford, Martin Y. Chiang
We recently reported on a new buckling-based metrology for probing the elastic modulus of thin polymer films. In this experimental geometry, a thin film of interest is transferred to a relatively thick elastic substrate, and buckling is induced by

A Multilens Measurement Platform for High-Throughput Adhesion Measurements

December 1, 2004
Author(s)
Aaron M. Forster, Weiping Zhang, Christopher Stafford
There are few methods available for performing high-throughput adhesion measurements. Current high-throughput methodologies for measuring interfacial adhesion rely on serial or sequential testing of discrete or continuous libraries. Alternatively, we have

A New Design for High-Throughput Peel Tests: Statistical Analysis and Example

December 1, 2004
Author(s)
A Chiche, Weiping Zhang, Christopher Stafford, Alamgir Karim
The peel test is one of the most common techniques to investigate the properties of pressure sensitive adhesives (PSAs). As the demand increases for combinatorial tools to rapidly test material performance, designinig a high-throughput peel test is a

A New 'Wrinkle' in Nanometrology

November 1, 2004
Author(s)
Christopher M. Stafford
Nanotechnology promises to revolutionize a growing set of materials applications ranging from electronics to drug delivery to ballistic protection. However, the quest to engineer mate-rials on the nanoscale (e.g., in the form of ultrathin films) is met

A Buckling-Based Metrology for Measuring the Elastic Moduli of Polymeric Thin Films

August 1, 2004
Author(s)
Christopher Stafford, Eva Simonyi, C Harrison, Kathryn Beers, Alamgir Karim, Eric J. Amis, Mark R. VanLandingham, H C. Kim, W Volksen, R D. Miller
As technology continues towards smaller, thinner and lighter devices, more stringent demands are placed on thin polymer films as diffusion barriers, dielectric coatings, electronic packaging and so on. Therefore, there is a growing need for testing

Energy Analysis of Multi-Lens Adhesion Measurements

March 1, 2004
Author(s)
Aaron M. Forster, Christopher Stafford, Alamgir Karim
The NIST Combinatorial Methods Center (NCMC) has adapted the Johnson Kendall, and Roberts (JKR) adhesive contact test for the development of a high-throughput adhesion measurement platform. This technique utilizes an array of hemispherical lenses to

High Throughput Measurement of the Elastic Modulus of Polymer Thin Films

February 1, 2004
Author(s)
Christopher M. Stafford, A Chiche, D Julthongpiput, Michael J. Fasolka
Combinatorial and High Throughput (C&HT) methods combine clever experiment design, instrument automation, and computing tools to form a new paradigm for scientific research. Given this premise, the C&HT concept is being adapted to study problems in

High-Throughput Adhesion Testing of Combinatorial Libraries With Multi-Lens Arrays

February 1, 2004
Author(s)
Aaron M. Forster, Wenhua Zhang, Christopher Stafford
The NIST Combinatorial Methods Center (NCMC) has adapted the Johnson, Kendall, and Roberts (JKR) test to develop a high-throughput adhesion measurement platform. Traditionally, the JKR test utilizes a single hemispherical lens compressed against (loading)

Peel Test Revisited Using Novel High Throughput Methods

February 1, 2004
Author(s)
A Chiche, Wenhua Zhang, Christopher Stafford
We have developed a novel combinatorial method for peel testing based on the use of gradient techniques, including surface roughness and energy, adhesive or backing layer thickness, and sample annealing temperature. The experimental design provides us with

A Rapid Prototyping Technique for the Fabrication of Solvent-Resistant Structures

October 1, 2003
Author(s)
C Harrison, J Cabral, Christopher M. Stafford, Alamgir Karim, Eric J. Amis
We demonstrate a rapid prototyping technique for the fabrication of solvent-resistant channels up to and exceeding one millimeter in height. The fabrication of channels with such dimensions by conventional lithography would be both challenging and time

High-Throughput Measurements of Polymer Adhesion and Mechanical Properties

September 1, 2003
Author(s)
Christopher Stafford, Aaron M. Forster, C Harrison, Cher H. Davis, Eric J. Amis, Alamgir Karim
Polymer adhesion is important to numerous technologies including electronic packaging, coatings and paints, biomedical implants, and pressure-sensitive adhesives. The challenge is to understand the fundamental driving forces for the development of adhesive

MeasuringThe Modulus of Polymer Films by Strain-Induced Buckling Instabilities

August 1, 2002
Author(s)
Christopher M. Stafford, C Harrison, Alamgir Karim, Eric J. Amis
We present a high-throughput technique for measuring the Young s modulus of thin polymer films. This technique exploits a strain-induced buckling instability observed in films supported on elastomeric substrates. By employing a combinatorial polymer film

Polymer Science at the NIST Combinatorial Methods Center

August 1, 2002
Author(s)
Cher H. Davis, Kathryn L. Beers, Aaron M. Forster, Christopher M. Stafford, A P. Smith, C Harrison, Weiping Zhang, Alamgir Karim, Eric J. Amis
The measurements, standards, and test methods developed by NIST, in partnership with other organizations, often help unlock the potential of new discoveries and budding technologies. Combinatorial methods are a textbook example. These emerging tools can