An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
John Wason, William Gressick, J Wen, Jason J. Gorman, Nicholas Dagalakis
This paper describes the algorithm development and experimental results of a multi-probe micro-assembly system. The experimental testbed consists of two actuated probes, an actuated die stage, and vision feedback. The kinematics relationships for the
R M. Verkouteren, John G. Gillen, Jennifer R. Verkouteren, Robert A. Fletcher, Eric S. Windsor, Wayne Smith
Trace detection is a primary strategy for thwarting terrorism activities in the US and abroad. The development of effective reference materials and methods for this purpose relies on fundamental knowledge regarding the size, mass, morphologies, and
Eric Langlois, G. A. Shaw, J. A. Kramar, Jon R. Pratt, Donna C. Hurley
We describe a method to calibrate the spring constants of cantilevers used in atomic force microscopy (AFM) by means of a piezoresistive cantilever. Before use, the piezoresistive cantilever was calibrated with an absolute force standard, the NIST
Dianne L. Poster, John A. Small, Michael T. Postek
The National Nanotechnology Initiative (NNI) in its 2006 document, Environmental, Health, and Safety Research Needs for Engineered Nanoscale Materials (available at www.nano.gov), identifies standards and standard measurement protocols as a critical
We describe contact-resonance atomic force microscopy (AFM) methods to quantitatively measure Poisson's ratio v or shear modulus G at the same time as Young's modulus E. In contact-resonance AFM, the frequencies of the cantilever's resonant vibrations are
Automated scanned probe lithography has been employed to form nanoscale Cu structures through electroless metal deposition onto patterned carboxylic acid terminated self-assembled monolayers. Using this approach, Cu structures of ~ 40 nm 200 nm in lateral
Carbon nanotubes have unique properties of interest for applications in aerospace, electronics, and biotechnology. However, the properties of different batches of carbon nanotubes can vary considerably depending on chemical purity and the nanotube types
Buckmins erfullerene ion beam has been applied o he dep h profiling of an al erna ing pure P and pure Co mul ilayer. Quan i a ive dep h profiling was performed by secondary ion mass spec rome ry (SIMS) wi h C60 ions using P Co alloy films wi h differen
In-Wook Park, Jianliang Lin, William C. Moerbe, Brajendra Mishra, John J. Moore, Jennifer Anton, William D. Sproul, Kwang Ho Kim, Audrey A. Vooevodin, Evgeny A. Levashov
A number of multicomponents, nanostructured coatings have been produced for a range of tribological applications. This paper will discuss four such nanocomposite coating systems: (i) Ti-Si-B-C-N; (ii) Cr-B-N; (iii) TiC-C and (iv) Cr-Al-N produced by
Christine M. Mahoney, Albert J. Fahey, John G. Gillen, Chang Xu, James Batteas
Secondary Ion Mass Spectrometry (SIMS) employing an SF polyatomic primary ion source was used to depth profile Poly(methyl methacrylate) (PMMA) at a series of temperatures from -75 C to 125 C where the primary glass transition for PMMA occurs at 105 C. The
Christine M. Mahoney, Albert J. Fahey, John G. Gillen
Secondary Ion Mass Spectrometry (SIMS) employing an SF5+ polyatomic primary ion source was used to depth profile Poly(methyl methacrylate) (PMMA) at a series of temperatures from -75 oC to 125 oC, where the primary glass transition for PMMA occurs at 105
Donna C. Hurley, Malgorzata Kopycinska-Mueller, Tony B. Kos
We are developing tools that use the atomic force microscope (AFM) to measure mechanical properties with nanoscale spatial resolution. Contact-resonance-spectroscopy techniques such as atomic force acoustic microscopy (AFAM) involve the vibrational modes
Cynthia J. Zeissler, Keana C. Scott, Richard D. Holbrook, Peter E. Barker, Yan Xiao
We are exploring methods to achieve 3D 200 nm resolution multispectral imaging with an ordinary inexpensive widefield microscope using incoherent white light sources and an electronically tunable filter. In this work, the capabilities were applied to
M S. Wagner, K Lenghaus, John G. Gillen, Michael J. Tarlov
In this study, a series of random copolymers of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) were prepared as surface-initiated polymer (SIP) films on silicon substrates using atom transfer radical polymerization. Positive and
Yuegui Zheng, Robert E. Geer, Malgorzata Kopycinska-Mueller, Donna C. Hurley
A comparative study of the elastic uniformity and modulus of single-crystal SnO2 nanobelts is presented employing two nondestructive techniques based on atomic force microscopy: differential ultrasonic force microscopy (d-UFM) and atomic force acoustic
Jaroslaw Grobelny, De-Hao D. Tsai, Doo-In Kim, Pradeep N. Namboodiri, Robert F. Cook, Michael R. Zachariah
Scanning tunnelling microscopy (STM) imaging was performed on goldsurfaces with a large coverage of monodispersed silver nanoparticlessoft-landed on the surface from the gas phase. In both ambient and ultra-highvacuum conditions, STM scanning was found to
Dwight S. Seferos, A S. Blum, James G. Kushmerick, Guillermo Bazan
We compare scanning tunneling microscopy (STM) imaging with single molecule conductive atomic force microscopy (C-AFM) measurements by probing a series of structurally-related thiol-terminated oligo(phenylenevinylene)s (OPVs) designed to have unique charge
Marlon L. Walker, Lee J. Richter, Thomas P. Moffat
The adsorption of Cu electrodeposition accelerating agents SPS and MPS on evaporated Cu thin films was examined in-situ using spectroscopic ellipsometry under quiescent conditions. Both the thiol (MPS) and disulfide (SPS) resulted in definitive changes in
John G. Gillen, Albert J. Fahey, M Wagner, Christine M. Mahoney
Thin monolayer and bilayer filsm of spin cast poly(methyl methacrylate) (PMMA), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(lactic) acid (PLA) and PLA doped with several pharmaceuticals have been analyzed by dynamic SIMS using SF 5+ polyatomic primary
Secondary Ion Mass Spectrometry (SIMS) employing an SF5+ polyatomic primary ion source was utilized to analyze several materials commonly used in drug eluting stents (DES). Poly(ethylene-co-vinyl acetate) (PEVA), Poly(lactic-co-glycolic acid) (PLGA) and
We report on the use of the extended logistic function for fitting Auger-electron (AE) and secondary-electron (SE) linescans. Such fits provide convenient and objective measures of parameters describing the interface width and possible asymmetry of a
Christine M. Mahoney, J Yu, Albert J. Fahey, J Gardella
The use of SF5+ cluster ions for depth profiling has been successful for polymer-drug mixtures and polymer blends. This study reports results of the surface and in-depth characterization of two component blend films of poly(L-lactic acid) (PLLA) and
Christine M. Mahoney, Albert J. Fahey, John G. Gillen, Chang Xu, J Batteas
Secondary Ion Mass Spectrometry (SIMS) employing an SF5+ polyatomic primary ion source was used to depth profile through various polymeric biomaterials at a series of temperatures from -125 oC to 150 oC. The depth profile characteristics (e.g. interfacial