THE CNST NEWS
 

FALL 2013 

THE BETTER TO SEE YOU WITH: 

CNST SCIENTISTS BUILD RECORDSETTING METAMATERIAL FLAT LENS 

INSIDE 

QUANTUM DOT TECHNIQUE COMBINES BEST OF OPTICAL
 

AND ELECTRON MICROSCOPY
 

NEW COLD ATOM SOURCE FOR FOCUSED ION BEAMS
 

NANOFAB ADDS HIGH RESOLUTION X-RAY DIFFRACTION SYSTEM
 

WWW.NIST.GOV/CNST 
 

 

 

 

 

 

 

 

 

 

IN THIS ISSUE
 

From the Director | 2 

Measurement Technique 

Combines Optical and Electron 

Microscopy | 3 

Record-Setting Metamaterial 

Flat Lens | 4 

FIB Uses Cold Atomic Beam 

as Ion Source | 5 

Wideband Wavelength 

Conversion Using Cavity 

Optomechanics | 6 

Engineered Nanostructures 

Could Control Casimir Force | 7 

Stiffening DNA Nanofibers | 8 

DNA Size and Shape 

Unexpectedly Connected in 

Nanofluidic Confinement | 8 

Probing Novel Topological 

Insulators | 9 

U.S. and Korea Collaborate on 

Graphene Research | 9 

A Step Towards Energy-Efficient 

Voltage Control of Magnetic 

Devices | 10 

New Nanoscale Imaging 

Method for Plasmonics | 11 

Grayscale Technique Opens 

Third Dimension for Nanoscale 

Lithography | 12 

Nanofab Adds New X-ray 

Diffraction System | 13 

New NanoFab Equipment 

Management System | 13 

Steve Blankenship Wins 

AVS Hanyo Award | 14 

NanoFab Holiday Schedule | 14 

Introducing Blind Students 

to Nanoscale Science | 15 

Summer Students Work with 

Researchers at the CNST | 15 

CNST Releases New 

Brochure | 16 

New NanoFab Website | 16 

EDITOR | 

ROBERT RUDNITSKY 

ADDITIONAL CONTRIBUTOR | 

MARK ESSER 

GRAPHIC DESIGN | 

KRISTEN DILL 

DISCLAIMER | Certain commercial equipment, 

and software, are identified in this documentation 

to describe the subject adequately. Such 

identification does not imply recommendation 

or endorsement by the National Institute of 

Standards and Technology, nor does it imply that 

the equipment identified is necessarily the best 

available for the purpose. 

FROM THE 

DIRECTOR 

While our NanoFab users and NanoLab collaborators quickly 

recognize the skills of our world-class researchers and experienced
 

engineering staff, the CNST’s success also depends on the technical staff
 

who work behind the scenes building devices, maintaining tools, modifying
 

processes, and developing custom software for the Center.
 

Particularly important to our day-to-day operations are our Engineering Technicians, who maintain 

and upgrade all the fabrication equipment, measurement tools, and laboratory support apparatus in 

the NanoFab. They aid researchers and assist in NanoFab operations. More than anyone else, their 

careful work ensures that a process used to build a device or to take a measurement on our commercial 

state-of-the-art equipment will be replicable months later. 

Our Instrumentation Specialists, Glenn Holland and Steve Blankenship, seem able to build almost any 

mechanical device. They assist with all phases of experiment and instrumentation design. Before coming 

to the CNST, Glenn spent 22 years supporting research at the Naval Research Laboratory, performing 

computer-aided design of experimental apparatus and instruments. His designs have led to six U.S. 

Patents. Steve is an expert on computer automated design (CAD) of experimental instruments, including 

complex vacuum systems and custom vacuum components. While Steve’s main expertise is in designing 

and building surface instrumentation and thin-film and molecular beam epitaxy systems, he also has a 

broad range of skills that can be applied to any experimental situation. In October, Steve was awarded the 

2013 AVS George T. Hanyo Award “for outstanding contributions to the scanning tunneling microscopy user 

facilities and other laboratories” at the CNST. 

Our Electronics Engineers construct specialized electronic instruments for controlling state-of-the-art 

scientific experiments. Since joining NIST in 1991, Alan Band has designed and supervised the construction 

of numerous electronic instruments. Of particular note are electronic devices associated with scanning 

tunneling microscopy, scanning electron microscopy with polarization analysis, and nanofabrication with 

laser-cooled atoms. He has won numerous awards for his work at NIST, including the NIST Bronze Metal. 

David Rutter’s work at the CNST has included constructing numerous control circuits and building custom 

electronic devices for complex scanning tunneling microscopes. 

Critically important for all aspects of CNST operations, our Information Technology staff keeps our 

information secure, provides system administration to keep our servers running, maintains our IT hardware, 

and provides programming support for both NanoFab operations and NanoLab instrumentation. As 

discussed on page 13, the CNST recently launched NEMO, a new system developed from the ground up by 

CNST IT Specialist Dylan Klomparens to allow users to manage the advanced equipment in the NanoFab. 

NEMO lets users reserve NanoFab equipment in advance using a web interface, activate and deactivate 

equipment, see who is using equipment, and view equipment status. 

And keeping us safe, CNST Safety Officer and Property Manager Russ Hajdaj assists with the management 

and oversight of all aspects of the CNST Safety Program. He also manages and maintains CNST’s 

chemicals, precious metals, and property. In December 2012, along with the NanoFab staff, Russ won 

the NIST Safety Award “for establishing and implementing an outstanding safety program in the NanoFab 

that protects the safety of researchers from industry, academia, NIST, and other government agencies, who 

range from novices to experts in nanofabrication.” 

Because nanotechnology created at the CNST is frequently developed under time pressure and with very 

high standards, it is easy to lose sight of all the support that makes such progress possible. If you see a 

member of our support staff and feel it is appropriate, please thank them for their efforts. And if a staff 

member does something exceptional to help you, please let us know about it so we can recognize their 

work as well. 

Robert Celotta 

2 
3 

NEW QUANTUM DOT TECHNIQUE COMBINES THE BEST OF OPTICAL AND
 

ELECTRON MICROSCOPY
 

I

t’s not reruns of “The Jetsons”, but researchers 

working at the CNST have developed a new 

microscopy technique that uses a process similar 

to how an old tube television produces a picture— 

cathodoluminescence—to image nanoscale 

features. Combining the best features of optical 

and scanning electron microscopy, the fast, 

versatile, and high-resolution technique allows 

scientists to view surface and subsurface features 

potentially as small as 10 nanometers in size. 

The new microscopy technique, described in the 

journal AIP Advances, uses a beam of electrons 

to excite a specially engineered array of quantum 

dots, causing them to emit low-energy visible 

light very close to the surface of the sample, 

exploiting so-called “near-field” effects of light. 

By correlating the local effects of this emitted light 

with the position of the electron beam, spatial 

images of these effects can be reconstructed with 

nanometer-scale resolution. 

The technique neatly evades two problems 

in nanoscale microscopy, the diffraction limit 

that restricts conventional optical microscopes 

to resolutions no better than about half the 

wavelength of the light (so about 250 nm for green 

light), and the relatively high energies and sample 

preparation requirements of electron microscopy 

that are destructive to fragile specimens like tissue. 

CNST researcher Nikolai Zhitenev, a co-developer 

of the technique, had the idea a few years ago to 

use a phosphor coating to produce light for nearfield optical imaging, but at the time, no phosphor 

was available that was thin enough. Thick 

phosphors cause the light to diverge, severely 

limiting the image resolution. This changed when 

the NIST researchers teamed with researchers 

from a company that builds highly engineered and 

optimized quantum dots for lighting applications. 

The quantum dots potentially could do the same 

job as a phosphor, and be applied in a coating both 

homogenous and thick enough to absorb the entire 

electron beam while also sufficiently thin so that 

the light produced does not have to travel far to 

the sample. 

Much like in an old tube television where a beam of electrons moves over a phosphor screen to create images, the new 

microscopy technique works by scanning a beam of electrons over a sample that has been coated with specially engineered 

quantum dots. As shown in this schematic, the dots absorb the energy and emit it as visible light that interacts with the sample 

at close range. The scattered photons are collected using a similarly closely placed photodetector (not depicted), allowing an 

image to be constructed. 

The collaborative effort found that the quantum 

dots, which have a unique core-shell design, 

efficiently produced low-energy photons in the 

visible spectrum when energized with a beam 

of electrons. A potential thin-film light source 

in hand, the group developed a deposition 

process to bind them to specimens as a film 

with a controlled thickness of approximately 

50 nm. 

Much like in an old tube television where a beam of 

electrons moves over a phosphor screen to create 

images, the new technique works by scanning a 

beam of electrons over a sample that has been 

coated with the quantum dots. The dots absorb 

the electrons’ energy and emit it as visible light 

that interacts with and penetrates the surface over 

which it has been coated. After interacting with 

the sample, the scattered photons are collected 

using a closely placed photodetector, allowing an 

image to be constructed. The first demonstration 

of the technique was used to image the natural 

nanostructure of the photodetector itself. Because 

both the light source and detector are so close 

to the sample, the diffraction limit doesn’t apply, 

and much smaller objects can be imaged. 

“Initially, our research was driven by our desire 

to study how inhomogeneities in the structure 

of polycrystalline photovoltaics could affect the 

conversion of sunlight to electricity and how 

these devices can be improved,” says Heayoung 

Yoon, the lead author of the paper. “But we 

quickly realized that this technique could also be 

adapted to other research regimes, most notably 

imaging for biological and cellular samples, 

wet samples, samples with rough surfaces, as 

well as organic photovoltaics. We are anxious 

to make this technique available to the wider 

research community and see the results.” 

This work was a collaboration among researchers 

from NIST; the Maryland NanoCenter at the 

University of Maryland, College Park; Worcester 

Polytechnic Institute; QD Vision; and Sandia 

National Laboratories. 

High-resolution photocurrent microscopy using near-field cathodoluminescence of quantum dots, H. P. Yoon, Y. Lee, C. D. Bohn, S.-H. Ko, A. G. Gianfrancesco, J. S. Steckel, S. Coe-Sullivan, A. A. Talin, and 

N. B. Zhitenev, AIP Advances 3, 062112 (2013). 
SCIENTISTS BUILD RECORD-SETTING METAMATERIAL FLAT LENS
 

For the first time, scientists working at the CNST 

have demonstrated a new type of lens that 

bends and focuses ultraviolet (UV) light in such an 

unusual way that it can create ghostly, 3D images 

of objects that float in free space. The easy-tobuild lens could lead to improved photolithography, 

nanoscale manipulation and manufacturing, and 

even high-resolution three-dimensional imaging, 

as well as a number of as-yet-unimagined 

applications in a diverse range of fields. 

“Conventional lenses only capture two dimensions 

of a three-dimensional object,” says one of the 

paper’s co-authors, Ting Xu. “Our flat lens is able 

to project three-dimensional images of threedimensional objects that correspond one-to-one 

with the imaged object.” 

An article published in the journal Nature explains 

that the new lens is formed from a flat slab of 

metamaterial with special characteristics that 

cause light to flow backward—a counter intuitive 

situation in which waves and energy travel in 

opposite directions, creating a negative refractive 

index. 

Naturally occurring materials such as air or water 

have a positive refractive index. You can see this 

when you put a straw into a glass of water and 

look at it from the side. The straw appears bent 

and broken as a result of the change in index of 

refraction between air, which has an index of 1, and 

water, which has an index of about 1.33. Because 

the refractive indices are both positive, the portion 

of the straw immersed in the water appears bent 

forward with respect to the portion in air. 

The negative refractive index of metamaterials 

causes light entering or exiting the material to 

bend in a direction opposite what would occur 

in almost all other materials. For instance, if we 

looked at our straw placed in a glass filled with 

a negative-index material, the immersed portion 

would appear to bend backward, completely unlike 

the way we’re used to light behaving. 

In 1967, Russian physicist Victor Veselago 

described how a material with both negative 

electric permittivity and negative magnetic 

permeability would have a negative index 

Top: A CNST team has created an ultraviolet (UV) metamaterial formed of alternating nanolayers of silver (green) and titanium 

dioxide (blue). The metamaterial has an angle-independent negative refractive index, enabling it to act as a flat lens. When 

illuminated with UV light (purple) a sample object of any shape placed on the flat slab of metamaterial is projected as a threedimensional image in free space on the other side of the slab. Here a ring-shaped opening in an opaque sheet on the left of the 

slab is replicated in light on the right. Bottom left: Scanning electron micrograph of a ring-shaped opening in a chromium sheet 

located on the surface of a flat slab of metamaterial. Bottom right: Optical micrograph of the image projected beyond the slab 

under UV illumination, demonstrating that the metamaterial slab acts as a flat lens. 

of refraction. (Permittivity is a measure of a 

material’s response to an applied electric field, 

while permeability is a measure of the material’s 

response to an applied magnetic field.) 

Veselago reasoned that a material with a refractive 

index of -1 could be used to make a lens that is flat, 

as opposed to traditional refractive lenses, which 

are curved. A flat lens with a refractive index of -1 

could be used to directly image three-dimensional 

objects, projecting a three-dimensional replica into 

free space. 

A negative-index flat lens like this has also been 

predicted to enable the transfer of image details 

substantially smaller than the wavelength of 

light and create higher-resolution images than 

are possible with lenses made of positive-index 

materials such as glass. 

It took over 30 years from Veselago’s prediction for 

scientists to create a negative-index material in 

the form of metamaterials, which are engineered 

on a subwavelength scale. For the past decade, 

scientists have made metamaterials that work 

at microwave, infrared, and visible wavelengths 

by fabricating repeating metallic patterns on flat 

substrates. However, the smaller the wavelength 

of light scientists want to manipulate, the 

smaller these features need to be, which makes 

fabricating the structures an increasingly difficult 

task. Until now, making metamaterials that work 

in the UV has been impossible because it required 

making structures with features as small as 10 

nanometers, or 10 billionths of a meter. 

Moreover, because of limitations inherent in 

their design, metamaterials of this type designed 

for infrared and visible wavelengths have, so 

(continued) 

4 
5 

 

 

 

 

 

 

 

SCIENTISTS BUILD RECORD-SETTING METAMATERIAL FLAT LENS (CONT.)
 

far, been shown to impart a negative index of 

refraction to light that is traveling only in a certain 

direction, making them hard to use for imaging 

and other applications that rely on refracted light. 

To overcome these problems, researchers working 

at the CNST took inspiration from a theoretical 

metamaterial design recently proposed by a group 

at the FOM Institute for Atomic and Molecular 

Physics in Holland. They adapted the design to 

work in the UV—a frequency range of particular 

technological interest. 

According to co-authors Xu, Amit Agrawal and 

Henri Lezec, aside from achieving record-short 

wavelengths, their metamaterial lens is inherently 

easy to fabricate. It doesn’t rely on nanoscale 

patterns, but instead is a simple sandwich of 

alternating nanometer-thick layers of silver and 

titanium dioxide, the construction of which is 

routine. And because its unique design consists of 

a stack of strongly coupled waveguides sustaining 

backward waves, the metamaterial exhibits a 

negative index of refraction to incoming light 

regardless of its angle of travel. 

This realization of a Veselago flat lens operating in 

the UV is the first such demonstration of a flat lens 

at any frequency beyond the microwave. By using 

other combinations of materials, it may be possible 

to make similarly layered metamaterials for use in 

other parts of the spectrum, including the visible 

and the infrared. 

The metamaterial flat lens achieves its refractive 

action over a distance of about two wavelengths of 

UV light, about half a millionth of a meter—a focal 

length challenging to achieve with conventional 

refractive optics such as glass lenses. Furthermore, 

transmission through the metamaterial can be 

turned on and off using higher frequency light as 

a switch, allowing the flat lens to also act as a 

shutter with no moving parts. 

“Our lens will offer other researchers greater 

flexibility for manipulating UV light at small length 

scales,” says Lezec. “With its high photon energies, 

UV light has a myriad of applications, including 

photochemistry, fluorescence microscopy, and 

semiconductor manufacturing. That, and the fact 

that our lens is so easy to make, should encourage 

other researchers to explore its possibilities.” 

The new work was performed in collaboration with 

researchers from the Maryland NanoCenter at the 

University of Maryland, College Park; Syracuse 

University; and the University of British Columbia, 

Kelowna, Canada. 

All-angle negative refraction and active flat lensing of ultraviolet light, T. Xu, A. Agrawal, M. Abashin, K. J. Chau, and H. J. Lezec, Nature 497, 470–474 (2013). 

NEW ION SOURCE FOR FOCUSED ION BEAMS USES COLD ATOMIC BEAM
 

Researchers from the CNST and zeroK 

Nanotech Corporation have demonstrated a 

a region where the laser beams intersect. 

The atom beam then enters an ionizing laser 

new ion source that may enable focused ion beams beam. The result is a source with much higher 

with high brightness and resolution for nanoscale brightness than the MOTIS. High brightness 

fabrication and measurement applications in translates into an ability to focus an ion beam 

fields ranging from semiconductor manufacturing to very small dimensions because it allows more 

to biotechnology. Working under a cooperative current to be concentrated into a smaller spot. 

research and development agreement (CRADA), 

the researchers have constructed the first Based on their measurements and modeling 

prototype of a low-temperature ion source (LoTIS), 

which utilizes the extremely cold temperatures 

attainable with laser cooling to produce a highly 

collimated, bright ion beam. 

Unlike the magneto-optical trap ion source 

(MOTIS), a previous NIST technology that uses 

lasers and magnetic fields to trap and cool a group 

of atoms in three dimensions before ionizing the 

atoms and extracting a beam, LoTIS begins by 

generating a cold, but slowly moving atomic beam 

using a two-dimensional magneto-optical trap. Schematic of the LoTIS ion source. A laser-cooled and 

of the source, the researchers predict cesium 

beams created with LoTIS will have focal spot 

sizes of less than a nanometer with currents in 

the picoampere range. Such performance would 

go well beyond the capabilities of the gallium 

liquid metal ion sources commonly used in 

industry, and promises to answer key needs for 

the next generation of nanoscale manufacturing. 

Major applications for the LoTIS include 

semiconductor circuit editing and nanoscale 

secondary ion mass spectrometry (SIMS). 

The beam of atoms is then compressed and further The LoTIS technology, initially developed at NIST compressed atom beam is ionized by crossed laser beams. 

cooled to below 30 μK using counter-propagating The resulting ion beam has the requisite brightness for by the research team, has been patented and is 

polarized laser beams that slow the atoms in creating a focal spot less than a nanometer in diameter with now under license to zeroK Nanotech. 

currents in the picoampere range. 

Cold atomic beam ion source for focused ion beam applications, B. Knuffman, A. V. Steele, and J. J. McClelland, Journal of Applied Physics 114, 044303 (2013). 
 

 

WIDEBAND WAVELENGTH CONVERSION USING CAVITY OPTOMECHANICS
 

Ateam of researchers at the CNST, the 

University of Maryland, and the California 

Institute of Technology have demonstrated optical 

wavelength conversion using interactions between 

radiation pressure and mechanical vibrations in a 

nanoscale cavity optomechanical system. Along 

with recent demonstrations by other groups, 

this work shows that radiation pressure forces 

may be useful in a variety of signal transduction 

applications. In particular, wavelength conversion 

interfaces based on cavity optomechanics can 

operate over ranges and in material systems in 

which traditional frequency conversion techniques 

cannot be applied. 

Working in the CNST NanoFab allowed the 

researchers to fabricate an optomechanical 

resonator consisting of a 350 nm thick, 10 μmdiameter silicon nitride disk supported on a small 

silicon pedestal whose top is less than 200 nm in 

diameter. The microdisk simultaneously confines 

optical modes, frequencies of light that circulate 

around the disk’s periphery in “whispering gallery” 

orbits, and a mechanical “breathing” mode that 

results in the expansion and contraction of the 

disk out from its center. The disk motion, which 

changes its size, also influences the optical 

modes because their frequencies are dependent 

on the disk circumference. Additionally, the tight 

optical confinement present in these structures 

makes the radiation pressure forces strong enough 

to influence the mechanical motion. Thus, the 

system’s optics and mechanics interact with each 

other, allowing energy to be converted between 

the optical and mechanical systems. 

The researchers use the interaction of two 

whispering gallery optical modes with the 

mechanical breathing mode. Optical energy at an 

input wavelength aligned with one of the optical 

modes is transferred to an output wavelength 

aligned with a second optical mode. This is 

accomplished through the interaction with the 

mechanical system, which serves as a bridge to link 

the two optical modes together. The researchers 

demonstrated that they can upconvert and 

downconvert signals over an optical wavelength 

span of 300 nm, between the 1300 nm and 980 

nm wavelength bands that are frequently used 

in telecommunications. They believe that even 

wider ranges of wavelength conversion should be 

possible using the same geometry. 

Future work will focus on improving the conversion 

efficiencies, which are currently limited to about 

20 % within the cavity and 0.5 % for the device as 

a whole. Reducing noise, including thermal noise, 

which is the dominant noise source in current 

devices, can enable operation with extremely 

weak input signals, potentially all the way down to 

the single photon states of light used in quantum 

information processing applications. 

Optical wavelength conversion mediated by radiation 

pressure interacts with a mechanical mode. (a) A 

scanning electron micrograph of a fabricated silicon 

nitride microdisk resonator. (b) Schematic showing 

wavelength conversion between optical “whispering 

gallery” modes at 1300 nm and 980 nm wavelengths. 

The conversion is achieved through interaction with 

a mechanical breathing mode that serves as a bridge 

between the two optical modes. 

Electromagnetically induced transparency and wideband wavelength conversion in silicon nitride microdisk optomechanical resonators, Y. Liu, M. Davanço, V. Aksyuk, and K. Srinivasan, Physical Review Letters 110, 

223603 (2013). 

6 
 

 

THE REINS OF CASIMIR: ENGINEERED NANOSTRUCTURES COULD OFFER 

WAY TO CONTROL QUANTUM EFFECT ONCE MYSTERY IS SOLVED 

You might think that a pair of parallel plates 

hanging motionless in a vacuum just a fraction 

of a micrometer away from each other would be 

like strangers passing in the night—so close 

but destined never to meet. Thanks to quantum 

mechanics, you would be wrong. 

Scientists working to engineer nanoscale 

machines know this only too well as they have to 

grapple with quantum forces and all the weirdness 

that comes with them. These quantum forces, 

most notably the Casimir effect, can play havoc 

if you need to keep closely spaced surfaces from 

coming together. 

Controlling these effects may also be necessary 

for making small mechanical parts that never 

stick to each other, for building certain types of 

quantum computers, and for studying gravity at 

the microscale. 

Now, a large collaborative research group 

involving scientists from a number of federal labs, 

including the CNST, and major universities, has 

observed that these sticky effects can be increased 

or lessened by patterning one of the surfaces with 

nanoscale structures. The discovery, described in 

Nature Communications, opens a new path for 

tuning these effects. 

But as often happens with quantum phenomena, 

the work raises new questions even as it 

answers others. 

One of the insights of quantum mechanics is 

that no space, not even outer space, is ever truly 

empty. It’s full of energy in the form of quantum 

fluctuations, including fluctuating electromagnetic 

fields that seemingly come from nowhere and 

disappear just as fast. 

Some of this energy, however, just isn’t able to 

“fit” in the sub-micrometer space between a pair 

of electromechanical contacts. More energy on 

the outside than on the inside results in a kind of 

“pressure” called the Casimir force, which can be 

powerful enough to push the contacts together 

and stick. 

Researchers measured the Casimir attraction between a metallic grating and a gold coated sphere. They found that the 

attraction between the nanostructured surface and the sphere decreased much more rapidly than theory predicts when the two 

surfaces were moved away from each other. 

Prevailing theory does a good job describing the 

Casimir force between featureless, flat surfaces 

and even between most smoothly curved surfaces. 

However, according to NIST researcher and coauthor of the paper, Vladimir Aksyuk, existing 

theory fails to predict the interactions they 

observed in their experiment.

 “In our experiment, we measured the Casimir 

attraction between a gold-coated sphere and 

planar gold surfaces patterned with rows of 

periodic flat-topped ridges, each less than 100 

nanometers across, separated by somewhat wider 

gaps with deep sheer-walled sides,” says Aksyuk. 

“We wanted to see how a nanostructured metallic 

surface would affect the Casimir interaction, which 

had never been attempted with a metal surface 

before. Naturally, we expected that there would be 

reduced attraction between our grooved surface 

and the sphere regardless of the distance between 

them because the top of the grooved surface 

presents less total surface area and less material. 

However, we knew the Casimir force’s dependence 

on the surface shape is not that simple.” 

Indeed, what they found was more complicated. 

According to Aksyuk, when they increased the 

separation between the surface of the sphere 

and the grooved surface, the researchers found 

that the Casimir attraction decreased much more 

quickly than expected. When they moved the 

sphere farther away, the force fell by a factor 

of two below the theoretically predicted value. 

When they moved the sphere surface close to 

the ridge tops, the attraction per unit of ridge top 

surface area increased. 

“Theory can account for the stronger attraction, 

but not for the too-rapid weakening of the force 

with increased separation,” says Aksyuk. “So 

this is new territory, and the physics community 

is going to need to come up with a new model to 

describe it.” 

This work was performed in collaboration with 

scientists from Los Alamos National Laboratory; 

the University of Maryland, College Park; Argonne 

National Laboratory; and Indiana University – 

Purdue University Indianapolis. 

Strong Casimir force reduction through metallic surface nanostructuring, F. Intravaia, S. Koev, I. W. Jung, A. A. Talin, P. S. Davids, R. S. Decca, V. A. Aksyuk, D. A. R. Dalvit, and D. López, Nature Communications 4, (2013). 

7 
 

 

STIFFENING THE BACKBONE OF DNA NANOFIBERS
 

An international collaboration including 

researchers from the CNST and the 

Universidad San Francisco de Quito, Ecuador 

have fabricated a self-assembled nanofiber from 

a DNA building block that contains both duplex 

(two-stranded) and quadruplex (four-stranded) 

DNA. This work is a first step toward the creation 

of new structurally heterogeneous (quadruplex/ 

duplex), yet controllable, DNA-based materials 

exhibiting novel properties suitable for bottom-totop self-assembly for nanofabrication, including 

self-organization of both inorganic materials 

(nanoparticles) and molecular electronics 

components. 

The new nanofibers are constructed from duplex 

DNA precursors that first form quadruplex DNA in 

the presence of potassium ions and then connect 

together to form a fiber. DNA quadruplexes are 

unusual structures that can form from DNA 

sequences that are rich in the nucleotide guanine. 

Each strand in the duplex DNA precursor contains 

an internal run of eight guanines, which creates a 

region of guanine-guanine mismatches, plus one 

Top: Schematic showing association of two duplex 

precursors into a quadruplex fiber building block. The 

duplex regions of the building block are shown in red and 

blue; the quadruplex region is shown in gray. Bottom: 

Atomic force microscopy image of quadruplex DNA 

nanofibers. These fibers can be 2 μm or more in length. 

segment that extends past the duplex region 

to create a single-stranded overhang. When 

potassium ions are added, the duplex precursors 

self-assemble into quadruplex structures, and 

then into duplex/quadruplex fibers. These fibers were 

detected in bulk using electrospray mass spectrometry 

and gel electrophoresis. Single-molecule analysis 

using atomic force microscopy revealed fiber lengths 

ranging from 250 nm to 2000 nm. Because interaction 

between four strands of DNA takes place in some 

fiber segments, the final structures appear to be 

stiffer than DNA-based structures built from duplexonly subunits. This increased stiffness should lead 

to improved DNA patterning for nanotechnology 

applications. In contrast to DNA origami and DNA tile 

structures that are based solely on duplex DNA, the 

researchers believe that by varying the sequence of 

duplex and quadruplex subunits they ultimately will 

be able to create DNA building blocks that remain 

intact at temperatures ranging from room temperature 

to 100 oC. 

According to CNST Project Leader Veronika Szalai, 

this work will allow future integration with other 

programmable self-assembly methods such as 

DNA origami, as well as with other nanomaterial 

components such as quantum dots, to create new 

multi-functional biological-based nanomaterials. 

Synapsable quadruplex-mediated fibers, M. A. Mendez and V. A. Szalai, Nanoscale Research Letters 8, 210 (2013). 

DNA SIZE AND SHAPE UNEXPECTEDLY CONNECTED IN NANOFLUIDIC
 

CONFINEMENT 

Understanding the behavior of DNA in a fluid 

confined to a nanoscale space is a persistent 

challenge in polymer science and is increasingly 

important for engineering nanofluidic devices for 

manipulating and measuring DNA for forensic 

and healthcare applications. NIST researchers 

from the Material Measurement Laboratory, the 

Physical Measurement Laboratory, and the CNST 

have used a rigorous statistical analysis to study 

the size of single DNA molecules confined in 

nanofluidic slits between two surfaces and have 

discovered an unexpected result: changes in 

DNA size depend both on the local confinement 

conditions imposed externally by the slits and on 

the internal constraints due to the shape of the 

DNA backbone. 

The researchers had previously used fluorescence 

microscopy to make quantitative measurements 

of DNA size during the spontaneous transport of 

DNA molecules down a nanofluidic staircase of 

connected slits. Confined to the shallowest slit at 

the top of the staircase, a DNA molecule diffuses 

across that slit. The DNA tends to step down to 

the next deeper slit when it reaches the edge. 

The transport of the DNA to the bottom of the 

staircase ends as the molecule is trapped in the 

deepest slit. The slit depths, ranging from just a 

few nanometers to several hundred nanometers, 

are shallow enough to change the size of a DNA 

molecule. The researchers noticed that as the 

nanofluidic slits get deeper around the critical 

length scale at which the DNA backbone can 

be considered as stiff, the DNA molecules 

unexpectedly seem to contract either more 

gradually or more abruptly, depending on 

whether the DNA backbone is linear (openended) or circular (closed-loop). 

By applying a statistical analysis to their 

previous measurements, the researchers have 

confirmed their surprising observation that the 

size of the circular DNA changes more abruptly 

with slit depth than the linear DNA. However, 

their analysis does not preclude the possibility 

that a similar transition occurs for linear DNA in 

shallower slits. The researchers envision that 

their new methodology and unexpected results 

will motivate further research to clarify the many 

physical and chemical phenomena relevant to 

The apparent size of a circular DNA molecule confined to a 

nanofluidic slit, relative to its unconfined size, is plotted as a 

function of slit depth. Around a critical length scale related 

to the stiffness of the DNA backbone, the size of circular 

DNA changes more abruptly (green solid line) than gradually 

(magenta dash line). Fluorescence micrographs show circular 

DNA molecules confined to shallower and deeper slits. 

the behavior of DNA confined to nanoscale spaces. In 

addition, nanofluidic devices could be used to separate 

or otherwise manipulate mixtures of DNA molecules 

based on their shape, as seemingly small changes in 

confinement around a critical length scale would have 

unexpectedly large effects on DNA behavior. 

A localized transition in the size variation of circular DNA in nanofluidic slitlike confinement, E. A. Strychalski, S. M. Stavis, and J. Geist, AIP Advances 3, 042115 (2013). 

8 
 

 

 

 

 

 

 

RESEARCHERS PROBE THE PROPERTIES OF NOVEL TOPOLOGICAL INSULATORS
 

Researchers from the CNST, the University of 

Maryland, and Seoul National University, 

Korea have achieved electric-field control of the 

energy levels at the surface of two potentially 

important materials, bismuth selenide (Bi2

Se3) and 

antimony telluride (Sb2

Te3). These materials are 

topological insulators, which are hybrid materials 

that are electrical insulators in their interiors 

but are exotic, graphene-like conductors at their 

surfaces. 

Understanding how to use electric fields to 

control the energy levels at the surfaces of such 

topological insulators could make these materials 

extremely promising for a variety of electronic 

applications. This type of electric field control 

mirrors the gating used to turn on and off the field 

effect transistors found in countless everyday 

electronic devices. Achieving this control while 

characterizing the material’s surface directly with 

scanning tunneling microscopy—in principle an 

ideal method to observe the effects of electric 

fields—has been particularly challenging, 

because the typical processing needed to create 

the required electrodes damages the surface 

to be studied. The CNST researchers and their 

collaborators have overcome this challenge by 

developing high temperature sample holders that 

contain both the gating electrode and a dielectric 

upon which topological insulator films can be 

grown in-situ using molecular-beam epitaxy. The 

specially fabricated samples holders, made in the 

CNST NanoFab, incorporate strontium titanate 

substrates with pre-patterned electrodes, allowing 

pristine films to be deposited after the electrode 

fabrication process. 

Using the gating electrode to apply an electric field, 

the researchers are able to tune the doping of the 

top surfaces of the Bi2

Se3 and Sb2Te3 topological 

insulator devices in order to vary their surface 

energy levels. In a particularly noteworthy result, 

the gating measurements indicate that for ultra-thin 

Sb2

Te3 it may be possible to reversibly change the 

material from an ordinary insulator to a topological 

Scanning tunneling microscopy topographic image of a 

bismuth selenide film grown by molecular-beam epitaxy on 

a strontium titanate substrate. Terraces with thicknesses 

between 2 and 5 atomic layers can be found on the 

same film. 

insulator and thereby switch “on and off” 

special properties that can exist at the thin 

film boundaries that may be useful in electrical 

device applications. 

Scanning tunneling microscopy of gate tunable topological insulator Bi2Se3 thin films, T. Zhang, N. Levy, J. Ha, Y. Kuk, and J. A. Stroscio, Physical Review B 87, 115410 (2013).
 

Electric field tuning of the surface band structure of topological insulator Sb2

Te3 thin films, T. Zhang, J. Ha, N. Levy, Y. Kuk, and J. Stroscio, Physical Review Letters 111, 056803 (2013).
 

U.S. AND KOREA COLLABORATE ON GRAPHENE RESEARCH
 

Researchers from the CNST and the Republic 

of Korea’s national metrology institute— 

the Korea Research Institute of Standards and 

Science (KRISS)—have recently developed a 

unique nanoscale measurement technique and 

used it to observe structural disorder in graphene 

that is fabricated on a silicon carbide substrate. 

Graphene, a material made of carbon in a one 

atom-thick sheet, has promising applications in 

areas ranging from flexible displays to high speed 

transistors; but such applications will require 

new methods for large area fabrication and for 

detecting underlying fabrication-related structural 

defects. 

The team’s approach relies on local thermopower 

measurements that use heat transfer from 

a scanning probe tip to the sample surface, 

thereby allowing extremely sensitive imaging 

of nanometer scale disorder in graphene layers. 

The technique enables the direct observation 

Thermopower image of epitaxial graphene. The three distinct 

indexed regions correspond to (I) monolayer graphene, (II) 

bilayer graphene, and (III) trilayer graphene. 

of nanoscale structural changes in a material by 

measuring changes in the heat transfer associated 

with modifications in a material’s local electronic 

properties. Through such local thermopower 

measurements, the team discovered a boundary 

between two regions of the graphene layer that 

have different crystal orientations. The creation 

of these different regions results from two stacked 

graphene layers being rotated or translated with 

respect to each other. 

The researchers believe these initial measurements 

demonstrate a new scanning probe measurement 

technique that will have significant applications in 

developing technologies based on graphene and 

other emerging electrical materials. 

The team includes researchers from the CNST, the 

KRISS, the Korea Advanced Institute of Science 

and Technology (KAIST), the Korea Research 

Institute of Chemical Technology, Pohang 

University of Science and Technology, and Seoul 

National University. 

Thermoelectric imaging of structural disorder in epitaxial graphene, S. Cho, S. D. Kang, W. Kim, E.-S. Lee, S.-J. Woo, K.-J. Kong, I. Kim, H.-D. Kim, T. Zhang, J. A. Stroscio, Y.-H. Kim, and H.-K. Lyeo, Nature Materials 12, 

913–918 (2013) 

9 
 

 

 

 

 

A STEP TOWARDS ENERGY-EFFICIENT VOLTAGE CONTROL OF MAGNETIC
 

DEVICES
 

Researchers from the CNST and the University 

of California, Berkeley have discovered a 

way to create simultaneous images of both the 

magnetic and the electric domain structures in 

ferromagnetic/ferroelectric multilayer materials. 

In a ferroelectric material, the polarization, or 

direction, of the internal electric field can be 

controlled by applying a voltage across the film; 

in a ferromagnetic material, current-induced 

magnetic fields are usually used to control the 

magnetization direction. By combining these 

two types of materials, it is possible to create 

low-power magnetic devices, including memory 

that can be controlled by electric fields (applied 

voltage) instead of less energy-efficient magnetic 

fields (applied current). Measuring how the 

magnetization in a ferromagnet realigns in 

response to changes in the electric polarization 

of an adjacent ferroelectric is an important step 

towards making such low-power devices possible. 

The researchers used scanning electron 

microscopy with polarization analysis (SEMPA) 

to directly image the magnetization direction in 

thin ferromagnetic films made of cobalt-iron that 

were grown on thicker ferroelectric substrates 

made of bismuth ferrite. While taking the SEMPA 

measurements, which use low-energy secondary 

electrons to visualize the magnetization in the thin 

cobalt-iron film, they also imaged the ferroelectric 

domains using a separate detector to measure 

higher-energy backscattered electrons from the 

buried bismuth ferrite. Because these electrons 

are much higher in energy, they can exit from 

deeper in the sample, allowing the ferroelectric to 

be imaged beneath the ferromagnetic film. 

The SEMPA and backscattered electron images 

provided new information about the coupling 

between the two layers that occurs at their 

interface. Although bismuth ferrite is primarily 

ferroelectric, it also has antiferromagnetic 

properties (it has no net magnetization). However, 

when a ferromagnetic film is deposited on top of 

Scanning electron microscope images of a cobalt film grown on a bismuth ferrite substrate. The color SEMPA image shows the 

direction of the magnetization in the ferromagnet, and the black and white backscattered electron image shows the domain 

structure of the underlying ferroelectric. The two images were acquired simultaneously, allowing quantitative measurements 

of the ferromagnetic/ferroelectric correlations. 

a bismuth ferrite film, the bismuth ferrite becomes 

slightly ferromagnetic and its induced magnetization 

changes along with the adjacent cobalt-iron’s 

magnetization. It has been theorized that when the 

ferroelectric polarization in the bismuth ferrite is 

switched by an electric field, the small ferromagnetic 

component also switches and in turn changes 

the direction of the cobalt-iron magnetization. 

The SEMPA and backscattered electron images 

showed that the local, nanoscale direction of the 

magnetization of the cobalt-iron film nearly aligns 

with both the interfacial direction of the ferroelectric 

polarization and with the induced ferromagnetism of 

the bismuth ferrite. By modeling the deviation 

from perfect alignment, the researchers were 

able to infer the strength of the interaction at the 

interface between the two materials. 

Because these initial experiments have been 

promising, the researchers plan to add electrical 

contacts to small patterned cobalt-iron elements 

and to use SEMPA to conclusively observe 

whether their magnetization can be changed 

electrically. 

Interfacial coupling in multiferroic/ferromagnet heterostructures, M. Trassin, J. D. Clarkson, S. R. Bowden, J. Liu, J. T. Heron, R. J. Paull, E. Arenholz, D. T. Pierce, and J. Unguris, Physical Review B 87, 

134426 (2013). 

10 
 

 

NEW NANOSCALE IMAGING METHOD FINDS APPLICATION IN PLASMONICS
 

Researchers from the CNST and the University 

of Maryland have shown how to make 

nanoscale measurements of critical properties of 

plasmonic nanomaterials—specially engineered 

nano-structures that modify the interaction of light 

and matter for a variety of applications, including 

sensors, cloaking (invisibility), photovoltaics, and 

therapeutics. 

Their technique is one of the few that allows 

researchers to make actual physical measurements 

of these materials at the nanoscale without 

affecting the nanomaterial’s function. 

Plasmonic nanomaterials are made of specially 

engineered nanoscale structures that can enhance 

the interaction between light and matter. The 

shape and size of these nanostructures can be 

adjusted to tune these interactions. Theoretical 

calculations are frequently used to understand 

and predict the optical properties of plasmonic 

nanomaterials, but few experimental techniques 

are available to study them in detail. Researchers 

need to be able to measure the optical properties 

of individual structures and how each interacts 

with the surrounding material directly in a way that 

doesn’t affect how the structure functions. 

“We want to maximize the sensitivity of these 

resonator arrays and study their properties,” says 

lead researcher Andrea Centrone. “In order to do 

that, we needed an experimental technique that 

we could use to verify theory and to understand 

the influence of nanofabrication defects that are 

typically found in real samples. Our technique 

has the advantage of being extremely sensitive 

spatially and chemically, and the results are 

straightforward to interpret.” 

The research team turned to photothermal induced 

resonance (PTIR), an emerging chemically-specific 

materials analysis technique, and showed it 

can be used to image the response of plasmonic 

nanomaterials excited by infrared (IR) light with 

nanometer-scale resolution. 

The team used PTIR to image the absorbed 

energy in ring-shaped plasmonic resonators. The 

nanoscale resonators focus the incoming IR light 

Infrared laser light (purple) from below a sample (blue) excites ring shaped nanoscale plasmonic resonator structures (gold). Hot 

spots (white) form in the rings’ gaps. In these hot spots, infrared absorption is enhanced, allowing for more sensitive chemical 

recognition. A scanning AFM tip detects the expansion of the underlying material in response to absorption of infrared light. 

within the rings’ gaps to create “hot spots” where 

the light absorption is enhanced, which makes 

for more sensitive chemical identification. For the 

first time, the researchers precisely quantified 

the absorption in the hot spots with nanoscale 

resolution and showed that for the samples under 

investigation, it is approximately 30 times greater 

than areas away from the resonators. 

The researchers also showed that plasmonic 

materials can be used to increase the sensitivity of 

IR and PTIR spectroscopy for chemical analysis by 

enhancing the local light intensity, and thereby, the 

spectroscopic signal. 

Their work further demonstrated the versatility 

of PTIR as a measurement tool that allows 

simultaneous measurement of a nanomaterial’s 

shape, size, and chemical composition—the three 

characteristics that determine a nanomaterial’s 

properties. Unlike many other methods for 

probing materials at the nanoscale, PTIR doesn’t 

interfere with the material under investigation; 

it doesn’t require the researcher to have prior 

knowledge about the material’s optical properties 

or geometry; and it returns data that is more easily 

interpretable than other techniques that require 

separating the response of the sample from the 

response of the probe. 

Nanoscale imaging of plasmonic hot spots and dark modes with the photothermal-induced resonance technique, B. Lahiri, G. Holland, V. Aksyuk, and A. Centrone, Nano Letters 13, 3218–3224 (2013). 

11 
 

 

 

 

 

 

 

 

NEW GRAYSCALE TECHNIQUE OPENS A THIRD DIMENSION FOR
 

NANOSCALE LITHOGRAPHY
 

Engineers from the CNST have developed a 

new technique for fabricating high aspect ratio 

three-dimensional (3D) nanostructures over large 

device areas using a combination of electron beam 

(e-beam) lithography, photolithography, and resist 

spray coating. While it has long been possible to 

make complicated 3D structures with many mask 

layers or expensive grayscale masks, the new 

technique enables researchers to etch trenches 

and other high aspect ratio structures with 

nanometer scale features without using masks and 

in only two process stages. 

The fabrication of 3D semiconductor and dielectric 

structures that are patterned by exposing resist 

with varying intensity grayscale gradients has 

been essential to a broad range of applications 

such as digital lenses, micro-electromechanical 

systems, and fluidic medical devices. 

Unlike devices that rely on conventional masks, 

which have areas that simply transmit or block light 

to form a pattern, the fabrication of these devices 

has typically relied on 3D grayscale masks which 

have varying levels of transparency and depend 

on the use of proprietary materials. Because the 

chemistry is proprietary and because the masks are 

prepared using complicated processes best suited 

to small surface areas, they are often prohibitively 

expensive. The next generation of these devices 

requires lower costs, larger surface areas, and 

ever-smaller feature sizes. 

The researchers’ new approach capitalizes on the 

high throughput capability of photolithography to 

generate large area grayscale structures with large 

processing flexibility and the ability of e-beam 

lithography to add grayscale features smaller than 

200 nm. The first phase of this mix-and-match 

approach is to pattern a layer of photoresist by 

exposing it with a focused laser beam. By locally 

modulating the intensity of the light to form a 

grayscale gradient, varying levels of photoreaction 

in the photoresist are generated. After the sample 

is immersed in the developer solution, material 

is dissolved in areas corresponding to the degree 

Scanning electron micrograph (SEM) showing a top-view along with an SEM (inset) showing a cross-sectional view of grayscale 

structures fabricated using a combination of e-beam lithography, photolithography, and resist spray coating. The superimposed 

schematic illustrates e-beam direct writing of nanoscale vertical staircases (SEM inset) on a substrate with microscale 

grayscale topography. The initial grayscale patterns were generated on a laserwriter. After reactive ion beam etching, the 

patterns were simultaneously written into 2 μm, 0.5 μm, and 30 μm deep features. 

of induced photoreaction, leaving the photoresist 

layer with varying thicknesses matching the initial 

exposure pattern. 

The sample is exposed to a deep reactive ion 

etch (DRIE) which removes substrate material at 

varying depths that depend on the thickness of the 

photoresist, transferring the 3D photoresist pattern 

vertically into the substrate to form deep grayscale 

micro-structures. The second phase applies similar 

processing steps but with feature sizes ten times 

smaller. First, a high pressure e-beam resist spray 

coating is applied to obtain conformal coverage of 

the high-aspect ratio topography produced in the first 

phase. Then, by manipulating a high-energy e-beam 

with nanometer-scale resolution, patterned grayscale 

step heights are directly written in the e-beam resist 

in different locations. Finally, the resist is developed 

and the sample is exposed to DRIE as it was in 

the first step. 

The two stage process results in a vertical feature 

sizes of 45 ± 6 nm within a substrate structure 

that varies from 2 μm to 30 μm deep and with 

horizontal feature sizes of 100 nm to 200 nm and 

an overall pattern size potentially as large as a 

whole wafer. 

CNST NanoFab Process Engineer Liya Yu 

anticipates that the ability to fabricate high 

aspect-ratio grayscale nanostructures will expand 

the practical applications of grayscale lithography 

and dramatically widen the range of device 

structures available to device designers. 

The evaluation of photo/e-beam complementary grayscale lithography for high topography 3D structure, L. Yu, R. J. Kasica, R. N. Newby, L. Chen, and V. K. Luciani, Proceedings of SPIE 8682, 868212 (2013). 

12 
 

 

 

 

 

 

 

 

 

 

NANOFAB ADDS NEW HIGH RESOLUTION X-RAY DIFFRACTION SYSTEM
 

The NanoFab has added a new Rigaku 

SMARTLAB X-Ray Diffractometer (XRD), which 

is designed for completely automated analysis of 

thin films, nanomaterials, and powders. This state 

of the art XRD can be used to determine the crystal 

structure and identify the phases of thin films 

and bulk materials. It is easy to use and is fully 

equipped with modules for performing a variety of 

advanced X-ray diffraction measurements such as 

X-ray reflectivity, grazing incidence diffraction, outof-plane and in-plane diffraction, and small angle 

X-ray scattering (SAXS). 

The system allows users to perform the following 

measurements: X-ray reflectivity measurements 

to determine film thickness and roughness with 

nanometer precision; X-ray powder diffraction 

to identify the phase of powders and thick films; 

pole figures for texture or orientation analysis; 

reciprocal space maps for information on epitaxial 

thin films; and rocking curves to study dislocation 

density, misalignment of crystal planes, and 

inhomogeneity of thin films. The X-ray system is 

also equipped with a small angle X-ray scattering 

attachment for the determination of pore sizes or 

particle sizes of samples. 

This XRD system is extremely versatile, allowing 

samples to be measured under a range of controlled 

environments, including fixed room temperature or 

while they are heated up to 1100 °C in vacuum, in 

air, or in inert gasses. 

The NanoFab’s new Rigaku SMARTLAB X-Ray Diffractometer 

(shown above with NanoFab Process Engineer Kerry Siebein) is 

designed for completely automated crystal structure and phase 

analysis of thin films, nanomaterials, and powders. 

The system includes a high intensity 9 kW rotating 

anode X-ray generator that allows for extremely 

fast measurements. According to NanoFab 

Process Engineer Kerry Siebein, “X-ray reflectivity 

measurements that would take hours on other 

systems can now be completed in fifteen to twenty 

minutes, and reciprocal space maps that would take 

days can now be completed in a few hours.” 

The XRD has a user-friendly computer controlled 

alignment system and a fully automated optical 

system. It is now available to users and can be 

reserved through the NEMO system. 

For more information, contact Kerry Siebein, 

301-975-8458, kerry.siebein@nist.gov. 

Reciprocal space map of NIST standard reference material 

2000, a 50 nm-thick silicon-germanium epitaxial layer deposited 

on a silicon substrate, courtesy of Donald Windover, Material 

Measurement Laboratory. The intense peak is caused by 

diffraction from the substrate wafer and the oscillation pattern 

is used to determine epitaxial film thickness. The orientation 

and peak shapes of the oscillations provide information about 

epitaxial film quality, wafer cut alignment, and dislocation 

densities. The NanoFab XRD took 6.7 hours to generate 

this intensity map, a factor of 10 to 20 less time than using a 

conventional sealed-tube system. 

CNST DEVELOPS AND DEPLOYS NEW NANOFAB MANAGEMENT SYSTEM
 

The CNST has deployed a new laboratory 

equipment management system which it 

developed from the ground up. The web-based 

program, known as the NanoFab Equipment 

Management & Operations (NEMO) system, allows 

onsite NanoFab users to make tool reservations, 

controls access to tools in the NanoFab, and 

streamlines logistics and communication. 

NEMO provides onsite users an experience that is 

simple, intuitive, and quick. Its click-and-drag web 

interface gives users the ability to easily create 

and modify tool reservations. To ensure that 

tools are ready when users arrive, the program 

automatically sends configuration information to 

The program is a major update to the 

Center’s NanoFab computing infrastructure, 

and replaces the OpenCoral laboratory 

management program. 

The CNST plans to continuously improve 

NEMO in order to provide additional 

features and services to NanoFab users. 

According to CNST IT specialist Dylan 

Klomparens, who created the system, 

in addition to equipment reservations, 

NanoFab users will soon have the ability to 

reserve and use CAD software licensed by 

the CNST at cost-effective hourly rates. 

NEMO’s tool reservation calendar allows onsite NanoFab users to 

make and change reservations with a simple click-and-drag. 

the appropriate NanoFab staff members for tools To provide us with feedback about 

that need to be configured prior to use. Users can NEMO or learn more about it, please 

easily view who is in the NanoFab and which tools contact the NanoFab User Office, 

are available. nanofabuseroffice@nist.gov. 

13 
 

 

STEVE BLANKENSHIP WINS AVS GEORGE T. HANYO AWARD FOR 

OUTSTANDING PERFORMANCE IN TECHNICAL SUPPORT OF RESEARCH 

Steve Blankenship, an Instrumentation 

Specialist in the CNST, has been awarded 

the 2013 George T. Hanyo Award by the AVS 

“for outstanding contributions to the scanning 

tunneling microscopy user facilities and other 

laboratories at the Center for Nanoscale Science 

and Technology at the National Institute of 

Standards and Technology.” 

The award, established in 1996 by the Kurt J. 

Lesker Company in the memory of George T. 

Hanyo, a highly skilled, long-time employee of 

the company, recognizes outstanding performance 

in technical support of research or development 

in areas of interest to the AVS. The award is 

intended for a technical support staff member who 

is typically mentioned in the “Acknowledgements” 

sections of published papers but, with the possible 

exception of papers describing new apparatus or 

procedures, is rarely an author or co-author. 

Steve was presented with the award on October 

30, 2013 at the AVS 60th International Symposium 

and Exhibition in Long Beach, California. 

Steve Blankenship holds the Hanyo award certificate at the 2013 AVS International Symposium and Exhibition. 

Left to right: John Russell, Jr. (Naval Research Laboratory, AVS Trustee), Blankenship, Susan Sinnott (University 

of Florida, AVS President). 

NANOFAB SCHEDULE FOR THE WINTER HOLIDAY PERIOD 

When the NanoFab is closed, after-hours access using the buddy system is available with advance approval. 

FALL IN THE NANOFAB 

Composite multi-focal scanning electron micrograph of DRIE-etched silicon taken
 

using the NanoFab’s Helios 650 Dual Beam SEM/FIB by CNST Process Engineer Joshua
 

Schumacher. With false color added, the image, titled “Happy Little Si-Etched Trees” as
 

an homage to artist Bob Ross, captures the colors of fall at the CNST and won third place
 

in the 8th Annual FIB/DB User Club Meeting image competition held at the FEI NanoPort
 

in Hillsboro, Oregon in October, 2012.
 

14 
 

 

 

 

RESEARCHERS INTRODUCE BLIND STUDENTS TO NANOSCALE SCIENCE
 

I

n July 2013, 45 blind and visually impaired 

high school students from around the country 

gathered at Towson University for a weeklong 

event designed to expose them to science careers 

long believed to be impossible for the blind. 

Twenty of those students participated in an exciting 

educational program on nanoscale science led by 

CNST Project Leader Vladimir Aksyuk, who has 

participated in this event for the last three years, 

and CNST/University of Maryland Postdoctoral 

Researcher Kevin Twedt, who is visually impaired. 

During six hours of hands-on activities spread 

over two days, the students learned the basics of 

size and scale, the metric system, and received 

an introduction to the nanoscale. They then 

learned the techniques scientists use to create 

and measure nanoscale structures. By probing 

canes against floor models of different shapes 

and sizes, they were exposed to how an atomic 

force microscope probe senses topographic 

changes on a surface. Using plastic models, they 

explored the structural relationships between 

carbon atoms forming either planar graphene or 

three-dimensional carbon nanotubes. Finally, 

by scanning a laser pointer across black shapes 

on white paper and using a photodiode with an 

Physicists Kevin Twedt (left), who is visually impaired, and Vladimir Aksyuk (right) led a two day educational program to introduce 

a group of blind and visually impaired high school students to nanotechnology. 

audio output that got louder in white regions and 

quieter in dark regions, the students learned how 

a scanning electron microscope creates images by 

scanning a beam of electrons across a surface. 

“Most of these students had never really 

considered careers in science or knew that they 

are possible for blind people,” says Twedt, who 

has had 20/200 vision since birth. “In a few days, 

the students gained an appreciation for the work 

scientists do and perhaps some will consider 

going into science later on.” 

The science, technology, engineering, and math 

(STEM) program, known as the STEM-X program 

was sponsored by National Federation of the 

Blind, under the auspices of its National Center for 

Blind Youth in Science. 

SUMMER STUDENTS WORK WITH LEADING RESEARCHERS AT THE CNST
 

CNST welcomed its 2013 class of The 

summer student researchers. Nine Summer 

Undergraduate Research Fellowship (SURF) 

students, one returning CNST/UMD Undergraduate 

Researcher, and six High School students learned 

about the latest nanotechnology fabrication and 

measurement techniques. They participated in 

a wide variety of research projects ranging from 

developing a data acquisition system for highspatial resolution spectroscopy in photovoltaic 

devices to simulating carbon nanotube growth 

under different synthesis conditions. The SURF 

program is sponsored by NIST and the National 

Science Foundation. 

Summer Undergraduate Researchers 

Noah (Adam) Bern, Cornell University 

Philip Trettenero, University of Illinois at 

Urbana-Champaign 

Michael Briggs, SUNY, University at Albany 

Osama Khalil, Arizona State University 

Jonathan (Yoni) Mehlman, Yeshiva University 

Timothy Straley, Colorado School of Mines 

The CNST SURF students were among 187 

at NIST attending seminars, going on lab 

tours, and presenting their work at an endof-summer colloquium. Left to right, top row: 

Blankenau, Briggs, Trettenero, Mehlman, 

and Bern. Bottom row: Khalil, Tolstaya, 

Sytwu, and Straley. 

Summer Undergraduate Researchers 

Katherine Sytwu, Rutgers, The State University 

of New Jersey 

Ekaterina (Kate) Tolstaya, University of Maryland 

Brian Blankenau, Kansas State University 

CNST/UMD Undergraduate Researcher 

Cory Latham, Virginia Polytechnic Institute and 

State University 

High School Researchers 

Trevin Gandhi, Loudoun County Academy of Science, MD 

Andrew T. Wang, Winston Churchill High School, MD 

Elizabeth McMichael, Poolesville High School, MD 

Lisa Shimomoto, Poolesville High School, MD 

Andrew Z. Wang, Poolesville High School, MD 

Ryan Wong, Poolesville High School, MD 

15 
 

 

CENTER FOR NANOSCALE 

SCIENCE AND TECHNOLOGY 

The CNST is a national user facility purposely designed to accelerate 

innovation in nanotechnology-based commerce. Its mission is to operate a 

national, shared resource for nanoscale fabrication and measurement and 

develop innovative nanoscale measurement and fabrication capabilities to 

support researchers from industry, academia, NIST, and other government 

agencies in advancing nanoscale technology from discovery to production. 

The Center, located in the Advanced Measurement Laboratory Complex 

on NIST’s Gaithersburg, MD campus, disseminates new nanoscale 

measurement methods by incorporating them into facility operations, 

collaborating and partnering with others, and providing international 

leadership in nanotechnology. 

If you would like to subscribe to this newsletter, go to 

http://www.nist.gov/cnst/newsletters.cfm, enter your e-mail address, 

and follow the on-screen instructions. Alternately, you may request 

a subscription via email or phone. 

SUPPORTING THE 

DEVELOPMENT OF 

NANOTECHNOLOGY 

FROM DISCOVERY TO 

PRODUCTION 

Center for Nanoscale Science and Technology 

National Institute of Standards and Technology 

100 Bureau Drive, MS 6200 

Gaithersburg, MD 20899-6200 

Phone: 301-975-8001 

E-mail: cnst@nist.gov 

CNST RELEASES NEW BROCHURE 

August, the CNST released a new In 

CNST Brochure. In addition to providing 

an overview of the CNST, it features 

separate sections highlighting the 

resources available in the NanoFab and 

the NanoLab. 

The brochure provides a detailed list of the 

commercial tools and processes available in the 

NanoFab at economic hourly rates, along with 

descriptions of the key capabilities available 2013 MATERIALS RESEARCH SOCIETY 

in each process area. It also describes the The brochure can be downloaded at FALL MEETING 

next generation of tools and processes under www.nist.gov/cnst/upload/CNST_brochure.pdf. HYNES CONVENTION CENTER 

development in the NanoLab, which are available To receive a hard copy, please email BOSTON, MASSACHUSETTS through collaboration with our multidisciplinary cnst@nist.gov with your request and mailing DECEMBER 1 – 6, 2013 research staff. address. 

CNST LAUNCHES UPDATED NANOFAB WEBSITE 

The CNST has released a major update to the single application, to be used by all applicants Over the coming months, the CNST will continue 

NanoFab website. The updated website (from both inside and outside NIST), includes a to improve the website, updating and enhancing 

includes significant new content describing how simplified format designed to efficiently collect the information provided about the tools and 

to apply for and work in the NanoFab, status only the information required for the CNST to processes available in the NanoFab. 

information and news, a FAQ, and a complete identify the project’s participants and evaluate the redesign of the site’s navigation. To provide us with feedback about the project’s technical feasibility and merit. In addition 

website, or to learn more about the NanoFab, Along with the new site, the NanoFab is to guidance provided on how to complete the 

please contact the NanoFab User Office, introducing a new NanoFab Project Application. application, a selection of fictional examples are 

nanofabuseroffice@nist.gov. The simple application process is designed to get available that illustrate the nature and scope of the 

researchers into the NanoFab in a few weeks. The information required. 

WWW.NIST.GOV/CNST 131113