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Vibration Isolation News is designed to keep our customers and friends up to date on the latest products and applications designed to facilitate better measurements and improved nanomanufacturing. We are an OEM supplier to leading manufacturers of scanning probe microscopes, micro-hardness testers and other sensitive instruments, and we have users at more than 200 leading universities and private and government laboratories in 35 countries.
1. Minus K Selected by NASA for JWST Testing
2. Featured Application: Brain Waves at Georgetown Univeristy
3. Featured Product: BM-4 Used by hundreds of customers
4. Another Enabling Application: Improving AFM Reliability at Arizona State University
6. Our latest Ad
5. Upcoming Nanotechnology Meetings and Webinars
7. Your comments and suggestions
are proud that our negative stiffness technology is used
by some of the most quality conscious organizations in
the world. The scientists and engineers who have selected
Minus K products have done so because their work requires
the finest vibration isolation.
After considering many alternatives, ITT Space Systems, LLC, subcontractor to Northrop Grumman Corporation (NYSE:NOC), selected Minus K to provide vibration isolators for the ground testing of the new James Webb Space Telescope (JWST) at the Johnson Space Center (JSC). The JWST will be placed in a vacuum chamber at the Johnson Space Center and supported by a set of custom Minus K vibration isolators.
The James Webb Space Telescope is a large aperture infrared space telescope currently planned to be launched in 2014 from Kourou, French Guiana aboard an Ariane 5 launch vehicle. JWST is designated to succeed the Hubble Space Telescope (HST).
A major factor in selecting Minus K is the ability to not only isolate vibrations vertically, but also horizontally at less than 1 Hz.
The full story can be found at: http://www.jwst.nasa.gov/
dye and optical recording techniques are giving neuroscientists
at Georgetown University's Department of Physiology
and Biophysics a new means for figuring out how the
Professor Jian-Young Wu and his colleagues are conducting research on waves of neuronal activity. They visualize wave-like patterns in the brain cortex using a new method called voltage-sensitive dye imaging. The dye binds to the membrane of neurons and changes color when electrical potential changes on the membrane of active neurons. The neuronal sample is derived from slices of rat neocortex.
The neocortex is the outer layer of the cerebral hemispheres in the brain of mammals. Made up of six layers, it is involved in higher functions such as sensory perception, generation of motor commands and, in humans, language.
The neurons of the neocortex are arranged in vertical structures called neocortical columns. These are patches of the neocortex with a diameter of about 0.5 mm and a depth of 2 mm. Each column typically responds to a sensory stimulus representing a certain body part, or region of sound or vision. In the human neocortex, there are believed to be about a half-million of these columns, each of which contains approximately 60,000 neurons.
The neocortex can be viewed as a huge web, consisting of billions to trillions of neurons and hundreds of trillions of interconnections. While individual neurons are too simple to have intelligence, the collective behavior of the billions of interneuronal interactions occurring each second can be highly intelligent.
Traditionally, scientists have studied brain activity by placing a few electrodes in the brain and measuring the electrical signals of the neurons close to the electrodes. This method is workable for understanding the function of the cortex and interactions between individual neurons, but it is not suitable for studying the emerging properties of the nervous system.
"It is like viewing a few pixels on a television screen and trying to figure out the story," explains Wu. "Now, with optical methods and voltage-sensitive dyes, we can visualize the activation in a large area of the neocortex when the brain is processing sensory information, similar to watching the whole television screen."
"Voltage-sensitive dye is a compound that stains neuronal membrane and changes its color when the neuron is excited," continues Wu. "This allows us to visualize population neuronal activity dynamically in the cortex. We study how individual neurons in the neocortex interact to generate population neuronal activities that underlie sensory and motor processing functions. Population activities are composed of the coordinated activity of billions of neurons. Currently, we study how oscillations and propagating waves can be generated by small ensembles of neocortical neurons."
Viewing the spatiotemporal patterns of neuronal population in the cortex is markedly different from recording individual neurons. Here the cortical activity is viewed as "population activity," which can be more complex than the linear addition of an individual neuron's activity. Voltage-sensitive dye and optical recording techniques give the neuroscientist new tools for figuring out how brain cortex works.
Wu's imaging team has uncovered spiraling wave patterns resembling little hurricanes in the brain. He believes that this hurricane-like spiral pattern is an emergent behavior of the network.
"A metrological hurricane is an emergent behavior of a large volume of air molecules," says Wu. "If you were to dissect a hurricane into individual air molecules you would not find any special process that generates a hurricane. Similarly, in the nervous system, spiral waves are an emergent process of the neuronal population and there might be no special cellular process attributed to spirals."
However, like a hurricane, spiral waves can be a powerful force. Their power is seen when it comes to organizing the activity of a neuronal population. Spirals generated in a small area can send out a powerful storm that invades large, normal brain areas and starts a seizure attack. This hypothesis means that epilepsy could be viewed not just as "mis-wiring" in the brain, but as an abnormal wave pattern that invades normal tissue.
Similarly, during cardiac fibrillation, spiral waves form in the heart emitting rotating and scroll waves in two and three dimensions. As a leading life-threatening situation, these rotating waves can kill the patient instantly as the pumping function of the heart is disrupted by the 5 to 10 Hz rotations, which drives chaotic and abnormally rapid cardiac contractions.
Wu believes that propagating waves are a basic pattern of cortical neuronal activity, and that these wave patterns may play an important role in initiating and organizing brain activity involving millions to billions of neurons. Studying the spatiotemporal patterns of neuronal population activity may provide insight into normal brain functions and pathological disorders. This research has the potential to help scientists understand abnormal waves that are generated in the brains of patients with epilepsy.
Since voltage-sensitive dye signals are small - a change of 0.1 to 1.0 percent of the illumination intensity - Wu's team uses a high-dynamic-range camera, photodiode array to detect the voltage- sensitive dye signals of the cortical activity. The photodiode array can resolve extremely small changes in light, usually one part of ten thousands. (Human eyes and ordinary digital cameras register light changes of one part to a hundred). Detecting such small signals requires an extreme isolation of vibration. The lab had to contend with low frequency vibrations from air conditioning equipment, people walking, and wind blowing against the building. Vibrations as low as 1 Hz were inhibiting the integrity of the images and data.
"At first, we used high quality air tables, but they were not adequate for isolating low frequency vibrations," says Wu. "We tried putting a second air table on top of the first one, but that still did not give us the isolation we needed. Then we tried an active, electronic system, but we were still spending much time fighting with floor vibrations. We were dealing with an unresolved vibration problem for many years."
The Georgetown lab eventually tested, and settled upon negative-stiffness mechanism vibration isolation systems from Minus K Technology, Inglewood, CA, (www.minusk.com) which enabled the lab to get vibration isolation down to a level of 1 Hz. This effectively cancelled out any vibration noise difficulties that were inhibiting image and data readings.
Within the past 10 years, Wu's team has documented a variety of waveforms (e.g., plane wave and spirals) in brain slices during artificially induced oscillations. Using neocortical slices and mathematic models they are studying the initiation of the waves and the factors that control their propagating direction and velocity.
The negative-stiffness vibration isolation system are also used by the lab in the development of optical imaging techniques such as imaging propagating waves in vivo, within intact brains. "This is technically difficult," says Wu. "Other imaging methods (MRI, PET or MEG) provide inadequate spatiotemporal resolution. Large scale neuronal activity is a hallmark of a living brain. We hope to visualize the waves in the cortex in vivo during sensory processes and in animals while behavioral and cognitive tasks are performed."
The full article can be found at: https://minusk.com/content/in-the-news/medical_design_june_2009.html
BM-4 is one of our most popular products. It is the most
cost effective bench top platform capable of 1/2 Hz performance
vertical and horizontal.
Applications have included the full spectrum from Scanning Probe Microscopes (AFM, STM, NSOM, etc) and Laser/Optical systems through neurosciences, electronics, and even audio reproduction.
Because Minus K products can be used under vacuum conditions and require no power or air for their operation, they have been used in applications ranging from ground tests of spacecraft to sensitive experiments where there can be no stray electromagnetic fields.
Minus K's BM-4 Bench Top Vibration Isolator
transmissibility curve with 1/2 Hz natural Frequency
|Load Capacities (approximate):
|0 - 25 lb : (0 - 11 kg)
|20 - 55 lb : (9 - 25 kg)
|50 - 105 lb : (23 - 48 kg)
|*Contact Minus K for custom payload ranges.
**For International Orders, A Handling Fee of 5% is Added.
- Vertical natural frequency of 1/2 Hz or less can be achieved over the entire load range.
- Horizontal natural frequency is load dependent. 1/2 Hz or less can be achieved at or near the nominal load.
isolators have resonant frequencies at 0.4 to 0.5 Hz, compared
to 2.3 Hz for pneumatic systems. They transmit less energy
from low-frequency vibrations to the payload than do pneumatic
systems, and maintain better isolation performance through
building frequencies to about 100 Hz.
AFM data reliability in nanoelectronics research,
Utilizing negative-stiffness vibration isolation
Excerpted from Electronic Products & Technology - September 2008
Products on Review
Arizona State University Nanostructures Research Group, led by ASU Regents' Professor and nanoelectronics pioneer, David K. Ferry, Ph.D., M.S.E.E., B.S.E.E., utilizes negative-stiffness vibration isolation technology to more efficiently eliminate ultra-low environmental frequencies and improve data set integrity in nanoelectronics AFM research.
not until Long after 1977 that the name nanoelectronics
came into use, but Dr. David K. Ferry was already actively
engaged in developing some of the world's smallest transistors.
The field, called "Ultra-Small Devices" in the
later part of the 1970's, was in its infancy and Dr. Ferry's
research team was one of only four select groups around
the world aggressively researching the limits of small electronic
Today, Dr. Ferry heads up the Nanostructures Research Group at Arizona State University (ASU) in Tempe, a collection of faculty, staff and students working on research in the regimes of nanolithography, and the physics of nanostructures and ultra-small semiconductor devices. The group is part of the University's College of Engineering, Center for Solid State Electronics Research, whose alumni makes up a serious constituency throughout the nanoelectronics universe, in both industry and academia.
current interests lie in the area of quantum dots,
quantum wires and ultra-small semiconductor devices
in a variety of materials. The group conducts a
wide spectrum of theoretical studies of quantum
transport in these very small devices. For example,
they are doing a process called scanning gate microscopy
at low temperatures. This involves taking the equivalent
of an atomic force microscope and putting bias on
it and studying the change in conductance of small
semiconductor structures as they move this bias
tip around on a surface.
Their system is mounted in a large cryogenic cooler, an enclosed container with a helium-3 cooling system, an isotope of a helium molecule - which is brought down to 300-milli-Kelvin, or 1,000-times below room temperature, about one-half degree above absolute zero. The cooler has a vacuum jacket around it so the heat can't transmit in, and it protects the cold from being mitigated by the ambient room temperature.
The Atomic Force Microscope (AFM) tip is on a cantilever. Normally, with the AFM, you just move this cantilever along the surface then note the change in position as it goes over topography on the surface. Dr. Ferry's group is utilizing a process called a piezo-electric sensor. They metalicize the AFM cantilevered tip with a very thin layer of metal so they can apply a voltage to it - then use that voltage to perturb the structure they are looking at. As the tip moves it creates a voltage across the plane, which is measured to determine certain mechanical property values. This is a technique that was developed at Harvard four to five years ago.
This type of experimentation is not uncommon, similar experiments are being done by a large number of universities. But what is not common, is the system that the Nanostructures Research Group is using for vibration isolation: negative-stiffness vibration isolation, developed by Minus K Technology (www. minusk.com) - which provides a significantly greater and more stable attenuation of the critical lower vibration frequencies, and therefore more reliable accrued data sets.
When measuring a very few angstroms or nanometers of displacement, you have got to have an absolutely stable surface upon which to rest your instrument. If you do not, any of that vibration coupled into the mechanical structure of your instrument will cause vertical noise, and fundamentally an inability to measure these kinds of high resolution features.
"Any kind of vibration noise in the system makes that AFM cantilever tip move, and that gives you bad signals and incorrect data," says Dr. Ferry. "We actually went further than most university applications because we integrated a rather large magnet into our system, something that Harvard, for example, is just now putting into their operation. The magnet allows us to look at different types of transport. We can turn the magnet on and look at the magneto-transport of the semiconductors. It is a quite a different mode of transport altogether."
entire system had to be isolated, not just the cantilever,"
continues Dr. Ferry. "We required an extremely
high level of vibration isolation given our research
parameters. We are deriving modern electronic devices
from our experiments. Future electronic devices
are our interest. What we are doing is looking at
the conductivity of materials and then seeing how
quantum mechanics fits into this. We study basic
physics which has a real application - engineering
- and particularly in the semiconductor industry.
Our research covers:
(1) Electron beam lithography of quantum dots and quantum devices, with applications such as quantum ballistic transport at very low temperatures and high magnetic fields, as well as the quantum-classical transition, and the role of quantum effects in real devices at room temperature."
Magneto-transport studies used to probe the nature
of electron dynamics in semiconductor quantum dots,
which are quasi-zero-dimensional structures whose
size is comparable to the Fermi wavelength of the
electrons themselves. Magneto-transport studies
may be used to probe these phenomena and to determine
the factors which limit electron phase coherence
within the structures. Current interest in these
devices is motivated by their potential application
in new areas of technology, such as quantum computing
and ultra high frequency signal processing."
"(3) Surface chemical analysis performed with a scanning Auger microprobe. Under good conditions, a lateral resolution of about 25 nm is achievable."
"(4) Professor Michael Kozicki, in the group, has examined Chemically Enhanced Vapor Etching (CEVE) patterning technique. He has used hydrocarbon contamination layers from laboratory air or vacuum chamber ambients and successfully demonstrated nanoscale pattern formation in silicon dioxide. He has also developed a nitrogen chamber coupled directly to a UHV STM/AFM facility for CEVE processing of silicon dioxide resists and their use in semiconductor device fabrication. Within the nitrogen chamber there is a processing system for the actual CEVE development."
"But, the current work with the scanning probe system is really interesting, and made possible by the negative-stiffness isolators," says Dr. Ferry."
negative-stiffness isolator is a passive isolation
approach, and has a key advantage in that it is
not powered. It has no electricity going to it.
So, in a site where heat buildup could be an issue,
such as with enclosed cryogenic chambers, negative-stiffness
becomes a highly efficient option.
Negative-stiffness isolators employ a unique - and completely mechanical - concept in low-frequency vibration isolation. Vertical-motion isolation is provided by a stiff spring that supports a weight load, combined with a negative-stiffness mechanism (NSM). The net vertical stiffness is made very low without affecting the static load-supporting capability of the spring. Beam-columns connected in series with the vertical-motion isolator provide horizontal-motion isolation. The horizontal stiffness of the beam-columns is reduced by the 'beam-column' effect. (A beam-column behaves as a spring combined with an NSM.) The result is a compact passive isolator capable of very low vertical and horizontal natural frequencies and very high internal structural frequencies. The isolators (adjusted to l/2Hz) achieve 93% isolation efficiency at 2 Hz, 99% at 5 Hz, and 99.7% at l0 Hz.
Negative-stiffness isolators provide a capability quite
unique to the field of nanotechnology - specifically,
the transmissibility of the negative-stiffness isolator.
That is, the vibration that transmits through the isolator
as measured as a function of floor vibrations - which
is substantially improved over active isolation systems.
Although active isolation systems have fundamentally
no resonance, their transmissibility does not roll off
as fast as negative-stiffness isolators. So, at building
and seismic frequencies the transmissibility of active
isolators can be 10X greater than negative-stiffness
isolators. This causes substantial adverse measurement
and imaging artifacts in the data.
Compared to other laboratory research instrumentation, the growth of AFM usage has been quite extensive over the past 10-years. AFM equipment placement has gone through a doubling phase pretty much every year during the last decade. Since its inception in 1988, it has continuously proven to be a key tool in moving nanotechnology research forward.
"More than half of the universities in the United States and worldwide, are engaging in nanotechnology research," says Dr. Ferry. "In the electronic area, the nanoelectronic side of it has been going since the late 1960's. This is driven by the fact that in the semiconductor industry all things are getting smaller and smaller. Today, the transistors have critical dimensions down around 25 nanometers. And the most critical dimension is the oxide thickness which is 1 nanometer. When you consider that you have to control one nanometer vertical thickness over 300-millimeters of lateral dimension, that is a difference of 10 to the 8th power. That defines what modern manufacturing technology produces. The need for effective vibration isolation has never been greater, and will continue to become more demanding as the nano-industry progresses."
The full article can be found at:
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Science and Technology Institute
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