Deepak Srivastava, NASA Ames, USA Computational Nanotechnology of Nanomaterials and
Abstract: Role of computational nanotechnology
in advancing the possibilities and knowledge base in nanomaterials, electronics,
sensors and machines is described through use of carbon nanotubes and
fullerenes in these areas. Using large-scale classical atomistic and quantum
dynamics/transport simulations we discuss nanomechanics of carbon and
boron-nitride nanotubes in polymer composites; branched carbon nanotube
structures for molecular electronics and sensors, endo- fullerenes and
diamond nanocrystals for solid-state quantum bits applications, and model
operations of molecular gears and motor systems. Time permitting; examples
of nano-indentation and mechano-chemistry will also be described.
M. Ajayan, RPI, USA Nanomaterials synthesis
This talk will focus on the directed assembly of multiwalled carbon nanotubes
on planar substrates into highly organized structures that include vertically
and horizontally oriented arrays, ordered fibers and porous membranes.
The concept of growing such architectures is based on growth selectivity
on certain surfaces compared to others. Selective placement of ordered
nanotube arrays is achieved on patterned templates prepared by lithography
or oxide templates with well-defined pores. Growth of nanotubes is achieved
by chemical vapor deposition (CVD) using hydrocarbon precursors and vapor
phase catalyst delivery. The new technique developed in our laboratory
allows enormous flexibility in building a large number of complex structures
based on nanotube building units. We will present our understanding of
the early stages of nanotube film growth during this CVD process. It is
observed that there are select pathways during the growth process of nanotube
films on substrates, influencing the final morphology of the films developed,
and these pathways can be tailored by tuning the catalyst concentration
in the vapor phase. We will also discuss some of our recent efforts in
creating nanotube junctions and networks of related nanostructured materials.
Xin Xiang Jiang,
CSA, Canada CSA's Perspective on Nano-Materials Research
and its Potential Impact On Space Technologies
Devices/Systems (D2) - Nano
Srivastava, NASA Ames, USA
Stewart, HP Research Labs, USA Molecular Electronics: the H-P Way
It has been more than 25 years since Aviram and Ratner first proposed
single molecule diodes, yet only recently have we been able to approach
fabrication of devices that might display such single molecule properties.
In the last five years published reports have claimed single-molecule
rectification, negative-differential resistance and, most recently, transistor
Hewlett-Packard Labs initiated a dedicated effort in molecular
electronics three years ago. I will outline our work on architecture,
defect tolerance and fabrication of nanowires by epitaxial growth, catalyzed
CVD growth and imprint lithography as well as molecular efforts on ab
into modeling, monolayer film deposition and electrical device fabrication.
I will also describe detailed electrical transport characterization
of several planar electrode/ Langmuir-Blodgett molecular mono-layer /electrode
systems that show electrical switching and rectifying behavior. Investigations
of Al/Ti, Pt/Ti and Pt/Pt devices show different generic behaviors and
confirm the dominant role played by the poorly understood electrode/molecule
interface. Indeed the difficulty of controlling this electrode/molecule
contact has to date prevented any correlation between theory and single-molecule
experiment. We have nonetheless used the mono-layer switching characteristics
to demonstrate memory and logic circuits, and have begun a systematic
investigation of transport mechanisms in the simplest Pt/Pt electrode
Ferrer, CNM, Spain Circuit & System integration of MNT devices
During the last years, a strong research activity is being performed in
the new field of Nanotechnology, i.e., in the development of the technology
to fabricate, characterize and use structures from the atomic scale up
to around 100 nm. Traditional models and theories for material properties
and device operations involve assumptions based on "critical scale
lengths" that are generally larger than 100 nm. When at least one
dimension of a structure is under this critical traditional model and
theories cannot explain length, distinct behavior often emerges that.
Nowadays, scientists and engineers from many disciplines are fabricating
and analyzing nanostructures at the intermediate scale between individual
atoms/molecules and submicron structures where the novel phenomena develop.
In this way, the presentation will explain a methodological
plan of circuit and system integration of nanodevices and microdevices
in order to develop new to the aerospace applications. These activities
will be divided into four steps:
i) Integration of nanofabrication processes and methods
for the combination of microtechnology and nanofabrication.
ii) Development of nanostructures and nanodevices.
iii) Development of circuits and systems design and architecture concepts
to interconnect and combine nanoelectronic and nanomechanical devices
with the CMOS circuits.
iv) To focused the activities towards some specific application, mainly
with pre-industrial interest for the aerospacial sector in the short and
Devices/Systems (D3) - MEMS
George, NASA JPL, USA
F. de Rooij, Institute of Microtechnology University
of Neuchâtel, Switzerland Swiss Activities in MNT for Space
Abstract: Space exploration in the coming century will emphasize
on cost effectiveness and highly focused mission objectives. MEMS will
be one of the enabling technologies to create small cost, ultra-miniaturized,
and functionally focused experiments. Two examples for such miniaturization
and successful use of MEMS for space-oriented missions are described.
Experiments with cells in space have shown that important
cellular functions are changed in microgravity [1,2]. These findings are
of great interest for fundamental research as well as for possible biotechnological
applications. To analyze the modification during cell growth, a miniature
bioreactor for the cultivation of yeast cells was designed and flown twice
(1994 and 1996) aboard Spacelab. The experiment is located in a multi-user
facility developed by ESA to host biological experiments.
In view of the complexity of the instrument and the limited dimensions
of the container (63x63x85mm), the application of silicon technology to
provide pH, temperature and redox sensors as well as a micromachined pump
 and a flow sensor are of distinct advantage. IMT has designed and
fabricated these silicon devices and collaborated with the space biology
group of the ETHZ and the company Mecanex to implement them into the bioreactor.
In a completely different field of research, the characterization
airborne dust particles present in the Martian atmosphere will help to
understand the seasonal variation of the Martian climate and the geological
history of the planet. The Mars Environmental Compatibility Assessment
Project (MECA) headed by JPL has been designed to analyze dust properties
like shape, size distribution and hardness. To be able to assess these
properties with nanometer resolution, it uses an Atomic Force Microscope
AFM has revealed itself as a reliable tool for characterizing the surface
topography of small samples. In principle, a sharp tip mounted on a cantilever
is brought into close proximity of the sample surface. The forces acting
between the sample and the tip slightly deflect the cantilever. Scanning
across the surface while recording this deflection provides a topographic
image of the sample.
MECA's AFM consists of a micro-fabricated silicon chip mounted on a voice-coil
scanner for controlling X, Y and Z motion. Maximum functionality was transferred
to the MEMS device of the AFM:
The redundancy of the instrument could be improved by
building an array of 8 cantilevers that can be engaged in series
The overall size of the device could be drastically reduced
by implanting stress sensors directly onto the cantilevers to detect
Diamond tips mounted on selected cantilevers in
the array could provide a low-wear material during hard surface interactions.
The entire instrument weights 20 g and has the size
of a matchbox. The instrument development was headed by IMT and realized
in close collaboration with the company Nanosurf and the Institute of
Physics (IFP) of the University of Basel. Unexpected design and management
failures during 1999 induced a drastic review of NASA's robotic missions
to Mars, causing the cancellation of MECA's flight opportunity. Newly
designed mission are scheduled for 2003, 5 and 7.
Walt Merrill, Glennan Microsystems, USA Harsh Environment Microsystems - The Glennan Microsystems
Abstract The Glennan Microsystems Initiative (GMI) was formed on June 19,
1998, by former NASA Administrator Daniel Goldin, then Ohio Governor George
Voinovich, then Case Western Reserve (CWRU) President Agnar Pytte, and
Glenn Research Center (GRC) Director, Donald Campbell. As a five-year
(1999 -2003) public/private partnership, the Initiative develops, applies
and commercializes microsystems technology for harsh environments. This
Initiative integrates and augments substantial microsystems resources
that currently exist, focuses them on areas of industrial importance and
bridges key, critical gaps to commercialization through strategic investments.
The objectives of the Initiative include both technology development and
commercialization. Current technology results to be presented include
pressure sensors and combustion emission sensor arrays both capable of
500C operation. Also, presented will be the Initiative's program in Silicon
Carbide based micromanufacturing.
The commercialization strategy of the Glennan Microsystems Initiative
to overcome barriers (existing challenges) is three fold. First, GMI,
through its industrially led strategic alliance, implements a research
and development program that is market driven and responsive to technology
gaps that exist in prospective products. Second, GMI has established an
organization that will exploit the strengths of the strategic alliance
to put together business development teams to identify and accelerate
particular pre-competitive technologies. These business teams will become
the kernels of business shells that focus on proprietary product development.
Finally, GMI intends to provide the manufacturing infrastructure for development
and early stage manufacturing of harsh environment devices. As a result,
GMI is investing in Silicon Carbide based processes in both surface and
bulk microfabrication as well as electronics and packaging to provide
a path for the manufacture of harsh environment devices. In particular
we will describe a multi-user silicon carbide (MUSiC) process recently
unveiled by the Glennan Initiative and a bulk machining process that is
scheduled for deployment in 2003. The MUSiC process is a surface micromachining
process, which uses polysilicon carbide as its structural layer material.
Similar to well known silicon based multi-user services, such as MUMPS,
the MUSiC process is being made available to organizations for fabrication
and evaluation of micro devices.
Astrium, UK Adding Value by Removing Mass
Abstract The space industry, like most other industries,
is continuously facing the challenge to reduce cost whilst at the same
time, to increase performance. Astrium believes that micro system technology
with its characteristics of low mass, low power, low volume and the potential
for enabling highly integrated systems offers an attractive way to meet
However, to fully benefit from the adoption of this technology
we must not only consider the micro system hardware, we must also consider
micro systems within the overall space system. We must address the computational
capability that will allow high levels of autonomy and collaboration and
we must change the industrial processes that are presently geared to producing
virtually hand built, low volume products - we need intelligent micro
This paper gives an overview of some of the developments
Astrium is currently engaged in to acquire an understanding of micro systems
and what it can do for our industry. It then discusses how we need to
change our approach so that we can work effectively with this new (for
Devices/Systems (D4) - MEMS
Snelling, Astrium, UK
Garcia, Sandia National Laboratories, USA
Abstract This paper discusses silicon surface micromachining technology
in the context of an optical switching function for a space imaging application.
Silicon surface micromachining (SMM) evolved in the early 1980's from
experiments conducted at the University of California at Berkeley by a
variety of researchers starting with the construction of the first polycrystalline
silicon cantilever beam by R. T. Howe and R. S. Muller [ ]. The structure
was created by chemically vapor depositing a thin layer of polycrystalline
silicon over a silicon dioxide spacer (or sacrificial) layer with subsequent
patterning and release. The term surface micromachining usually refers
to the construction of thin films via the use of sacrificial layers. In
the years that followed advances in the technology lead to the creation
of joints [ ], actuators [ , , , ] and a variety of sensors. Possibly
the first surface micromachined structure created is credited to H. C.
Nathanson who used a patterned gold film to create a cantilever beam,
which was used as a resonant gate for a field effect transistor [ ]. Silicon
surface micromachining today has evolved greatly; as many as five polysilicon
layers can be used to create a myriad of structures and devices. The surface
micromachining process can also incorporate other materials in addition
to polycrystalline silicon such as metals, nitrides or other materials.
Sandia National Laboratories offers a five-level process to external customers
at this time (SUMMiTTM V Process). Surface micromachining can also be
obtained at a number of other places in North America, Europe and Asia
Shanghai Institute of Metallurgy, China MEMS and Pico-Satellite in Chinese Academic
Krotz, EADS-CRC, Germany Aerospace Applications of Mass Market MEMS Products
Kruzelecky, MPB, Canada
The Application of Thin-film Smart coatings for the Miniaturization of
Thin films based on transition metal oxides can exhibit significant changes
in their crystallographic structure, and corresponding electrical and
optical characteristics, in response to external stimuli such as temperature
and electric field. Many of the transition metals such as W, Mn, La, and
V, are characterized by partially-filled d-orbitals that contribute to
the metallic bonding and electrical conduction. The transition metals
can readily form a variety of complexes involving the d-orbitals (two
eg and three t2g orbitals). Chemical bonding of the transition metals
to various ligands, such as oxygen, can produce an energy splitting, Do,
of the d-orbitals into a higher energy eg-orbital pair and a lower energy
t2g-orbital triplet due to electrostatic ionic and electron-electron interactions.
Depending on the electron occupancy of the d-related orbitals in the complex,
the energy splitting of the original transition metal d-orbitals can result
in an effective band-gap for optical absorption and conduction, producing
insulator-like behaviour. By increasing the effective population of conduction
electrons in the complex through optical biasing, temperature or field-effect,
a transition to a metallic state can be induced at a critical electron
concentration and/or temperature.
The evolution of guided-wave optics and linear detector technology has
created new possibilities for the realization of miniature integrated-optic
spectrometers for the infrared, such as MPBT's IOSPECTM, with performance
characteristics that can rival much larger FT-IR spectrometers. Miniature
integrated spectrometers coupled to advanced linear detector arrays can
facilitate a significantly smaller and lightweight space payload, with
operational characteristics that are more robust with respect to the operating
environment. The main performance advantage of FT-IR spectrometers is
their large effective input aperture. In dispersive spectrometers such
as IOSPEC, higher resolution is obtained using narrower input slits. However,
this limits the input optical collection efficiency, reducing the attainable
SNR. Using optical coding techniques, the single slit can be replaced
by an Ns array of VOn programmable apertures. This can provide up to a
Ns1.5 gain in SNR relative to the single-slit spectrometers due to signal
multiplexing and data redundancy, providing performance that can surpass
much larger FT-IR spectrometers. The compact size and minimal power requirements
of these integrated spectrometers allows space deployment in relatively
economical small-sat and microsat platforms for atmospheric studies and
on planetary rovers for surface exploration. The resulting infrared absorption
or reflection spectra can provide chemically-specific identification of
the presence of water, minerals, various biochemicals and bacteria.
Devices/Systems (D5) - Precision
MEMS Sensors and Gyroscopes
Universita di Roma La Sapienza, Italy Chemical Microthrusters: Effects of Scaling
With the emergence of micro and nanosatellites, recent work has started
on chemical microthrusters (e.g., deGroot and Oleson, 1996; Beardsley,
1999; Alexchenko et al., 2000). This work has indicated that simple ("geometric")
size reduction of chemical thrusters for micro and nanosatellites is based
on the argument that thrust (from ideal 1-D rocket theory) scales with
throat area , while weight scales with volume . Thus, shrinking a chemical
rocket should raise the ratio, a very attractive trend. However, scaling
laws should be considered for all physical effects; in fact Ketsdever
and Mueller (1999) and Ketsdever et al. (1999) have examined the effects
of viscosity and heat transfer, but not those associated with rocket combustion.
The goal of this paper is to show how the effects of miniaturizing rocket
engines can be estimated in advance, thus avoiding (costly) disappointment.
In particular, the attention is focused on combustion physics, i.e., quenching,
flame thickness and turbulence length scales. The results show intrinsic
limitations to miniaturizing rocket engines posed by combustion physics,
as well as the opportunities it provides: for instance, in taking advantage
of unwanted effects (e.g., wall heat transfer) to increase operability
ETB Codicote Innovation Centre, UK A solid state gyro, a 3 Axis Accelerometer,
and a Pressure sensor Devices and Instruments for Space Applications
European technology for Business Ltd (ETB) is a design company in the
UK, specializing in the design of physical MST sensors for a variety of
applications. Their core expertise lies in piezo-electric ceramics, resonating
devices and Microsystems. This paper describes 3 physical MST sensors
that ETB are currently developing with partners, that utilize this core
expertise, and would be suitable for certain space applications.
J. Inman, Eric Ruggiero, Virginia
Tech, US Active Dynamic Analysis and Vibration Control of
Gossamer Structures Using Smart Materials
Increasing costs for space shuttle missions translate to smaller,
lighter, and more flexible satellites that maintain or improve current
dynamic requirements. This is especially true for optical systems and
surfaces. Lightweight, inflatable structures, otherwise known as gossamer
structures, are smaller, lighter, and more flexible than current satellite
technology. Unfortunately, little research has been performed investigating
cost effective and feasible methods of dynamic analysis and control of
these structures due to their inherent, non-linear dynamic properties.
Gossamer spacecraft have the potential of introducing lenses and membrane
arrays in orbit on the order of 25 m in diameter. With such huge structures
in space, imaging resolution and communication transmissibility will correspondingly
increase in orders of magnitude.
A daunting problem facing gossamer spacecraft is their
highly flexible nature. Previous attempts at ground testing have produced
only localized deformation of the structure's skin rather than excitation
of the global (entire structure's) modes. Unfortunately, the global modes
are necessary for model parameter verification. The motivation of this
research is to find an effective and repeatable methodology for obtaining
the dynamic response characteristics of a flexible, inflatable structure.
By obtaining the dynamic response characteristics, a suitable control
technique may be developed to effectively control the structure's vibration.
Smart materials can be used for both active dynamic analysis as well as
active control. In particular, piezoelectric materials, which demonstrate
electro-mechanical coupling, are able to sense vibration and consequently
can be integrated into a control scheme to reduce such vibration. This
research explores the use of NASA Langley Research Center's MFC Actuator
as both a sensor and actuator in SISO and MIMO modal analysis techniques.
Using smart materials to develop a vibration analysis and control algorithm
for a gossamer space structure will fulfill the current requirements of
space satellite systems. Smart materials will help spawn the next generation
of space satellite technology.
Devices/Systems (D6) - MEMS
chair: : Frank
Foran, CSA, Canada
Manzoni, Mechatronic GmbH, Austria Austrian-Italian Micropropulsion R&D
An experimental setup for testing in space the preliminary realization
of a micropropulsion system is under development by Mechatronic and INFM.
The experiment will be performed on-board the microsatellite UNISAT-2,
in the framework of a cooperation between Università di Roma "La
Sapienza",Mechatronic and INFM. The main goal of the experiment is
to have a preliminary assessment of the microthruster performance in orbit.
The thruster configuration for the UNISAT-2 experiment is cold-gas, using
pressurized nitrogen (N2). The micro convergent-divergent nozzles, obtained
by Microlitography and Reactive Ion Etching from 500µm thickness
silicon wafer, have a throat area of about 300µm 2 through which
the pressurized gas flow is accelerated. Ground tests have been conducted
to evaluate the microthruster performance, showing that the maximum thrust
is in the order of 500 µN. The silicon chips have been bounded to
a glass support and integrated with microvalves, microsensors and electronic
control system desinged and produced by Mechatronic. The whole micropropulsion
experiment has been integrated on the payload bay of UNISAT-2 in order
to have two pairs of microthrusters mounted with their thrust direction
orthogonal to the spin-axis of the spacecraft, and to be used to perform
spin-up/spin-down maneuvers. Measuring the satellite spin rate variation,
after thruster activation, the average thrust is evaluated.
CSA, Canada MEMS Development Programs at the CSA
Van Hoof, IMEC, Belgium Engineering and Flight model development
The presentation gives an overview of key ongoing space microelectronics
activities at IMEC in the areas of technology, flight hardware development
and design. Technology development concerns MEMS switches, concentrator
solar cells and infrared imagers. Flight model development concerns integrated
radiation-tolerant CMOS image sensors, cryogenic sensor readout electronics
and advanced sensor readout circuits. Design related activities concern
an FPGA implementation of a wavelet based flexible compression engine,
a generic Turbo codec ASIC implementation as well as the realisation of
a radiation tolerant design library for commercial CMOS based ASIC technologies.
Devices/Systems (D7) - Nano
chair: : Tim
Harper, European NanoBusiness Association, Spain
Klocke, Klocke Nanotechnik, Germany Nanorobotics for the International
Space Station / Nanomotors for RF technology
In the presentation actuators and Nanorobotics will be described including
possible aerospace applications. As basic element the Nanomotor delivers
atomic resolution at up to 70 mm of stroke. It is the smallest and most
precise linear motor worldwide and offers a set of advantages for space
applications. The Nanomotor is:
· Ultra high vacuum compatible
· Low temperature compatible down to 4 Kelvin, even inside of liquid
· It needs only low voltages
· It can hold its position without power supply
· An integrated sliding clutch allows force limitations
· The Nanomotor can act as "Micro-jackhammer" to process
These properties are an important help for a space qualification.
Besides this small linear actuator, positioners with many
degrees of freedom, manipulators and complete Nanorobotics systems will
A wide range of high precision applications can be realized
like high-frequency tuners for satellites, Mini-spectrometers, devices
to move objects like a shutter (e.g. Sojourner Rover), actuators for mini-satellites,
or a complete handling station for the International Space Station. For
the realization of experiments in the International Space Station it is
often necessary to handle objects for preparation or storage. But the
time of the astronauts is expensive. The Nanorobotics system from Klocke
Nanotechnik can solve these tasks by Joystick control, even from the earth
The Nanorobotics series builds a bridge between nanotechnology
and the classical mechanical engineering. These products combine the advantages
of both technologies: the backlash free movement with resolution of better
10 nanometer and the capability of kilograms of load at centimeters stroke.
This series of the smallest and most precise positioning modules offers
plenty degrees of freedom in smallest volume for microassembly, interconnection
technology, analysis and reliability testing. The repeatability of classical
assembly lines is limited to a few microns. The Nanorobotics modules allow
absolute positioning within 50 Nanometers. These properties are good enough
even for future applications that cannot be predicted now, an important
feature for a longtime investment.
A handling system made with Nanorobotics can transport
objects with diameters between some 10 microns and some 10 Millimeter.
The system can be controlled by Joystick - in combination with cameras
even from the earth. Integrated position sensors allow the automatic usage.
For live science the transport of smallest drops can be realized, gravity
has no influence.
Astrium, Germany MST technology roadmap and MST in-orbit
Devices/Systems (D8) - Nano
chair: : Prakash
Patnaik, IAR-NRC, Canada
of Canterbury, New Zealand Nanowires and Control of Nanoparticle Deposition
Random deposition of conducting nanoparticles on a flat two dimensional
(2D) substrate leads to the formation of a conducting path at the percolation
threshold. In sufficiently small systems significant finite size effects
are expected. However, in the 2D square systems that are usually studied,
the random deposition means that the main effect of small system sizes
is that stochastic fluctuations become increasingly large.
We have performed experiments and simulations on rectangular
2D nanoparticle films with nanoscale overall dimensions.  The sample
geometry is chosen to limit stochastic fluctuations in the film's properties.
In the experiments bismuth nanoparticles with mean diameters in the range
20-60nm are deposited between contacts with separations down to 200nm.
When the maximum number of clusters that fit between the contacts is ~5
we are able to show that a conducting nanowire, which is automatically
connected to electrical contacts, is formed close to the percolation threshold.
Percolation theory describes the experimental onset of conduction well:
there is good agreement between predicted and measured values of the power
law exponent for the correlation length.
We have also performed extensive measurements of the conductivity
of samples with a wide range of nanoparticle densities. Dramatic steps
in the conductivity are observed while ramping the applied bias, due to
electrically driven changes in the connections between nanoparticles.
Field emission SEM measurements have been performed to assist the interpretation
of the conductivity data.
Finally we show that our understanding of percolation in
these devices can be used to provide a convenient method of local, real-time,
sub-monolayer control of particle deposition.
Michel Meunier, Ecole Polytechnique
Montreal Laser Micro-Nano Engineering of Materials
Stansfield, INRS, Canada Carbon Nanotubes
Devices/Systems (D9) - Nano
Ferrer, CNM, Spain
Mehrez, Harvard University, USA Theoretical Modeling of Electronic Transport
Through Nano-Structure Devices
Electronic transport through nano-devices is quite different from micro-systems
due to the absence of electronic scattering in such small structures.
This results in Ballistic, rather than diffusive transport in these systems.
In addition to this, the small number of atoms in these devices, enhances
environmental effects and becomes more difficult to interpret experimental
data. Hence, investigations from first principles are required. Recently,
new approaches, within Local Density Approximation, have been developed
to investigate current-voltage (I-V) characteristics of nano device systems.
Using such a model, we have analyzed non-linear I-V characteristics of
Gold nano-wires and we have found qualitative as well as quantitative
agreement with the recent experimental measurements. Our investigations
show that clean Gold nano-wires exhibit linear behavior, whereas non-linearity
emerges due to impurity effects at the contact. In this talk we will give
some details of the recent experimental data, briefly explain the theoretical
model, show our numerical results and compare them with the experiment.
Another important effect that emerges in such systems, is electron-phonon
coupling. Due to the low atomic coordination number in such devices, adding
an extra electron to the system results in atomic and electronic eigen-states
rearrangement; and hence different electronic transport while compared
with the static structure. This usually decreases the electronic gap of
semi-conductor nano-devices and electronic transport is polaronic assisted.
However, to investigate such a phenomenon requires dealing with a large
phonon basis set. We have recently developed an approach to partially
overcome this problem. We will describe our method and results within
Su-Schrieffer-Heeger model of one-dimensional chain. Our simulations show
that polaron assisted electronic transport enhances the zero bias conductance
of semi-conductor chains, especially longer ones where the pure electronic
transport is largely reduced.
Devices/Systems (D10) -
Photonics and Bio Nanotechnology
Ghosh, CSA, Canada
Rossi-Bazin, LAAS Laboratory, France The Development of Solid propellant uRockets
Scientists and space community agree that Microsystems technology will
revolutionize space industry. The benefits would be a reduction of parts
because of a better integration of each component, a decrease of material
variability and a better reliability. Of course, the resulting benefits
would be a mass reduction and a lower fabrication cost. In this tendency,
every subsystems of the satellite may be re-envisioned and miniaturized.
Propulsion are a key point in the miniaturization of spacecrafts because
micro and nanospacecrafts would need very small (below the Newton) and
very accurate force to realize the stabilization, the pointing and the
This paper presents a solid propellant
microrocket devices for micropropulsion needs. The concept is based on
the high rate combustion of one single propellant stored in a combustion
chamber. The lack of restart ability is compensated by the fabrication
of arrays of microrockets. The gas generated by the combustion of the
propellant is accelerated in a nozzle thus delivering a thrust. One single
rocket consists of a stack of 3 parts of silicon:
1. A silicon micromachined igniter with a polysilicon resistor patterned
onto a very thin dielectric membrane.
2. A propellant chamber.
3. A diverging part wafer can be added on top of the structure if necessary.
Sagman, C Sixty Inc., Canada Nanomedicine: Fullerene and Nanotube Biology
The direct application of nanoscale materials to biological
targets is now yielding promising applications in medicine. This talk
will review the field of fullerene and carbon nanotube biology, as well
as describe current applications of fullerene derivatives in biology and
The flexible chemical reactivity of fullerene-C60 has already
resulted in the synthesis of numerous fullerene compounds that are now
available for study. In addition, at 7.2 A in diameter, C60 is similar
in size to steroid hormones or peptide alpha-helices and thus fullerene
compounds are ideal molecules to serve as ligands for enzymes and receptors.
Other fundamental physical and chemical properties of fullerenes
govern how they may be adapted for biological use. While fullerene-C60
itself shows no solubility in water, many fullerene compounds can be very
water soluble. Such derivatives of C60 contain polar side chains and,
as a general rule, the greater the number of polar groups the greater
the water solubility. In order to maximize the chances of advantageous
adsorption and distribution properties of bioactive compounds, it is generally
accepted that there are certain desirable ranges of lipophilicity and
several fullerene compounds have already been reported that are in favorable
Numerous useful fullerene-based therapeutics have
already been developed, including anti-viral agents, neuroprotective agents,
and anti-cancer drugs, as well as biosensors for diagnostic applications.
The use of these fullerene-based nanoscale products for pharmaceuticals
and for medical device applications will be discussed, including the advance
of fullerene-based therapeutics to human clinical trials
(D11) - Micro Machined Silicon
Sensors and Actuators for Space Applications
Daniel Inman and Eric Ruggiero, Virginia Tech
Dommann, Interstate University of Applied Science,
Accurate Microscopic Method to Investigate the Aging of Micromachined
Abstract: We compare the strain and dislocation density induced
by thermally grown silicon dioxide on silicon wafers with those in a microfabricated
thermal bimorphous beam actuator as well as the influence of aging on
these parameters. A high-resolution x-ray diffractometer allows measuring
the strain of a crystal. This is an accurate, non-destructive microscopic
method applied in the field of MEMS to obtain quantified results on the
crystalline disorder. Aging of a micromachined silicon actuator results
in a change of the strain profile. The method is applied to a bimorphous
Si/Al actuator on which hysteresis was observed. It is shown, that thin
film thermal silicon dioxide stresses the silicon much less then aluminum,
which was found to cause the observed aging of the bimorphous structure.
By removing the aluminum layer, almost complete relaxation could be observed.
Ayazi, Georgia Tech, USA Enabling Technology (HARPSS) Which Can be
Used to Make Both High Precision Gyroscopes and MEMS Resonators.
This talk will present the applications of the HARPSS process to integrated
RF and sensory micro-electro-mechanical systems. HARPSS (High Aspect-Ratio
Poly and Single-Crystal Silicon) is an all-silicon MEMS technology that
is capable of producing self-aligned nanometer-in-size vertical airgaps
in between 1-10's of microns thick high quality factor silicon structures.
This technology provides features required for implementation of high-precision
inertial sensors (accelerometers and vibratory gyroscopes) as well as
high frequency electrostatic micromechanical resonators for RF applications.
High-Q MEMS resonators are prime candidates to replace frequency references
and bandpass filters in future integrated RF transceiver systems. The
all-silicon feature of the HARPSS technology improves long term stability
and temperature sensitivity while fabrication of large area, vertical
capacitors with sub-micron gap spacing will increase the sensitivity by
orders of magnitude. The latest results on application of this technology
to RF and sensory MEMS will be presented in this talk.