NOVEMBER 2010 - DRAFT NANOTECHNOLOGY ROADMAP TECHNOLOGY AREA 10 - MICHAEL A. MEADOR, CHAIR BRADLEY FILES JING LI HARISH MANOHARA DAN POWELL ...
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National Aeronautics and Space Administration
DRAFT Nanotechnology Roadmap
Technology Area 10
Michael A. Meador, Chair
Bradley Files
Jing Li
Harish Manohara
Dan Powell
Emilie J. Siochi
November • 2010
DRAFT
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DRAFT
Table of Contents
Foreword
Executive Summary TA10-1
1. General Overview TA10-6
1.1. Technical Approach TA10-6
1.2. Benefits TA10-6
1.3. Applicability/Traceability to NASA Strategic Goals, AMPM, DRMs, DRAs TA10-7
1.4. Top Technical Challenges TA10-7
2. Detailed Portfolio Discussion TA10-8
2.1. Summary Description TA10-8
2.2. WBS Description TA10-8
2.2.1. Engineered Materials TA10-8
2.2.1.1. Lightweight Materials and Structures. TA10-8
2.2.1.2. Damage Tolerant Systems TA10-9
2.2.1.3. Coatings TA10-10
2.2.1.4. Adhesives TA10-10
2.2.1.5. Thermal Protection and Control TA10-10
2.2.1.6. Key Capabilities TA10-11
2.2.2. Energy Generation and Storage TA10-12
2.2.2.1. Energy Generation TA10-13
2.2.2.2. Energy Storage TA10-13
2.2.2.3. Energy Distribution TA10-14
2.2.2.4. Key Capabilities TA10-14
2.2.3. Propulsion TA10-14
2.2.3.1. Nanopropellants TA10-14
2.2.3.2. Propulsion Systems TA10-15
2.2.3.3. In-Space Propulsion TA10-16
2.2.3.4. Key Capabilities TA10-17
2.2.4. Electronics, Devices and Sensors TA10-17
2.2.4.1. Sensors and Actuators TA10-17
2.2.4.2. Electronics TA10-17
2.2.4.3. Miniature Instrumentation TA10-18
2.2.4.4. Key Capabilities TA10-19
3. Supporting Technologies TA10-19
4. Interdependency with Other Technology Areas TA10-21
5. Possible Benefits to Other National Needs TA10-22
Acronyms TA10-23
Acknowledgements TA10-23
DRAFT
Foreword
NASA’s integrated technology roadmap, including both technology pull and technology push strategies,
considers a wide range of pathways to advance the nation’s current capabilities. The present state of this effort
is documented in NASA’s DRAFT Space Technology Roadmap, an integrated set of fourteen technology
area roadmaps, recommending the overall technology investment strategy and prioritization of NASA’s space
technology activities. This document presents the DRAFT Technology Area 10 input: Nanotechnology. NASA
developed this DRAFT Space Technology Roadmap for use by the National Research Council (NRC) as an
initial point of departure. Through an open process of community engagement, the NRC will gather input,
integrate it within the Space Technology Roadmap and provide NASA with recommendations on potential
future technology investments. Because it is difficult to predict the wide range of future advances possible in
these areas, NASA plans updates to its integrated technology roadmap on a regular basis.
DRAFT
Executive Summary cells will enable the development of flexible, radi-
Nanotechnology involves the manipulation of ation tolerant solar cells with >50% efficiencies.
matter at the atomic level, where convention- These could be incorporated into the exterior of
al physics breaks down, to impart new materials habitats and rovers providing for integrated power
or devices with performance characteristics that sources at reduced systems weight.
far exceed those predicted for more orthodox ap- Enhanced Power Generation and Storage and
proaches. For example, quantum confinement in Propulsion
nanoscale semiconductor particles, quantum dots, Nanotechnology affords the possibility of cre-
gives rise to novel optical behavior making it pos- ating high surface area materials with inherently
sible to tune the color of their fluorescence sim- higher surface activities and reactivity that could
ply by changing their diameter. Nanoscale textur- significantly enhance the performance of batteries
ing of surfaces can allow for control of adhesion and fuel cells and improve the handling character-
properties leading to biomimetic (Gecko-foot) istics of propellants. Use of nanostructured met-
self-healing adhesives and self-cleaning surfaces. al catalysts in PEM fuel cells could increase their
The unusual combination of superior mechani- energy density by 50%. Use of nanoporous mate-
cal properties, electrical and thermal conductivi- rials and nanocomposites could enable the devel-
ty and electronic properties of carbon based nano- opment of new batteries that could operate over a
structured materials can enable the development wide temperature range, from -100 to 100°C, to
of lightweight, multifunctional structures that will provide surface power for rovers and EVA suits.
revolutionize the design of future aerospace sys- Nanoscale metal based propellants could replace
tems. Nanotechnology can have a broad impact cryogenic propellants and hypergolics leading to
on NASA missions, with benefits principally in simplified storage, transfer and handling and re-
four areas. duced launch pad and in-space operational re-
Reduced Vehicle Mass quirements.
Replacement of conventional aerospace materi- Improved Astronaut Health Management
als (composites and metals) with advanced com- Nanoporous materials with tailored pore size
posites derived from durable nanoporous matrix- and shape and surface chemistries will lead to the
es and low density high strength and/or stiffness development of more efficient systems for the re-
fibers can reduce aircraft and spacecraft compo- moval of carbon dioxide and other impurities
nent weight by one-third. Additional weight sav- from breathing air and organic and metallic im-
ings can be realized by replacing heavy copper wir- purities from drinking water. Distributed, auton-
ing, which accounts for 4000 lb of weight on a omous state and chemical species detectors could
Boeing 747 and about one-third of the weight of find use in air and water quality monitoring sys-
large satellites, with low density carbon nanotube tems, and in astronaut health monitoring. Nano-
wiring cables. Use of structural aerogel insulation fluidics based devices will enable the development
in place of multilayer insulation (MLI) for cryo- of real-time, minimally invasive medical diagnos-
tanks can eliminate the need for external foam in- tic systems to monitor astronaut health and aid
sulation and the associated parasitic weight and in diagnosing and treating illness. Electrospun
production costs. nanofibers with demonstrated potential to sup-
Improved Functionality and Durability port tissue engineering and regenerative medicine
Nanoelectronic devices based upon graphene, can expand and radically change astronaut health
carbon nanotubes, semiconductor nanowires, management methods. Boron nitride or carbide
quantum dots/semiconductor nanocrystals and based nanocomposites could be used as part of
rods, are inherently more radiation and fault toler- a habitat or rover structure, providing radiation
ant, have lower power requirements, higher speeds shielding and MMOD protection.
than conventional CMOS electronics. Integration A 20 year roadmap was created for the develop-
of nanoelectronics and nanotechnology derived ment and application of nanotechnology in NASA
emission sources and detectors will lead to the de- missions. This roadmap addresses mission needs as
velopment of advanced spectrometers and imag- well as identifies nanotechnology that could lead
ers that are one to two orders of magnitude light- to the benefits discussed above and enable radi-
er than conventional instrumentation, with twice cal changes in the way aircraft and spacecraft are
the sensitivity and resolution and half the power designed and NASA missions are conducted. The
requirements. Quantum structure enhanced solar roadmap is subdivided into four themes – Engi-
DRAFT TA10-1
neered Materials and Structures, Energy Gener- ing these challenges can be leveraged with those of ation, Storage and Distribution, Propulsion, and other federal agencies to accelerate developments Electronics, Sensors and Devices. Five Grand in this area and address NASA specific needs. Challenges were identified that would enable the Development of integrated energy generation, development of nanotechnologies with the most scavenging and harvesting technologies. impact on NASA Missions. Increased investment The use of quantum structures (dots and rods) in these areas will accelerate the technology devel- to enhance absorption of solar energy and carbon opment. nanotubes to improve charge transport and de- Development of scalable methods for the con- velop transparent electrodes will enable the devel- trolled synthesis (shape and morphology) and opment of flexible, radiation hard solar cells with stabilization of nanopropellants. greater than 50% efficiencies. Nanostructured High surface area and reactivity (metallic and electrode materials, self-assembled polymer elec- inorganic) nanoparticle co-reactants or gelling trolytes and nanocomposites will enable the de- agents can be used to develop alternatives to cyro- velopment of new ultracapacitors with 5 times the genic fuels and hypergolics. Nanopropellants have energy density of today’s devices and new, lighter the potential to be easier to handle and less tox- and safer lithium batteries. Incorporation of flex- ic than conventional propellants, leading to sim- ible, conformal photovoltaics and improved ef- plified storage and transfer. A propellant com- ficiency, lightweight, flexible batteries into EVA prised of nanoscale aluminum particle/ice slurry suits and habitats would lead to enhanced pow- was recently demonstrated in tests by a team of er and reduced mass and enable longer duration researchers from Purdue and Penn State in a suc- EVA sorties and missions. Developments need- cessful rocket launch. Technical issues that need to ed in this area include functionalization chemis- be addressed includes the development of passiv- tries to allow incorporation of carbon nanotubes ation chemistries to control unwanted oxidation into devices, reliable, repeatable large scale man- and the development of processing methods to ufacturing methods, as well as approaches to en- tailor the shape, composition and morphology of hance radiation tolerance and nanoengineered these nanoparticles for controlled burning charac- coatings to prevent dust accumulation. An in- teristics and methods to produce nanopropellants creased NASA investment in this area can be lev- in large scales with good batch-to-batch consisten- eraged against ongoing efforts at Energy Frontier cy. NASA is currently partnering with other feder- Research Centers as well as the upcoming NNI al agencies in this area, but more work and invest- Solar Energy Signature Initiative. ment is warranted. Development of nanostructured materials Development of hierarchical systems integra- 50% lighter than conventional materials with tion tools across length scales (nano to micro). equivalent or superior properties. High sensitivity and low power sensors (ppb to Carbon nanotube derived high strength and ppm level at μW - nW), high-speed (hundreds modulus, low density carbon fibers and light- of GHz) electronics, and measurement enabling weight, high strength and durability nanoporous nanocomponents for miniature instruments are polymers and hybrid materials will enable the de- bound to interface with larger (micro, meso, and velopment of advanced composites that would re- higher) systems to accomplish desired operation. duce the weight of aircraft and spacecraft by up System integration issues at that level can pose sig- to 30%. Technical challenges that need to be ad- nificant challenges and require the design of de- dressed include the development of reliable, low vices and processes that are suitable for both nano cost manufacturing methods to produce nano- and microstructure fabrication schemes (chem- tubes, fibers and nanocomposites in large quanti- ical, thermal, and mechanical issues), structur- ties and systematic studies to understand damage al integration techniques that are mechanically progression, degradation and long-term durabil- and thermally robust, and the development of ef- ity of these advanced composites to enable their ficient interconnects. In addition, a better under- efficient use in future aerospace vehicles. This standing of factors that can degrade system per- technology area would be well suited for an NNI formance, such as the effect of nano-micro-meso Signature Initiative that could be led by NASA. interfaces, packaging, and signal interference at Development of graphene based nanoelectron- component level, is needed along with effective ics. mitigation strategies. NASA investments in meet- Graphene based nanoelectronics can enable the TA10-2 DRAFT
Figure R: Nanotechnology Technology Area Strategic Roadmap (TASR)
DRAFT TA10–3/4
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development of radiation hard, high-speed de-
vices, flexible electronic circuits, and transparent
electrical conductors (a superior replacement for
indium-tin-oxide coatings) that would find broad
applications in NASA missions in exploration,
science and aeronautics. Technical challenges that
need to be addressed include the development of
reliable, reproducible, and controlled methods
to produce graphene on a large scale, a clear un-
derstanding of graphene and dielectric interfac-
es, device physics, foundry-conducive processes
to produce large scale electronic circuits, and het-
erogeneous system integration issues. A concert-
ed collaborative development supported within
NASA and by other Federal agencies, including
efforts in the planned NNI Nanoelectronics Sig-
nature Initiative, can realistically make graphene
electronics a system of choice for avionics, ex-
treme environment applications, an integral part
of “smart” skin material (EVA suits), and for fu-
ture probes and planetary landers by 2028-2032.
In addition to meeting NASA needs, these nan-
otechnology Grand Challenges can also help meet
National needs in clean energy and National secu-
rity. Advanced structural nanomaterials and nano-
engineered coatings can be used to develop light-
weight, more damage tolerant turbine blades for
wind energy that are less susceptible to ice accre-
tion and insect fouling. Advanced aerogel insula-
tion can be used to improve the energy efficien-
cy of homes and buildings. Nanotube electrical
wiring can have a significant impact on reduc-
ing resistivity losses in electrical power transmis-
sion lines. Advanced photovoltaics, batteries and
fuel cells can also meet needs for clean energy stor-
age and generation. Nanoelectronics, sensors and
actuators, and miniature instruments have wide
use in many applications to meet other National
needs. For example, nanosensors possess high sen-
sitivity, low power and small size that can fit in a
cell phone for extended coverage of sensing net-
work for homeland security applications in detect-
ing toxics and chemical threats. Such a cell phone
sensor can be used in a clinic or at home for med-
ical diagnosis and point of care health monitoring
as well as by first responders for natural disasters
and other accidents to determine the cause of in-
cident and decide on the best approaches to solve
it. Nanosensors can form a wired and/or wireless
network that can be used to monitor the safety of
a building or a stadium as well as for battlefield
chemical profiling.
DRAFT TA10-5
1. General Overview Figure 2. Carbon
nanotube Gecko-
1.1. Technical Approach foot adhesive
Nanotechnology involves the manipulation (P.M.Ajayan,
of matter at the atomic level where convention- Rice University)
al physics breaks down to impart new materi-
als or devices with performance characteristics
that far exceed those predicted for more ortho-
dox approaches. Quantum confinement in na-
noscale semiconductor particles, quantum dots,
gives rise to novel optical behavior making it pos-
sible to tune the color of their fluorescence simply identified as potential candidates for further de-
by changing their diameter (Figure 1). Nanoscale velopment along with selected mission critical
texturing of surfaces can allow for control of ad- technologies, such as those related to astronaut
hesion properties leading to biomimetic (Gecko- health management or miniaturized instrumenta-
foot) adhesives and self-cleaning surfaces (Figure tion for planetary exploration. Technical challeng-
2). The combination of superior mechanical prop- es were identified that enable the development of
erties, electrical and thermal conductivity and these technologies and are also presented in this
electronic properties of carbon based nanostruc- document. In addition, five Grand Challenges are
tured materials can revolutionize the design par- highlighted that, if successfully addressed, would
adigm for lightweight multifunctional structures. revolutionize NASA’s missions and the aerospace
Nanotechnology can have a broad impact on industry as well as have significant impact on
NASA missions by enabling such advances as the meeting National needs, such as clean energy and
development of ultralightweight, multifunctional homeland security. Investments by other Feder-
materials for aircraft and spacecraft, robust fault al agencies that could be leveraged to help tackle
tolerant electronics, high sensitivity, low power these Grand Challenges were also identified.
sensors for planetary exploration and high thrust
propellants. 1.2. Benefits
This roadmap addresses a 20- year plan for the Nanotechnology can have a broad impact on
development and implementation of nanotech- NASA missions and programs in aeronautics,
nologies for NASA missions. The roadmap is or- planetary science, and exploration.
ganized into four themes – Engineered Materials Reduced Vehicle Mass
and Structures, Energy Generation and Storage, Replacement of conventional aerospace materi-
Electronics, Sensors and Devices and Propulsion. als (composites and metals) with advanced com-
Separate roadmaps for each Mission Directorate posites derived from durable nanoporous matrix-
were developed that show how nanotechnologies es and low density high strength and/or stiffness
developed in each theme can lead to new capabil- fibers can reduce aircraft and spacecraft compo-
ities to support planned missions or enable new nent weight by one-third. Additional weight sav-
missions. From these separate roadmaps, cross- ings can be realized by replacing heavy copper wir-
cutting technologies, i.e., those that are impor- ing, which accounts for 4000 lb of weight on a
tant to more than one Mission Directorate, were Boeing 747 and about one-third of the weight of
large satellites, with low density carbon nanotube
wiring cables. Use of structural aerogel insulation
in place of multilayer insulation (MLI) for cryo-
tanks can eliminate the need for external foam in-
sulation and the associated parasitic weight and
production costs.
Improved Functionality and Durability
Nanoelectronic devices based upon graphene,
carbon nanotubes, semiconductor nanowires,
Figure 1. Size depen- quantum dots/semiconductor nanocrystals and
dent fluorescence of rods, are inherently more radiation and fault toler-
quantum dots. ant, have lower power requirements, higher speeds
than conventional CMOS electronics. Integration
TA10-6 DRAFTof nanoelectronics and nanotechnology derived 1.3. Applicability/Traceability to NASA
emission sources and detectors will lead to the de- Strategic Goals, AMPM, DRMs, DRAs
velopment of advanced spectrometers and imag- While mostly a “push” technology, nanotech-
ers that are one to two orders of magnitude light- nology can have an impact on planned NASA
er than conventional instrumentation, with twice missions. Carbon nanotube based nanocompos-
the sensitivity and resolution and half the power ite struts and an engine cover plate will be flying
requirements. Quantum structure enhanced solar on the upcoming Juno mission. Exploration miss-
cells will enable the development of flexible, radi- sions will require lightweight materials for launch
ation tolerant solar cells with >50% efficiencies. vehicles and cryogenic propellant tanks, as well as
These could be incorporated into the exterior of improved energy storage and generation. In addi-
habitats and rovers providing for integrated power tion to lighter weight structures and improved en-
sources at reduced systems weight. ergy generation and storage, future science mis-
Enhanced Power Generation and Storage and sions will need lightweight, compact, low power
Propulsion science instruments. Advanced aircraft currenlty
Nanotechnology affords the possibility of cre- being planned in the Fundamental Aeronautics
ating high surface area materials with inherently Technology program will rely upon the develop-
higher surface activities and reactivity that could ment of lightweight, multifunctional materials for
significantly enhance the performance of batteries airframe components and durable, high tempera-
and fuel cells and improve the handling character- ture materials for advanced engine designs. “More
istics of propellants. Use of nanostructured met- electric aircraft” concepts will need improved
al catalysts in PEM fuel cells could increase their power generation, storage and distribution. Each
energy density by 50%. Use of nanoporous mate- of these needs could be met through the applica-
rials and nanocomposites could enable the devel- tion of nanotechnology.
opment of new batteries that could operate over a 1.4. Top Technical Challenges
wide temperature range, from -100 to 100°C, to The top technology challenges are provided in
provide surface power for rovers and EVA suits. below:
Nanoscale metal based propellants could replace
cryogenic propellants and hypergolics leading to Present to 2016
simplified storage, transfer and handling and re- • Scale-able methods for the controlled synthesis
duced launch pad and in-space operational re- (shape and morphology) and stabilization of
quirements. nanopropellants
Improved Astronaut Health Management • Development of long-life, reliable emission
Nanoporous materials with tailored pore size sources for detectors and instruments
and shape and surface chemistries will lead to the • Development of characterization tools and
development of more efficient systems for the re- methodologies to measure coupled properties
moval of carbon dioxide and other impurities of nanostructured materials, including non-
from breathing air and organic and metallic im- destructive and in situ methods
purities from drinking water. Distributed, auton- • Development of methods and knowledge-base
omous state and chemical species detectors could to optimize bulk properties of nanostructured
find use in air and water quality monitoring sys- materials
tems, and in astronaut health monitoring. Nano- 2017 to 2022
fluidics based devices will enable the development • Development of manufacturing methods,
of real-time, minimally invasive medical diagnos- including self-assembly based net shape
tic systems to monitor astronaut health and aid fabrication, to produce nanoscale materials
in diagnosing and treating illness. Electrospun and devices on large scales with controlled
nanofibers with demonstrated potential to sup- structure, morphology and quality
port tissue engineering and regenerative medicine
can expand and radically change astronaut health • Development of hierarchical systems
management methods. Boron nitride or carbide integration tools across length scales (nano to
based nanocomposites could be used as part of micro)
a habitat or rover structure, providing radiation • Development of integrated energy generation,
shielding and MMOD protection. scavenging and harvesting technologies
2023 to 2028
• Development of nanostructured materials that
DRAFT TA10-7are 50% lighter than conventional materials tems, Coatings, Adhesives and Thermal Control
with equivalent or superior properties and Protection. A more detailed description of
• Development of high fidelity and reliability each of these topics follows.
multi-scale models to predict the properties 2.2.1.1. Lightweight Materials and Structures.
of nanoscale materials and efficiently translate A comparison of the predicted specific strength
these properties into the design of new devices and stiffness of single wall carbon nanotubes,
and structures SWNT, with measured properties of convention-
• Development of graphene based electronics al carbon fiber reinforced composites, CFRP, and
Beyond 2028 various aerospace materials is shown in Figure 5.
• Development of high specificity, single While the ultimate goal of developing contin-
molecule detection methods uous single wall carbon nanotube fibers has yet
to be realized, considerable research has been fo-
2. Detailed Portfolio Discussion cused on the development of carbon nanotube fi-
bers leading to the development of wet and dry
2.1. Summary Description spinning techniques to produce these fibers. Re-
The Nanotechnology Roadmap is broken down search at Nanocomp Technologies has led to the
into four major themes – Engineered Materials development of a vapor phase synthesis method
and Structures, Energy Generation and Storage, to produce large quantities of carbon nanotubes
Propulsion and Electronics, Sensors and Devices (single and multiwall) which can be spun into fi-
(Figure 3). A description of each of these themes bers or processed into large sheets. However, the
follows. tensile strength and modulus of these fibers are
2.2. WBS Description far from predicted values. Wang and co-workers
at Florida State University have developed post-
2.2.1. Engineered Materials processing techniques for carbon nanotube sheets
A detailed roadmap for the development of to achieve composite strengths 30% higher than
nanostructured materials is shown in Figure 4. conventional epoxy based CFRPs. Further im-
The roadmap is broken down into five topics – provements in processing to align the nanotubes
Lightweight Strucutres, Damage Tolerant Sys- as well as methods to increase nanotube-nano-
Figure 3. Technology Area Breakdown Structure for Nanotechnology
TA10-8 DRAFTFigure 4. Engineered Materials and Structures Roadmap
tube interactions are expected to lead to SWNT ments in lightweight metals. Hierarchically nano-
based fibers with tensile strengths as high as 40-60 structured aluminum exhibited enhanced yield
GPa by 2030. For example, research by Kumar at strength and elongation relative to convention-
Georgia Tech has demonstrated that carbon fibers ally engineered aluminum. Carbon nanotube re-
produced by carbonization of gel spun SWNT/ inforced aluminum nanocomposites had signifi-
polyacrylonitrile (PAN) nanocomposites can have cantly greater hardness than unalloyed aluminum
tensile strengths 50% greater than carbon fibers and tensile strengths approaching those of steel at
produced from PAN. This improvement in tensile a fraction of the mass.
strength is attributed to the high degree of align- 2.2.1.2. Damage Tolerant Systems
ment of the nanotubes within the PAN fiber. In- Improvements in the durability and damage tol-
creases in tensile strength by a factor of two are erance of polymers and composites have been re-
projected by 2013 due to a high investment in this alized through the addition of carbon nanotubes,
area by other federal agencies. Kumar has recently graphene, and organically modified nanoclays.
shown that it may be possible to use this approach Miller has shown that addition of 5 weight per-
to produce porous carbon fibers with properties cent clay to a commercial toughened epoxy leads
equivalent to intermediate modulus carbon fi- to a two-fold increase in its notched Izod tough-
bers but at one-half the density. With improve- ness. Recent work by Wardle at MIT and others
ments in processing, including methods to pro- has demonstrated that use of “fuzzy fibers”, pro-
duce these fibers in high volume with consistent duced by the growth of carbon nanotubes onto
quality, they should be at TRL 6 by 2019. Direct the surface of commercial carbon fibers, can lead
substitution of these fibers in place of convention- to enhanced toughness and damage tolerance in
al intermediate modulus carbon fibers should en- composites. Some issues have been noted with the
able the development of 30% lighter carbon fiber poor carbon nanotube/carbon fiber adhesion and
reinforced polymer composites by 2022. Nano- further work on methods to deposit catalysts onto
technology can also lead to significant improve-
DRAFT TA10-9the fiber surface and post processing methods is 2.2.1.4. Adhesives
needed to address this. The development of robust Strong electrostatic forces (van der Waals’ forc-
“fuzzy fibers” should lead to a two-fold improve- es) cause carbon nanotubes to agglomerate. These
ment in the interlaminar toughness of composites forces have been exploited to give rise to revers-
by 2020. Self-sensing and self-healing nanocom- ible adhesion, similar to that found on the feet
posites based upon nanotubes and self-assembled of Gecko lizards. Nanotube arrays deposited onto
materials are also expected to be available by 2030. various substrates and micro/nano features give
Increased toughness in ceramics has been realized rise to surfaces that have shear and normal adhe-
using nanoscale features similar to those found in sion to a variety of substrates. This characteristic
nacre, the material that comprises sea shells. Fur- could prevent catastrophic failure in climbing ro-
ther development of this concept should make it bots and could enable the development of self-
possible to enhance the toughness of conventional healing adhesives. Methods to scale up surface en-
ceramics by a factor of 1000 by 2030. gineering of nanoscale features onto large surfaces,
Inclusion of boron based nanomaterials such as well as techniques to study their long-term du-
as boron nanotubes, boron nitride nanotubes or rability are necessary to mature these adhesives to
boron carbide nanoparticles into polyethylene or TRL 6.
other high hydrogen content polymers can en- Sealants and adhesives tend to harden and lose
hance their ballisitic toughness and enable the de- their flexibility at lower temperatures where their
velopment of multifunctional structural compos- elastic properties are necessary for adhesion, seal-
ites that provide enhanced radiation protection ing and durability. The toughening of polymers
and micro-meteoroid impact damage tolerance. through the addition of nanoscale fillers is fairly
Current production of boron and boron nitride well known and should be readily applicable to
nanotubes is on the laboratory scale and invest- develop cryogenic sealants and adhesives by 2021.
ments in methods to scale up production as well Adhesives that can tolerate temperatures in excess
as functionalization chemistries to improve the of 400°C are needed for propulsion structures and
mechanical properties of boron nitride or carbide thermal protection systems. Addition of organi-
nanoparticles should enable the development of cally modified clays and other inorganic nanopar-
multifunctional radiation shielding materials by ticles, such as POSS, have been shown to improve
2024. the oxidative stability of polymers. Inclusion of
Metamaterials possess both a negative refrac- these fillers into conventional adhesives as well as
tive index and negative dielectric constant, en- using them as the building blocks for new adhe-
abling wavelength shifts in these systems mak- sives should enable the development of ultra-high
ing them useful for electromagnetic interference temperature adhesives by 2022.
shielding. The ability to manipulate materials at
the nanoscale will open the design space for ma- 2.2.1.5. Thermal Protection and Control
terial compositions that yield this unusual prop- Enhancements in the thermal conductivity
erty. Integration of these materials into load bear- of materials, in particular polymers, have been
ing structures will impart magnetic properties and shown through the addition of carbon nano-
offer a mechanism for integrated vehicle health tubes and graphene. Theoretical studies have in-
monitoring and damage repair. dicated that incorporation of “fuzzy fibers” into
polymer matrices can lead to enhanced through
2.2.1.3. Coatings the thickness thermal conductivity of these ma-
Nanocomposite coatings can extend the life of terials. Nanostructured materials with composi-
materials at high temperatures by providing a bar- tions known to have high bulk thermal conduc-
rier to oxidation and can improve the wear resis- tivity may provide a path for nanocomposites with
tance of materials. Nanotexturing of surfaces can thermal conductivities twice that of diamond by
significantly alter their activity and impart super- 2025. These nanocomposites could find applica-
hydrophobic characteristics, reduce drag or mini- tion in lightweight radiators and heat exchangers
mize the accretion of ice, dust, and insect contam- for vehicles and habitats and could also be used
ination. Large scale texturing methods need to be for thermal management in electrical circuits and
developed and the long-term durability of these spacecraft busses. Control of thermal expansion in
nanoscale features must be evaluated before these composites used in satellites and antennae is crit-
coatings can be utilized in NASA missions. This ical since thermally induced expansion and con-
technology is expected to be mature by 2017. traction of composite structures can lead to distor-
TA10-10 DRAFTGrand Challenge – Reduce the Density of Composites by 50%
Replacement of conventional carbon fiber reinforced com-
posites with advanced nanotechnology based composites
that weigh half as much but have equivalent or better proper-
ties could reduce the dry weight of aircraft and spacecraft by
more than 30%. Ijima’s discovery of carbon nanotubes in 1991
opened up the promise of developing materials with 100 times
the strength of steel at one-sixth the weight. Despite a consid-
erable amount of research and progress in carbon nanotube
based materials, this promise has yet to be realized.
A comparison of the specific strength and stiffness of carbon
nanotubes with various aerospace materials is shown in Figure
5. The large gap between properties of carbon fiber reinforced
polymer composites (CFRP) and single wall carbon nanotubes
(SWNT) supports a focused investment in this game changing
Figure 5. A comparison of the mechanical proper-
technology. Recent work by Kumar at Georia Tech suggests
ties of SWNT with various aerospace materials.
that it is possible to develop nanotube reinforced porous car-
bon fibers with high strength and stiffness at one-half the density of intermediate modulus fibers. Use of these fibers as a di-
rect replacement for conventional intermediate modulus fibers could reduce the density of composites by as much as 30%. High
strength nanoporous polymers and polymer-inorganic hybdrids have been developed by NASA that have densities less than half
that of monolithic polymers and good compressive strength and stiffness. Use of these as in place of conventional polymer ma-
trixes has the potential to further reduce composite density to one-half that of conventional composites. Alternative processing
methods that produce nanocomposites with morphologies and interfaces tailored for optimum properties will enable further
weight reductions.
Several technical challenges must be overcome – a better understanding of the effects of processing conditions on the alignment
of nanoparticles in a given material must be gained in order to develop nanotube reinforced polymers and nanoporous polymers
with optimized properties, this understanding will also enable the development of robust, repeatable manufacturing methods
to produce these mateirals in large scale and with good batch to batch consistency. The damage tolerance of these materials
must be assessed to determine the effects of nanoporosity on properties and durability. Robust multiscale modeling techniques
capable of predicting material response and failure are needed as well as design tools to develop concepts that fully utilize the
benefits of nanostructured materials. NASA investment in this area, leveraged with investments in carbon nanotube production
and carbon fiber development by other Federal agencies and the new NNI Signature Initiative in Nanomanufacturing would ac-
celerate the development of this technology and make the promise of ultralightweight, high strength materials a reality.
tions that can negatively affect pointing accuracy. a path for lightweight, extreme temperature struc-
Addition of carbon nanotubes and graphene has tural materials that can change the design space
also been shown to reduce the coefficient of ther- for thermal protection systems significantly, en-
mal expansion in composites. abling structural concepts not available previously.
Char formation and stabilization is important Flexible aerogels, either all polymer or polymer-
for ablative materials used in rocket nozzles and inorganic hybrid, have been developed with ther-
thermal protection systems, since the char acts mal conductivities below 20 mW/m°K. These ma-
as thermal protection of the underlying ablative terials could find use as insulation in EVA suits,
material. If the mechanical integrity of the char conformal insulation for cryotanks and habitats
is poor, it can spall off and lead to high erosion and as part of a multilayer insulation for inflatable
rates for these materials. Reducing spallation or decelerators for planetary entry, descent and land-
erosion of the char can enable use of less ablative ing. Current efforts to develop high volume meth-
materials thereby reducing nozzle or TPS weight. ods to produce these materials as large area broad-
Addition of carbon nanotubes and nanofibers has goods will help mature this technology to TRL 6
been shown to improve the mechanical integri- by 2015.
ty of polymers and could be utilized to develop 2.2.1.6. Key Capabilities
nanocomposite thermal protection systems that Key capabilities enabled by developments in
are half the weight of conventional carbon-pheno- nanostructured are shown in the Table below.
lic ablators. Nanostructured carbides can provide
DRAFT TA10-112.2.2. Energy Generation and Storage surprising that there can be major advantages in
A detailed roadmap for the development of nan- using materials that are designed and built from
otechnology for energy generation, storage and the atomic level up. Some of the likely improve-
distribution is shown in Figure 6. Because energy ments will occur in applications such as batteries,
generation and energy storage rely heavily on pro- fuel cells, ultracapacitors, photovoltaics, flywheels,
cesses that occur on the molecular level, it is not energy harvesting, and energy distribution. There
Capability/Sub-Capability Mission or Roadmap Current State of Time to
Enabled Practice Develop
30% lighter, low permeability composite cryotanks: Enabled by low permeability, Exploration, Science Lightweight aluminum 5-10 years
damage tolerant nanocomposites reinforced with high strength and stiffness carbon alloys or composites,
fibers and nanosheet fillers and by the use of durable, multifunctional polymer or multilayer insulation
polymer reinforced aerogels that can function as part of the tank structure. with sprayed on foam(as
needed)
50% lighter damage tolerant structures: Enabled by high strength, high modulus Human Exploration, Carbon fiber reinforced 5 – 15 years
fibers and concepts that take advantage of mechanical properties offered by: (1) Aeronautics, Air and polymeric composites,
nanostructured materials such as nanotube based fibers and nanoparticle tough- Space vehicles lightweight alloys
ened matrixes with 10X the specific strength over current materials, (2) approaches
beyond substitution of conventional CFRP processing methods (3) ultralightweight,
durable insulation materials such as aerogels or other nanoporous materials to reduce
cryopropellant boil off, and (4) hierarchically nanostructured aluminum and nanotube/
aluminum composites for improved mechanical properties.
Extreme environment operations: Improved durability and operational capabil- Human Exploration, Si-Ge, SiC, and GaN 6-10 yrs
ity of materials, structures, power systems and devices in extreme environments, Science, Aero Vehicles, electronics, FPGAs, radia-
including radiation, dust, high and low temperatures. Use of nanoscale additives, Communications and tion tolerant foundries;
nanostructured coatings, self-assembly and self-healing to enhance durability at high Navigation functional redundancy
and low temperatures; nanoengineered surfaces with tailored surface activity for dust
mitigation; and nanoscale boron nitride/carbide and hydrogen filled nanostructures
for radiation shielding. Nanoelectronics are inherently radiation resistant (small target
cross-section) – or can be made radiation tolerant (tens of giga rads) without special
processing/fabrication methods; vacuum nanoelectronics components are radiation
insensitive and high temperature tolerant (>700 C). This also applies to sensors based
on nanomaterials.
Efficient EVA operations: Reduced mass (as much as 50%) and improved functional- Life Support and Suit construction 10 years
ity of EVA suits through a combination of lightweight multifunctional materials (struc- Habitation includes durable fabrics,
ture, radiation and MMOD protection, thermal insulation), lightweight energy storage, lightweight metals and
and energy harvesting/scavenging (conformal solar cells, piezo- and thermoelectric composites. Batteries
devices), and embedded sensors and actuators). used for energy storage.
Magnesium hydroxide
canisters used for air
purification.
Damage tolerant, multifunctional habitats: Reduced habitat mass, and enhanced Life Support and None 10-15 years
damage tolerance, durability and functionality through the use of multifunctional Habitation
structural materials (radiation and MMOD protection, thermal insulation), embedded
nano-based distributed sensing (to locate the defect), electronics and logic (to deter-
mine the corrective action) and self-healing/actuation (to implement the corrective
steps).
Adaptive Gossamer structures: Concepts for adaptive gossamer structures can be Exploration, Science IKAROS sail uses poly- First use:
enabled by lightweight, high strength fibers with low creep to yield thin, compliant, imide film and thin film 5-10 years,
reconfigurable and stowable structures. Nanoengineering to reduce membrane CTEs solar cells. Size = 50 m
and raise specific heat is desirable. Embedded sensing for localized measurements
of strain and temperature is required, as well as self-metallizing membranes for large Full poten-
gossamer structure reflectors. Tunable properties such as reflectivity, emissivity, tial 15-20
absorptivity and CTE support system control to maximize momentum. High strength years
conductive fibers enable tethers supporting solar sail propulsion
Thermal Protection and Management: Reduce mass and improve effectiveness Scientific Instruments, Carbon phenolic TPS, First use:
through: (1) 50% lighter TPS by precise nano-scale control of material pore sizes, ther- Sensors, Human aluminum radiators and 5-10 yrs
mal scattering sources for increased thermal resistance and mechanical properties; Exploration systems, straps, heat pipes
(2) durable, structural aerogel insulation with thermal conductivity < 20mW/m°K; (3) Robotic systems,
lightweight radiators and thermal distribution systems using fibers 1-100 nm in diam- Power and Propulsion Full poten-
eter (e.g., carbon nanotubes, high temperature nanofibers, ceramics) with thermal systems, aeroshells tial: 15-20
conductivity as high as 2000 W/m°K ( > diamond) (rigid and inflatable) yrs
for Entry, Descent and
Landing
“Smart” airframe and propulsion structures: Reduced mass by taking advantage N+3 SFW concepts, Aluminum alloys and First use:
of inherent multifunctionality offered by nanomaterials to enable damage tolerant Launch Structures carbon fiber reinforced 10 yrs
structural skin with embedded and distributed sensing permitting the detection and polymer composites.
repair of cracks. “Smart skin” can respond to external stimuli such as aerodynamic Sensors and wiring add
loads and reconfigure to enhance laminar flow and reduce drag. Functionality such as significant parasitic Full poten-
vibration dampening can also be incorporated to enhance acoustic properties. Highly weight. tial: 15-20
conductive skins can enhance damage tolerance to lightning strike damage. yrs
On-board Life Support Systems: Due to the high surface area and thermal con- Human Health and None for long duration 5-10 yrs
ductivity, carbon nanostructures can be used as the next generation of surfaces for Support Systems human space flight
absorption and de-absorption of atmospheric constituents (e.g. CO2) for air revitaliza-
tion. Additionally, engineered nano-particles can be used very effectively to remove
contaminants from water and for recycling/recovery. Electrospun nanofibers for tissue
engineering and regenerative medicine provide options for astronaut health manage-
ment.
TA10-12 DRAFTis a strong need for future NASA missions to have to 140 W/kg upon further work in the area of op-
enhanced energy storage methods, especially as timized catalyst chemistries, better materials, and
missions become longer and more self-contained. better reliability. Nanotechnology promises to al-
High-efficiency power storage and distribution low electrodes to provide greatly increased surface
and thermal energy conversion for space power area and membranes with higher strength and
also become more important for future missions. lower ohmic resistance. This is believed to increase
These missions can be enhanced by utilizing pow- specific power past 800 W/kg.
er systems that minimize mass, improve reliability, Improvements in flexible, organic photovoltaics
and improve life capability to up to 10,000 hours. can be achieved through the use of carbon nano-
tubes to improve charge transport and quantum
2.2.2.1. Energy Generation structures (dots and rods) to harvest more of the
There are many examples of current nanotech- solar spectrum. These technologies are expected to
nology projects related to advanced energy tech- lead to the development of conformal, radiation
nologies. For example, nanotechnology is forming hard photovoltaic materials with efficiencies in ex-
the basis of a new type of highly efficient pho- cess of 50% by 2030. These improved solar cells
tovoltaic cell that consists of quantum dots con- could be incorporated into the outer structure of a
nected by carbon nanotubes. There could even be habitat or rover and provide an additional source
structural photovoltaic materials, where the struc- of power to charge on-board batteries.
ture of a habitat could also serve as a photovoltaic
power generator. For solar energy, nanomaterials 2.2.2.2. Energy Storage
can make solar cells more efficient and more af- Using nanotechnology, future generations of
fordable. The efficiency of solar energy conversion energy systems can provide significant advanc-
and of fuel cells is expected to double. es in terms of functionality, application and ca-
Proton Exchange Membrane (PEM) fuel cells pacity. The weight of the Astronaut’s Extravehicu-
provide the promise for future specific power up lar Activity (EVA) suit could be reduced by 30%
Figure 6. Detailed roadmap for energy generation, storage and distribution.
DRAFT TA10-13Grand Challenge - Structures with Integrated Energy Generation and Energy Storage
(2017-2022)
Significant progress is currently being made in the areas of energy generation and energy storage
using nanotechnology. The extremely high surface area and high reactivity of nanomaterials al-
lows for power and energy densities far above that of conventional materials. One step forward
in the field of energy related nanotechnology is to integrate multiple systems together allowing
for an overall mass savings greater than each individual component could achieve on its own.
The development of high efficiency organic/polymer photovoltaics would enable the produc-
tion of conformal solar cells that could be incorporated into the exterior of a habitat or rover to
provide auxilliary power. Developments needed in this area include functionalization chemsitries
to allow incorporation of carbon nanotubes into these devices to enhance energy transfer and
their use in the development of flexible, transparent nanotube or graphene electrode materials.
Incorporation of quantum dots or structures will lead to a broader use of the available solar spec-
trum. Methods to enhance the radiation tolerance of these devices and nanoengineered coat-
ings to prevent dust accumulation are also needed. Flexible, safe lithium ion batteries could also be incorporated into EVA suit
garments or habitats leading to signficant weight savings. The development of new, flexible solid polymer elecrolytes with the
capability of operating at temperatures as low as -60°C could be enabled through the use of self-assembly processes, nanoporous
polymers and nanoscale additives. Improvements in the electrochemical efficiencies of these batteries could be achieved through
the development of high surface area electrode materials. The integration of both energy generation and subsequent energy stor-
age allows for greatly reduced overall mass, helping to enable new long-duration missions that need additional power.
and the Personal Life Support System (PLSS) by 2.2.2.4. Key Capabilities
50% through the use of advanced, lightweight Key capabilities enabled by nanotechnology de-
nanomaterials and lighter weight improved bat- velopments in energy generation, storage and dis-
teries. In the areas of fuel cells and photovolta- tribution are shown in the Table below.
ics, the prediction is to increase fuel cell MEA en-
ergy density and radiation hardened efficiency by 2.2.3. Propulsion
50% by 2015. Nanotechnology use in battery de- A detailed roadmap for the development of
velopment for in situ exploration is expected to propulsion related nanotechnologies is shown in
reduce overall weight by 30% within this decade. Figure 7. This theme is further subdivided into
For batteries, high capacity bulk materials pose a Nanopropellants, Propulsion Components and
critical challenge to long lifetime due to large vol- In-Space Propulsion. A discussion of each of these
ume changes to the host material as a result of Li topics follows.
insertion and extraction. The goal for supercapac- 2.2.3.1. Nanopropellants
itors or ultracapacitors with nanotechnology is to Depending upon their size and surface rough-
provide up to five times the power density of to- ness, nanoscale particles can have surface areas in
day’s materials. In the near term, nanostructured excess of 2000 m2/gram, roughly one-third the
electrodes are providing advances for lithium ion area of a football field. This high surface area gives
batteries. rise to high surface reactivity, and the ability to
2.2.2.3. Energy Distribution adsorb large quantities of liquids or gasses. A re-
Use of lightweight, low gauge carbon nanotube search team at Purdue and Penn State has demon-
wire in place of conventional copper wire can sig- strated that a slurry of nanoscale aluminum in ice
nificantly reduce the weight of power distribu- provided enough thrust to propel a small rocket
tion systems in vehicles, habitats and EVA suits. to a height of 1300 ft. Addition of nanoscale par-
In addition, nanotube wires do not corrode and ticles (metals and aerogels) has been shown to gel
are more ductile than copper thereby leading to liquid hydrogen and hydrocarbon jet fuels. These
more durable and safer wiring. Lightweight car- nanopropellants have better handling characteris-
bon nanotube wires and electrical cables have tics than conventional cyrogenic propellants and
been demonstrated by Nanocomp. Testing the are less toxic than hypergolic fuels. However, in
long-term durability of these cables, in particu- order for these materials to be suitable propel-
lar under simulated space environments, are nec- lant replacements, passivation chemistries must
essary to raise this technology to TRL 6 by 2016. be developed to prevent premature oxidation of
the nanoparticles and synthesis methods, includ-
ing self-assembly based techniques, are needed to
TA10-14 DRAFTCapability/Sub-Capability Mission or Roadmap Current State of Time to
Enabled Practice Develop
Efficient EVA operations: See Lightweight Structures. Life Support and
Habitation
Power/Energy Storage: Materials and devices for energy storage and power delivery Broad range of Explora- Nafion proton ex- First use:
depend significantly on the surface area available for charge transfer. Nano-scale mate- tion, Science missions change membranes for 5-10 yrs
rials (e.g. carbon nanotubes, nanorods) have >1000X greater areas than any convention- fuel cells, Li-batteries
al material: 50% more efficient proton exchange membrane fuel cells utilizing carbon (Grand Challenge: Nanopropellants - From the Test Tube to Practice Conventional cryogenic propellants present technical challenges in handling, storage and distribution. Cryogenic propellant tanks must be insulated often times resulting in the addition of parasitic weight to the vehicle. Long-term storage of cyropropellants also requires the use of cryo-coolers to limit boil-off which can also add weight to the vehicle. Compatibility and reactivity issues limit the materials that can be used for liquid oxygen storage and transfer. Currently available alternatives, such as hypergolics, are toxic and re- quire special handling. Recent developments by a team of researchers at Penn State and Purdue Universities have demonstrated the feasibility of using nanoscale energetic materials, in this case a slurry of nanoscale aluminum particles in ice (ALICE), as propellants. In this first demonstration, a small ALICE powered rocket was able to reach a height of 1300 feet. Significant technical challenges remain, however, before nanopropellants such as these can be used in NASA missions. Nanoscale metal particles are highly reactive materials. While this is desirable for propel- lants, it can create safety hazards. In addition, these particles are highly susceptible to surface oxidation which adds unneeded weight, as much as 20%, to the particles and reduces their specific thrust. Passivation techniques, such as functionalizing surface of the nanoparticles with organic groups can reduce suscepti- bility to oxidation and increase safety, however the proper functionalization chemistries must be identified that do not inhibit combustion. Manufacturing methods must be developed not only to scale up produc- tion of these materials, but also to develop ways to control the size and morphol- ogy of the nanoparticles and influence their burning behavior. Novel fabrication Figure 8. Photograph of an ALICE methods will enable the syntheis of core-shell nanoparticles with different metals powered rocket prior to its suc- in each layer of the nanoparticle which could be tailored to create particles with cessful flight on August 7, 2010 highly controlled burn rates and energies. Currently NASA is collaborating with (S. Son, Purdue University). other government agencies to mature this technology. new high performance carbon fibers is expected would be replaced with lightweight electric mo- to enable the development of composite cryotanks tors that are powered either by turbines or fuel that are 30% lighter and more damage tolerant cells. Such an approach would lead to significant than today’s tanks. noise reductions. High conductivity carbon nano- Use of nanostructured materials in aircraft en- tube wires with high current capacity, expected to gines can improve their performance and dura- be available by 2016, could enable the develop- bility. The high temperature stability of fiber re- ment of lightweight, high horsepower electric mo- inforced polymer composites can be enhanced by tors and could also be used in the wiring cables for as much as 25% through the addition of small power distribution. In order to mature this tech- amounts of nanoclays. This enables the develop- nology, scale-able methods for producing carbon ment of fan and compressor components with nanotube wire with the right current carrying ca- better long-term durability. Conventional com- pacity must be developed. There has been good posites have recently been introduced into the fan progress in this area. Nanocomp Technologies Inc. containment system for the GENeX engine that has developed a method to produce carbon nano- is powering the Boeing 787, leading to weight re- tube wires and has demonstrated them in a small, duction of over 300 lb per engine. Further reduc- lightweight electric motor to cool electrical com- tions in containment system weight could be en- ponents and has also developed nanotube based abled by the use of advanced carbon fibers and wiring cables. tapes to develop composites with improved im- 2.2.3.3. In-Space Propulsion pact resistance. Improvements in engine perfor- Micropropulsion subsystems are critical to en- mance could be achieved through the incorpora- abling small satellite capabilities in formation fly- tion of “smart” adaptive composite materials in the ing, precision pointing, proximity operations, inlet to tailor air flow and in adaptive fan blades drag-make-up, autonomous swarm operations, with switchable pitch and camber. This technol- orbital (and de-orbital) maneuvers, and for gen- ogy, expected to be available by 2032, would re- eral spacecraft attitude control. The key properties quire advances in low density, high strength com- for a micropropulsion subsystem include its total posites as well as adaptive fibers and textiles. New wet mass and volume, min/max/avg power usage, concepts in turboelectric propulsion are being de- and total impulse capability. For small satellites, veloped in which conventional aircraft engines especially for Femtosats (total mass 100 g), nano- TA10-16 DRAFT
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