NIAC Poster

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Contents

Text for poster for October kickoff conference

When we are done, we will transfer this to powerpoint and print it on a 3'x4' single sheet of paper.

(Link to the main project page)

Title slide: Aerospace Products from Nanoscale Modules

Our names, maybe a logo, other intro info.

Problems in Space Flight...

  • Risk
    • Engineering near the edge of performance
    • Mid-mission failures hard to repair
  • Cost
    • Weight / fuel
    • Construction cost
  • Difficulty of developing new designs
    • Cost of R&D (engineering time, build time, money)
    • Risk, especially for manned missions
  • Old hardware on long missions
    • Obsolescence
    • Reliability

...Mitigated by general-purpose nanoscale manufacturing systems.

  • On the ground
    • Cheaper, faster build (by orders of magnitude)
    • Very rapid prototyping
    • Lower cost of failure
    • High performance materials and systems
  • In flight
    • Build what you need, when you need it
    • Bring along a little feedstock instead of many different replacement parts
    • Less redundancy/reliability needed on repairable systems
    • Build improved designs not available at start of mission

Manufacturing technologies

Fabrication

  • Mechanosynthesis
    • Mechanically guided covalent chemistry
    • Simple machines inject complexity from computer control
    • Expectation of extremely high precision/reliability (covalent chemistry is digital)
    • Diamond-lattice fabrication may require as few as 5 reactions
    • Should be autoproductive
  • Bulk chemistry plus self-assembly
    • Polymer-building sequence can inject some complexity
    • Biopolymers are somewhat understood
    • May be usable without nanoscale machinery

Assembly

  • Self-assembly
    • Hard to get enough complexity
    • Weak joining?
  • General-purpose robotic assembly
    • Requires lots of special-case per-product path planning
  • Convergent assembly
    • Small blocks joined to make bigger blocks, through several levels
    • Makes blocky products (which can then unfold or inflate)
  • Working-face aggregation
    • Add nanoblocks directly to product
    • Even sub-micron blocks can grow at meters/hour
    • Can build sparse products

Materials and capabilities

  • Mechanical
    • Excellent strength and toughness, per mass and per volume
    • High-bond-density, anisotropic materials can have strength approaching theoretical max (not limited by defects)
    • Mechanical joints can preserve ~50% strength
  • Optics
    • Diamond is clear; graphite is opaque
    • Regular sub-wavelength structures are invisble; irregular structures are a hologram
    • Color (butterfly wing)
  • Electrics, electronics
    • Diamond is an insulator; fullerenes are conductor, semiconductor, insulator
    • Networks can use coax, or maybe optical fiber
  • Energy conversion
    • Motor power density inversely proportional to size: electrostatic motors 10^9 W/cm^3
    • Chemoelectric (fuel cell): 10^14 W/m^3?
  • Sensors (many kinds, very small and sensitive)
  • Digital logic (mechanical: very compact; very efficient by today's standards)
    • (Assuming straightforward use of reversible logic: Earth Simulator in 2 W)
  • Nanometer-scale features (~10^24 components/m^3)
  • Seals
    • Butted N-terminated diamond should exclude helium
    • Research Question: Reactivity
  • Chemical binding and manipulation
    • Sorting, filtering
    • Mechanosynthesis
    • Microfluidics (beyond the scope)
  • Mechanosynthetic manufacturing
    • Scaling laws: Operation time ~ size
    • A billion-atom mechanosynthesis robot (~200 nm) might duplicate itself in hours
  • Thermal
    • Diamond and some buckytubes are excellent heat transporters
    • Someone just told me that some buckytubes don't transport heat--structure reflects phonons 90 degrees
    • Vacuum gaps are easier with strong materials
      • How to silver the surfaces?
      • Maybe use micro-patterning (as seen in recent light bulb tech) to reduce IR emission?

Components

  • Structure
    • Convert all stress to tensile stress: structural pressure tanks, fractal trusses
    • Research Question: Specifying and building large-scale and multi-scale structures
  • Actuators: controllable rotation and deformation
    • Research Question: Mechanical designs for these
  • Computers (architecture is straightforward)
    • Computer density varies as cube of size: nm features implies Earth Simulator in a mm^3
  • Fault tolerance
    • Materials (flaw/damage resistance through anisotropy)
    • Mechanisms (friable links?)
    • Logic (voting between computers)
    • Simple redundancy (e.g. 9-for-8) at multiple levels appears best
  • Displays
  • Antennas
  • Chemical processors
  • Specialized propulsion hardware
    • Fast electrics or mechanics for mass driver
    • Research Question: Surfaces and volumes for hot reactive gas (rockets, jets)

Summary: Nanofactory

  • Tabletop, self-contained, automated, general-purpose, nanoscale manufacturing
  • Can use any of several nanoscale fabrication methods
  • Can produce high-performance kilogram-scale products in ~hours
  • Should be autoproductive (build duplicate nanofactory on command)

(Insert nanofactory picture)

Products to build

Macro-scale components

  • Compact motors
  • Powerful computers
  • Lightweight structure
  • "Smart" materials with embedded computers/sensors

Integrated systems

  • Propulsion systems
    • Jets (turbo, ram, scram)
      • Can we handle the temperature?
      • Can we handle the thermal shock of cooling?
    • Rockets
      • Kerosene/H2O2?
      • Can we handle LOX/GOX without metals?
    • Mass driver
  • Structure (wing, strut, aeroshell, spacesuit shell)
    • Passive is easy(?). What about active/morphing?
  • Life support equipment (chemical processing)
    • Efficient 100% recycling? (probably "beyond the scope")

Entire products

  • Surface transporters for planetary and lunar missions
  • Air-breathing SSTO's
  • Space suits

Major research questions

Operating conditions

  • Chemical compatibility
  • Thermal limits (manufacturing process and product)

Block size and complexity

  • How can simple functions be combined?
  • How can complex blocks be designed and built?
  • Compatibility between fabrication and assembly

Detailed block design

  • Atom-level design/simulation (beyond the scope?)
  • Higher-level functional description (must be generalizable)

Macro-scale capabilities

  • Inter-block interface
    • Mechanical strength
    • Functional joints, including seals
  • Assembly of complex shapes
    • Convergent assembly: unfolding/inflating
    • Working-face aggregation appears straightforward: is it?

Estimates of overall utility

  • Weight savings (rule of thumb: how many orders of magnitude?)
  • Generality (what can't we build?)
  • Performance
    • Manufacture (speed, efficiency, difficulty)
    • Product (efficiency, compactness, reliability)
  • Design
    • How generally applicable is levels-of-abstraction design?
    • How easy will it be to design new components at each level?
    • Note: manufacture planning must be (almost) completely automated


Methods of Assembly

This was the original question of the study proposal: How can complex-shaped products be made from cubical output, as produced by Chris's nanofactory design?

Chris now thinks that working-face aggregation may make assembly simple enough that this question becomes less difficult/interesting. See "Methods of Assembly" section of the main project page.

Curves still pose interesting problems. Locally, every surface is "almost flat", but there'll be a need for non-Euclidean geometry at some points. How can nanoblocks be specified, built, handled, and assembled to form smooth curves?

Given that most macro-scale products will be mostly empty space, folding/collapsing may be a useful feature for at least three reasons:

  • Smaller manufacturing systems
  • More compact storage
  • Functional morphing (e.g. aeroshell shape-changing)

How can products fold and unfold without harmful creases?

How simple can the nanoblocks be?

Complex: A billion atoms (~200-nm cube), sufficient for multi-axis robot or 8086-class CPU, as described in "Design of a Primitive Nanofactory", http://jetpress.org/volume13/Nanofactory.htm Image:(Nanoblock)

Simple: About 5000 atoms, 3D versions of the Wang tiles in the KCA Final Report http://www.niac.usra.edu/files/studies/final_report/pdf/883Toth-Fejel.pdf and reported in more detail at Transvision '04 (Toronto, August 2004). Possible via assisted self-assembly with sticky patches? (See http://www.engin.umich.edu/dept/che/research/glotzer/documents/2004PatchyPart.pdf)

Perhaps Complex nanoblocks can be assembled more easily from Simple ones. Image:(Wang Tile)

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