1. March 19, 2007S. A. Getty NASA Headquarters ESMD Faculty-Student Research Team: Nanotechnology for Exploration and Science Dr. Stephanie A. Getty NASA GSFCCode 541 Materials Engineering Branch Applied Nanotechnology Prof. David D. Allred Brigham Young University Dept. of Physics and Astronomy Students: Jonathon Brame Johnathan Goodsell

2. March 19, 2007S. A. Getty NASA Headquarters NASA’s Exploration Initiative Courtesy NASA website To the Moon, Mars and Beyond The Vision for Space Exploration calls for humans to return to the moon by the end of the next decade, paving the way for eventual journeys to Mars and beyond. Courtesy NASA website To the Moon, Mars and Beyond The Vision for Space Exploration calls for humans to return to the moon by the end of the next decade, paving the way for eventual journeys to Mars and beyond. Carbon Nanotube- Magnetic analysis of geological based Magnetometer : samples on Mars and the Moon Orientation for manned expeditions Location of mining resources

3. March 19, 2007S. A. Getty NASA Headquarters Projects ongoing in GSFC NanoDevices Group –Strain-based NanoCompass GSFC: 541, 691 BYU summer intern team: Prof. D. Allred, Johnathan Goodsell, Jon Brame –Electron gun for miniaturized mass spectrometer GSFC: 541, 553, 699 Fisk University summer intern: Melissa Harrison –Generalized strain sensors GSFC: 541, 660 BYU summer intern team: Prof. D. Allred, Johnathan Goodsell, Jon Brame Fisk University summer intern: Melissa Harrison

4. March 19, 2007S. A. Getty NASA Headquarters Background Information: Carbon Nanotubes

5. March 19, 2007S. A. Getty NASA Headquarters Nanoelectronic Materials Single-walled Carbon Nanotubes Metallic or Semiconducting –Difficult to control  trend toward SWCNT network devices Electronic properties sensitive to deformation –Strain sensing Courtesy Smalley Group, Rice Univ.

6. March 19, 2007S. A. Getty NASA Headquarters Vapor-Liquid-Solid Growth Feedstock gas  liquid alloy  solid nanostructure SWCNTs: Catalyst = Fe(NO 3 ) 3 :IPA or thin film Fe Feedstock = CH 4 and C 2 H 4 T G = 950°C, t G = 5-10 minutes MWCNTs: Catalyst = thin film Al/Fe bilayer Feedstock = C 2 H 4 T G = 750°C, t G = 5-10 minutes

7. March 19, 2007S. A. Getty NASA Headquarters Thin Film Fe Catalyst High density Improved cleanliness TEM studies show –SWCNTs –MWCNTs –bundles T G = 950°C NanoCompass Johnathan Goodsell, Prof. David Allred, Prof. R. Vanfleet (BYU)

8. March 19, 2007S. A. Getty NASA Headquarters Summary of Progress: SWCNT Growth Johnathan Goodsell –Brigham Young University –Mechanical Engineering Major Summer project: Optimize growth of SWCNTs using thin film catalyst –New process for GSFC –Crucial for NanoCompass development Excellent results in only 8 weeks –Contributed to IEEE Nano 2006 Presentation, Cincinnati, OH, July 2006

9. March 19, 2007S. A. Getty NASA Headquarters SWCNT NanoCompass for High Spatial Resolution Magnetometry

10. March 19, 2007S. A. Getty NASA Headquarters Applications: Magnetospheric Science Spacecraft Orientation Planetary Geomagnetism but cm-scale resolution Limited materials supply Fluxgate Magnetometer: High sensitivity (nTesla) Low noise M. H. Acuna, Rev. Sci. Inst. 73, 3717 (2002) Technological Motivation Mars

11. March 19, 2007S. A. Getty NASA Headquarters NanoCompass Design ● Au Electrodes Single-Walled Carbon Nanotubes ● Ferromagnetic Needle  Mech coupled to SWCNTs  Deflected in Magnetic Field NanoCompass

12. March 19, 2007S. A. Getty NASA Headquarters Projected Specifications NanoCompass (estimated) UCLA fluxgate (ST5) Max Op Temp~450°C100°C Sensor Dimensions 10 -5 cm x 10 -5 cm on Si (scalable) 4 cm x 4 cm x 6 cm Sensor [Array] Mass 1 g75 g Sensor Op Power10 -3 - 10 -2 mW50 mW

13. March 19, 2007S. A. Getty NASA Headquarters NanoCompass Fabrication (to step 4) Materials can be robust to fabrication process Next steps: Reduce electrode spacing Reduce needle width Increase trench depth NanoCompass

14. March 19, 2007S. A. Getty NASA Headquarters Future Work: Variability in Processing SWCNT device electrically intact During magnetic field testing, continuity lost Next prototype in progress Au SWCNTs Remnant needle

15. March 19, 2007S. A. Getty NASA Headquarters Generalized Strain Sensing Using SWCNTs

16. March 19, 2007S. A. Getty NASA Headquarters Flexible substrates Parylene, PDMS are candidates –Modular electromechanical strain sensors –Modular field emitters –Application-adaptive devices Parylene: vapor-phase coated polymer, highly chemically resistant, excellent electronic insulator PDMS: polydimethylsiloxane, two-part curable elastomer, chemically resistant, good electronic insulator – to be demonstrated in SWCNTs

17. March 19, 2007S. A. Getty NASA Headquarters Device Transfer to Parylene O 2 plasma 3. Transfer to PDMS by substrate removal 1. Fabricate SWCNT device on rigid substrate to allow electrical characterization Wet etch 2. Deposit parylene

18. March 19, 2007S. A. Getty NASA Headquarters Parylene-bound SWCNT Strain Device Flexible Substrates Jonathon Brame, Prof. David Allred (BYU)

19. March 19, 2007S. A. Getty NASA Headquarters Preliminary Results Large increase in device resistance with application of strain, as expected Need to separate contact effects from piezoresistive effects Need to evaluate reproducibility The slope of the lines between 4µm stretch sets indicates that the resistance increases reversibly with increased strain. Flexible Substrates

20. March 19, 2007S. A. Getty NASA Headquarters Summary of Progress: Parylene-bound SWCNT Devices Jonathon Brame –Brigham Young University –Physics Major Summer project: –Demonstrate transfer of SWCNTs to parylene substrates –Test electromechanical response Preliminary fabrication and test completed in only 12 weeks –Publication and presentation at MRS Fall Meeting, Boston, November 2006 –“Strain-based Electrical Properties of Systems of Carbon Nanotubes Embedded in Parylene,” Jon Brame, Stephanie Getty, Johnathan Goodsell, and David Dean Allred, Proceedings, Materials Research Society Fall 2006 Meeting.

21. March 19, 2007S. A. Getty NASA Headquarters Status of Collaboration: GSFC-BYU Team BYU Team has major role in Mars Desert Research Station (UT) –In situ demonstration of NanoCompass operation –Student-operated for outreach effort –Relevant to manned missions to the Moon and Mars Joint proposal submitted to support NanoCompass: –ROSES Planetary Instrument Definition and Development –Decision Pending Building growth/characterization facility at BYU –Correlated results, independent of location, important to the CNT field –Measurements of CNT response in extreme UV planned –Possible applications in nanomaterial sensing for workplace safety monitoring

22. March 19, 2007S. A. Getty NASA HeadquartersAcknowledgements Dr. Peter Wasilewski GSFC/Astrochemistry Laboratory Dr. Louis Barbier GSFC/Exploration of the Universe Division Dr. Paul MahaffyGSFC/Atmospheric Experiments Laboratory Patrick RomanGSFC/Detector Systems Branch Barney LynchGSFC/Detector Systems Branch Dr. Federico HerreroGSFC/Detector Systems Branch Rusty JonesGSFC/Detector Systems Branch Dr. Todd King GSFC/Materials Engineering Branch Rachael BisGSFC/Materials Engineering Branch Michael BeamesderferGSFC/Materials Engineering Branch Lance DelzeitARC/Nanotechnology Branch Prof. Gunther Kletetschka GSFC/Catholic University of America Vilem MikulaGSFC/Catholic University of America Tomoko AdachiGSFC/Catholic University of America ESMD Summer Internship Program Prof. David Allred Brigham Young University/Dept. of Physics & Astronomy Prof. Richard VanfleetBrigham Young University/Dept. of Physics & Astronomy Johnathan GoodsellBrigham Young University/Mechanical Engineering Dept. Jonathon BrameBrigham Young University/Dept. of Physics & Astronomy MUCERPI Summer Internship Program Melissa HarrisonFisk University This work was supported by the Goddard Space Flight Center Director’s Discretionary Fund, the GSFC IRAD Program, the Minority University College Education and Research Partnership Initiative, and the Exploration Systems Mission Directorate Faculty-Student Summer Internship Program

23. March 19, 2007S. A. Getty NASA Headquarters Extra Slides

24. March 19, 2007S. A. Getty NASA Headquarters Nanoelectronic Materials Single-walled Carbon Nanotubes Characterized by chirality, diameter –Diameter ~ 1 nm Metallic or Semiconducting –Difficult to control  trend toward SWCNT network devices Electronic properties sensitive to deformation –Strain sensing Courtesy Smalley Group, Rice Univ. Courtesy Fuhrer Group, Univ Maryland, College Park Metallic SWCNT: n – m = 3 x integer

25. March 19, 2007S. A. Getty NASA Headquarters Nanoelectronic Materials, Cont. Multi-walled Carbon Nanotubes Exclusively metallic –Similar to graphite Diameters 30-100 nm –Larger than SWCNTs High aspect ratio with many available electrons –Field emission

26. March 19, 2007S. A. Getty NASA Headquarters E-gun for MEMS Time-of-Flight Planetary Atmospheric Science Mass Spectrometer : and biologically significant molecular species for astrobiology Ion lens assembly prototype Carbon Nanotube- based Electron Gun

27. March 19, 2007S. A. Getty NASA Headquarters Comparison: Candidate Technologies MWCNTs Spindt Emitters Thermionic Type Metric CNT Field Emitter Spindt Emitter Thermionic Emitter Density 10 10 /cm 2 *5x10 7 /cm 2† 1 /cm 2 Current @ Voltage 100μA @ 50V** 1mA @ 150 V* Operating Temp Ambient >700°C ¶ Redundancy (2mm diam) 3x10 8 10 6 1 *This work **Optimized † V. M. Aguero and R. C. Adamo, 6th Spacecraft Charging Technology Conference (2000). ¶ Barium Oxide-coated Tungsten Field Emission

28. March 19, 2007S. A. Getty NASA Headquarters CNT tower dimensions –5 μm x 5 μm x 10 μm (height) 50 μm pitch 2mm x 2mm array Field Emission Patterned CNT Cathode

29. March 19, 2007S. A. Getty NASA Headquarters Patterned MWCNTs for High Performance E-gun GSFC patterned MWCNT emitter: Cathode-grid spacing = 140 µm Turn-on voltage <100 V 50 µA @ 10 mW Compare to Cassini- Huygens thermionic e-gun: 80 µA @ 1000 mW Field Emission

30. March 19, 2007S. A. Getty NASA Headquarters GSFC:EGp2 Sample Database  Best performer: –GSFC patterned sample –50 uA @ gap = 140 um Field Emission

31. March 19, 2007S. A. Getty NASA Headquarters Side-by-Side E-Gun Evaluation Field Emission Recent and Upcoming Work: Compare candidate e-gun technologies, fully integrated with aperture/lens stack lens stack filament repeller Towards Integration into MEMS Time-of-Flight Mass Spectrometer CNT e-gunThermionic e-gun

32. March 19, 2007S. A. Getty NASA Headquarters Future Work for Summer Interns: CNT E-Gun Lifetime testing of CNT emitters Study of performance in ambient gas environment Maturation of fabrication techniques Maturation of packaging techniques Advanced electronics to develop feedback/ballast for current stabilization