Investigation of a Micro- and Nano-Particle In-Space Electrostatic Propulsion Concept by Louis D. Musinski A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Electrical Engineering) in The University of Michigan 2009 Doctoral Committee: Professor Brian E. Gilchrist, Co-Chair Professor Alec D. Gallimore, Co-Chair Professor Yogesh B. Gianchandani Associate Professor Michael J. Solomon Louis D. Musinski © ———————— 2009 All Rights Reserved Acknowledgements First, I would like to thank everyone who helped and supported me throughout my entire education. This work was made possible by everyone who has touched my life and includes people too numerous mention. To everyone who is not directly mentioned here, thank you! I would like to express gratitude for my advisor and co-chairman, Dr. Brian Gilchrist. His support over the last several years has been invaluable towards my development as an engineer and a person. The enthusiasm he exudes motivates people around him and I consider myself privileged to have worked with him. I look forward to future collaborations. I also thank my other co-chairman, Dr. Alec Gallimore, who has also provided significant guidance throughout my graduate school career. Dr. Michael Solomon and Dr. Yogesh Gianchandani, thank you for your help and guidance as members of my dissertation committee. I was fortunate to have been involved with a wonderful research group, nanoFET, which was composed of, not only excellent engineers, but also people that were a pleasure to work with. Thank you: Dr. Joanna Mirecki-Millunchick, Dr. Mark Burns, Dr. Michael Kiedar, Thomas Liu, Deshpremy Mukhija, Inkyu Eu, and David Liaw. The members of the Space Electrodynamics and Tether Systems (SETS) research group provided support, guidance, friendship, and the needed distractions that were an ii essential part my graduate school experience. Thank you: Chris Deline, Keith Fuhrhop, Rafael Ramos, Dave Morris, and Chris Davis. The Horace H. Rackham School of Graduate Studies funded my graduate studies for one year, the NASA Institute for Advanced Concepts (NIAC) provided funding for almost two years, and the Air Force Office of Scientific Research (AFOSR) provided funding for another year. The employees of the Space Physics Research Laboratory (SPRL) at the University of Michigan provided help on numerous on occasions. In particular, I would like to thank Robb Gillespie and Chuck Navarre for their help machining experimental equipment and prototypes. Lastly, I would like to thank my family for all the love and support they have given me. Thank you Mom, Dad, and Alex. Louis Musinski December 12, 2008 iii Table of Contents Acknowledgements ........................................................................................................ ii List of Figures ................................................................................................................vi List of Tables............................................................................................................... xiii List of Appendices.........................................................................................................xv Glossary .......................................................................................................................xvi Abstract........................................................................................................................xxi Chapter 1. Motivation, Background, and Introduction ...........................................................1 1.1. Motivation of Research.............................................................................1 1.2. Background of Space Electrostatic Propulsion..........................................2 1.3. Introduction to the Micro- and Nano-Particle Thruster............................10 1.4. Summary of Research Contributions.......................................................15 1.5. Dissertation Overview ............................................................................17 2. Electrostatic Charging of Spherical and Cylindrical Particles .............................19 2.1. Introduction............................................................................................19 2.2. Theory of Particle Charging....................................................................20 2.3. Experimental Setup ................................................................................50 2.4. Experimental Results..............................................................................58 2.5. Particle Charging Time...........................................................................63 2.6. Effects of Particle Charging on Micro- and Nano-Particle Thrusters.......69 2.7. Conclusion .............................................................................................70 3. Liquid Surface Instability Initiated by an Applied High Strength Electric Field..72 3.1. Introduction............................................................................................72 3.2. Liquid Instability Theory........................................................................73 3.3. Experimental Setup ................................................................................89 3.4. Experimental Results..............................................................................90 3.5. Conclusion .............................................................................................91 4. Extraction of Spherical and Cylindrical Particles From an Insulating Liquid ......93 4.1. Introduction............................................................................................93 4.2. Theory of Particle Extraction..................................................................94 4.3. Experimental Setup ..............................................................................129 4.4. Experimental Results............................................................................133 4.5. Discussion of Experimental Results......................................................137 iv 4.6. Effects of Particle Extraction on Micro- and Nano-Particle Thrusters ...140 4.7. Conclusion ...........................................................................................142 5. Adhesion and Cohesion of Dry Micro- and Nano-Particles...............................143 5.1. Introduction..........................................................................................143 5.2. Adhesion and Cohesion Forces.............................................................145 5.3. Overcoming the Adhesion Force Using High Strength Electric Fields ..155 5.4. Experimental Setup ..............................................................................165 5.5. Experimental Results............................................................................173 5.6. Variables of the Experiment .................................................................177 5.7. Lifshitz-van der Waals Constant...........................................................189 5.8. Effects of the van der Waals Adhesion Force on Micro- and Nano-Particle Thrusters.......................................................................................................191 5.9. Conclusion ...........................................................................................193 6. Dry Particle Transport......................................................................................195 6.1. Introduction..........................................................................................195 6.2. Particle Transport Using the Gradient in an Applied Electric Field .......195 6.3. Particle Transport Through Micro- and Nano-Sieves ............................222 6.4. Conclusion ...........................................................................................227 7. Conclusions and Recommendations for Future Research..................................229 7.1. Summary and Conclusions of Research ................................................229 7.2. Recommendations for Future Work......................................................235 Appendices..................................................................................................................238 Bibliography................................................................................................................248 v List of Figures Figure 1.1: Dry mass fraction as a function of V for specific impulses of 450 s and 3000 s..............................................................................................................................5 Figure 1.2: Diagram (left) and photograph (right) of the gridded ion thruster, NSTAR, used for NASA’s Deep Space 1. ......................................................................................7 Figure 1.3: Diagram (left) and photograph (right)13 of a Hall effect thruster....................8 Figure 1.4: Diagram of a single FEEP emitter.................................................................9 Figure 1.5: Diagram of a single colloid emitter. ............................................................10 Figure 1.6: Transport of 20 μm particles from a large storage reservoir through microfluidic channels.....................................................................................................12 Figure 1.7: Design of a single emitter from the insulating liquid configuration..............12 Figure 1.8: Design of a single emitter from the