Nanoparticle field extraction thruster (nanoFET): Introduction to, analysis of, and experimental results from the "No-liquid" configuration AIAA-2008-5097
This paper introduces a nanoparticle field extraction thruster (nanoFET) concept that does not depend on the liquid delivery of micro and nano-particles for extraction and acceleration. The no-liquid approach potentially provides important advantages such as allowing the use of smaller particles for propellant, which may offer a greater specific impulse. The most likely developmental obstacles are the adhesion of the particles to the source electrode and the cohesion between the particles. Adhesion and cohesion models are presented along with proposed methods of overcoming each. A method of using the applied charging electric field to overcome the adhesion force is investigated, which predicts that it may be possible to remove particles with diameters down to hundreds or even tens of nanometers from a planar electrode with only the application of a high strength electric field. To investigate this particle removal model, eight test cases, involving 4 particle sizes and 2 electrode materials, are presented. A method of transporting the dry particle propellant through an ultra-fine sieve prior to the charging and accelerating stages is investigated as a method of overcoming the cohesion between the particles. A simple proof-of-concept experiment is presented which indicates that this method is capable of breaking the cohesion force under appropriate conditions, which helps to guide future research. © 2008 by The University of Michigan.
