Research On The Design Of Tiny Amounts Of Lunar Regolith Sampler Based On Electrostatic Adsorption

This paper aims at the sampling missio n o f the tiny amounts of lunar rego lith,and the task requires that the amount of lunar so il co llected should be controlled at the level of milligram,so as to meet the demand o f single sample analysis fo r scient ific instruments.Scient ific instruments are carried on the lander to facilitate lunar so il emplacement analysis and ensure the scient ific nature o f lunar so il analysis data.At present,the sampling vo lume of tradit ional mechanical sampler is usually above the magnitude of gram,which makes it difficult to sample the tiny amounts of lunar rego lit h,and the available resources of sampler are limited.In view o f the design difficult ies of the sampler,this paper proposes a kind of tiny amounts o f lunar rego lith sampler based on electrostat ic adsorpt ion,which can realize the absorption and co llect ion o f lunar rego lith through the electrostat ic force of the electrode,and contro l the mass of absorbed lunar rego lith by changing the adsorption area of the electrode and the excitation vo ltage.The force of single lunar part icles in electrostat ic field is analyzed to reveal the mechanism o f lunar rego lith adsorpt ion.Taking the who le lunar rego lith layer as the research object,the electrostatic adsorption model o f single electrode t ype I,t ype II and coplanar bipolar electrode was established,and the electrostat ic force in the model is calculated by using Coulomb’s law and virtual work principle.On the premise that the dielectric propert ies between the lunar rego lith layer and the electrode are uniform,the electrostatic forces of the three electrodes are co mpared,and it is confirmed that the single electrode has the best electrostat ic adsorption performance o f II propert y.To determine the reasonableness of Maxwell stress equivalent to stat ic pressure,the electrostatic simulat ion module of COMSOL is used to carry out the simulat ion calculat ion o f stat ic forces o f single electrode t ype I,type II and coplanar bipo lar electrode.By co mparing the static forces of the three electrodes,the opt imal electrode configurat ion was determined.The simulat ion analysis o f the coplanar bipo lar electrode parameters and the centrifugal test o f electrostat ic adsorption particles are carried out to further determine the relat ionship between the coplanar bipo lar electrode parameters and the electrostatic force o f the electrode,which is a reference for the optimizat ion of the electrode.Two t ypes of electrostat ic adsorpt ion samplers were designed in co mbinat ion with the engineering missio n object ives and the electrostat ic adsorpt ion characterist ics o f the electrodes.The drilling tool configurat ion o f the sampler type I can adapt to the sampling environment o f the co mplex terrain o f the extraterrestrial bodies.The sampler II has a flat front design for easy electrode placement.In order to verify the rat ionalit y o f sampler t ype I drilling too l configurat ion design and determine the suitable drilling procedure,a large number of lunar regolit h simulat ion samples are prepared for drilling experiments,and sampler drilling tests are carried out under different procedures.The feasibilit y o f the sampler’s electrostat ic adsorpt ion method is verified by weighing the amount of lunar soil absorbed by the sampler.In conclusio n,this paper determined that the single electrode t ype II electrostat ic adsorption performance is the best,and through experiments to verify the sampler’s sampling vo lume to meet the requirements o f milligram magnitude,which also to prove the feasibilit y of contro lling the vo ltage to change the amount of electrostat ic adsorpt ion.The electrostat ic adsorption sampler designed in this paper so lves the problem that the sampling amount of the tradit ional sampler is too large and the engineering problem that the sampling amount cannot be contro lled,which also provides a new sampling technology for the sampling o f extraterrestrial bodies.