Continues From: Electrodynamic Dust Shield – History
The electric curtain is composed of a series of parallel electrodes spaced a small distance apart. When an AC current is applied to the electrodes they generate an electric field, and this field accelerates charged particles, whether it be lunar dust or smog. When the electric curtain is running, current is applied to the electrodes in a successive pattern. This forms a wave of forces from the electric field’s interactions with the charged particles, starting from the first electrode given current and moving to the last. This traveling wave pushes any charged particle off of the surface of the device. Because NASA’s version of the device is to be used for shielding things like camera lenses and solar panels, instead of using copper for the electrodes, KSC made them out of indium titanium oxide (ITO), which is a transparent semiconducting oxide often used in touch screens. They also reduced the distance between electrodes from about a half an inch to a few millimeters for a smoother, more continuous push.
Dust particles do not actually have to be charged to respond to the EDS. There are three classes of particles that will respond to an AC electric field. The first of these is charged particles as mentioned earlier. Charged particles are removed by a force, F = qE, whose magnitude, is determined by the magnitudes of both the charge on the particle and electric field generated by the EDS. The second class consists of large neutral particles with equal positive and negative surface charge. When these particles are exposed to the EDS’ electric field they acquire an induced dipole moment. If the field is non-uniform across the length of the dipole, there will be a net force on the particle called a dielectrophoretic force. The final class of particle are polar particles. These particles have an intrinsic dipole and thus experience the dielectrophoretic force described above.
EDS technology has the potential to make long-term habitation of the moon practical – from smoothly running machines, to efficient solar energy, to safe working environments, to effective communication networks, the EDS lays the foundation for going to the moon and beyond!
Read More: Electrodynamic Dust Shield – Testing
The Exotic and Troubling Properties of Lunar Dust
Lunar Atmosphere and Dust Environment Explorer
Lunar Dust Buster
Dr. Carlos Calle, Lead Scientist, Electrostatics and Surface Physics Lab, Kennedy Space Center, FL
Dust Particle Removal by Electrostatic and Dielectrophoretic Forces with App to NASA Exploration Missions