Towards Electrostatic Levitation of Rotating Machines

Contact-less suspension of macro-scale objects has traditionally been reserved almost exclusively for magnetic systems containing copper, steel laminations, and permanent magnets. Electrostatic systems, on the other hand, have been left out primarily due to their much lower force density in atmosphere. However, the ability to levitate non-ferromagnetic materials, and recent developments in high-torque density electrostatic motors may allow for practical electrostatic suspensions at meaningful scales. To transport electrostatic forces out of the MEMs scale and potentially into the power domain, this paper proposes a unique electrostatic bearing for vacuum condition. Basic operating principles, force analysis, linear system model, and control strategy are presented, along with the structure of an experimental levitator.