Experimental study of electric suspension for microbearings

Electric suspension bearings with open-loop stability have been proposed as a solution to the problem of surface contact friction resulting from the instability of rotors in micromotors. The proposed electric suspension is an open-loop stable system, which does not require the use of feedback sensors and controllers. A proof of concept experiment of the electric suspension is reported in this work. The experiment consists of levitating and holding a small flat plate in a stable equilibrium under a stator using the electric suspension design. The open-loop stability of the electric suspension is confirmed by photographing the gap between the suspended plate and the stator seen through a microscope. In addition, a gap measurement scheme based on a reflective sensor technique is implemented as a second means to verify stable levitation. The electric suspension is greatly compatible with small scale devices and systems and can be utilized to develop frictionless microactuators