A New Hybrid Micromachined Contactless Suspension With Linear and Angular Positioning and Adjustable Dynamics

In this letter, we present a new hybrid micromachined contactless suspension based on combining electromagnetic inductive and electrostatic actuation. In addition, the stiffness components are dynamically adjusted during the operation phase using a series of electrodes integrated in the contactless suspension structure. We experimentally demonstrate vertical linear positioning of a disk-shaped proof mass in a range from 30 to 200 μm, controlled tilting about two orthogonal axes in the horizontal plane ranges from ±1° to ±4°, as well as controlled oscillation about the vertical axis with an angular displacement of 37° at a frequency of 1.5 Hz. In order to demonstrate dynamical adjustment of the stiffness, we experimentally show that the angular component of stiffness is increased by a factor of two at a levitation height of 100 μm. Therefore, the suspension dynamics can be changed and adapted to particular applications or to variations in operational environments. Moreover, we demonstrate that this device can operate as a bistable micro-actuator.