Positioning Stage

Integrated 6-DoF Lorentz Actuator with Gravity Compensation for Vibration Isolation in In-Line Surface Metrology (Thesis)

Design and realization of a 6-DoF actuator system that can be mounted at the tip of a robot arm and can align a precision measurement instrument to its target to perform surface metrology in an industrial environment. The industrial applications are the AFM and white light interferometer measurement of the surfaces of wafers, solar cells and moulds for plastics.

Mechatronic Design of an Electromagnetically Levitated Linear Positioning System using Novel Multi-DoF Actuators

 The development of contactless electromagnetically levitated positioning systems is stimulated by the demand for vacuum compatible production machines. These vacuum compatible machines are used e.g. in the development of faster semiconductor chips and optical discs with larger data capacity. A novel vacuum compatible actuator is the IU-module. The IU-module allows wireless actuation in multiple degrees of freedom. The suspension force of this actuator is generated by permanent magnets allowing the force to be created with low power dissipation. In vacuum environments, low power dissipation is often a requirement due to the lack of convective cooling. In this research, the potential of this novel Multi-DoF actuator is studied by integrating it into nanometre resolution contactless linear position positioning system, the Slider. This Slider has to fulfill the specifications of a linear positioning system used in a modern optical disc mastering production machine. In its most critical direction, the developed Slider using the IU-modules realized a position stability of 0.12 nm (standard deviation) with a control strategy acting on the rigid body coordinates. When additional actuation capabilities of the IU-module were used, the excitation of flexible modes in the Slider could be reduced. This allowed the positioning performance of the Slider to be improved to 58 pm (standard deviation). The challenges addressed in the research are the electromagnetic design of the actuator itself, as well as the integral mechatronic design and control of the linear positioning system.