Dick Laro Delft University of Technology Precision and Microsystems Engineering Mekelweg 2, 2628 CD, Delft The Netherlands Tel: +31 15 278 3142 E-mail:
[email protected]
Magnetically Levitated Slider with nm-Precision Introduction
Actuator: IU-module
This poster shows the design of a Magnetically Levitated Slider with nm-resolution. The slider is to be used for optical disc mastering. Here a linear slider holds a laser for writing pits on a glass substrate placed on separately rotating platform. The future optical disc mastering machine demands a Slider with a positioning error of 1nm and a stroke of 50 mm.
Capacative sensors
Laser Linear Slider
Laser Interferometer
Slider
Glass Substrate
Lasers
IU-Module
Slider
Rotating Platform
Approach
Force Frame
To actuate the linear slider three IU-modules are used. The IU-module is a modular two degree of freedom magnetic actuator for suspension and propulsion. The uniqueness of this actuator lies in the fact that there are no wires going to the moving body. As a design starting point the low stiffness design concept has been used. In the “low stiffness” design concept the stiffness between the world and the accurate components of the system is minimized. By doing so the system is isolated from floor vibrations.
Propulsion Coils
Measurement Frame
Results The Six degree of freedom linear slider is build and able to fulfill its design specifications. In the propulsion direction the standard deviation of the error is less than 1nm. Cumulative Position error
Suspension Coil Flux Path
Suspension Coils
Permanent Magnets
Suspension Airgap
Slider Bar
PM flux Paths
Propulsion
Frequency [Hz]
Delft Centre for Mechatronics and Microsystems
Delft University of Technology
