Magnetic Levitation, or MagLev, technology allows frictionless motion with resolution down to the sub-nanometer range as well as the active control of all 6 degrees of freedom, without any mechanical restrictions or connections. MagLev technology is used in various applications, best known from high-speed trains and magnetic bearings, and has great benefits in precision motion control and nanopositioning applications.
The basic principle of magnetic levitation is that like magnetic poles repel each other. To achieve magnetic levitation in its most simple form, two magnets are used; one magnet is placed in the object that needs to be levitated, and the other magnet is placed beneath it.
To make this principle useful for nanopositioning and precision motion control, for example in linear translation stages, the magnets in the base must be electrically controllable coils and it takes more than just a pair to also control lateral motion, vertical motion and pitch, yaw, and roll. A high-resolution position sensing system is also required for feedback to the motion controller. Since no mechanical bearings restrict the motion of the linear stage platform, all six degrees of freedom are available to correct any bearing insufficiencies, with a powerful multi-axis controller.
Applications of maglev nanopositioning systems can be found in semiconductor test and metrology, photonics, optics and high-resolution microscopy to name a few. Advantages are absence of particle generation (cleanroom compatible) zero-wear and zero maintenance, multi-dimensional controllable motion in a compact package and virtually unlimited service life. In contrast to air bearing stages, no supply of compressed air is required.
PI has been investing in research on magnetic levitation for nanopositioning applications and will work with customers to move the technology forward together. A technology demonstrator is available at PI’s Silicon Valley tech center.