Six-axis nanopositioning device with precision magnetic levitation technology

In this paper, we present the design, control, and testing of a 6 degrees-of-freedom magnetically-levitated system with nanometer-precision positioning capability and several-hundred-micrometer travel range. This system levitates a triangular single-moving-part platen, and produces the six-axis motion with six single-axis linear actuators. One of the prominent advantages of this magnetic levitation (maglev) system is that there is no physical contact between the moving part and the stator, which eliminates friction, wear, backlash, and hysteresis. As compared to other traditional devices, the present system is very compact with the minimum number of actuators for six-axis motion generation. The maglev device presented herein shows the position resolution better than 5 nm with 2-nm rms position noise, and is capable of a velocity of 0.5 m/s and an acceleration of 30 m/s². The nominal power consumption is only 15 mW by each horizontal actuator, and 320 mW by each vertical actuator. The actuators are sized to be able to orient and position a maximum payload of 1 kg. The key application of this maglev device is the manipulation at nanoscale for microassemblies and manufacture of their parts. Other potential applications are stereolithography, vibration-free delicate instrumentation, and microscale rapid prototyping.