ELITE-3 active vibration isolation workstation

This paper describes the development and capabilities of ELITE-3, a product that incorporates piezoelectric actuators to provide ultrastable work surfaces for very high resolution wafer production, metrology, microscopy, and other applications. The electromechanical, electronic, and software/firmware parts of the ELITE-3 active workstation are described, with an emphasis on considerations relating to the piezoelectric transducers. Performance of the system and its relation to the smart materials is discussed. As the floor beneath a vibration-sensitive instrument supported by ELITE-3 moves, piezoelectrics are controlled to minimize the motion of the instrument. A digital signal processor (DSP) determines the appropriate signals to apply to the actuators. A PC-based interface allows reprogramming of control algorithms and resetting of other parameters within the firmware. The modular product allows incorporation of vibration isolator, actuator and sensor modules into original equipment manufacturer (OEM) products. Alternatively, a workstation can be integrated as an integrated standalone system. The paper describes the system architecture, overall approach to vibration isolation, and various system components, and summarizes motivations for key design approaches.