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In high speed AFMs the vertical axis of the sample positioning stage requires high bandwidth feedback control. In these systems the dynamics of the piezoelectric actuator, its support structure and load play a dominant role in the design of the feedback loop. System performance can be increased by avoiding the excitation of resonant modes of the piezoelectric actuator by modal actuation. In this approach, the piezoelectric actuator is modified to render modes close to the controller bandwidth uncontrollable. Due to its static hardware implementation robustness issues may emerge due to varying loads used for AFM imaging. This paper focusses on performance robustness of modal filters due to load variation.

High control performance is essential in many precision positioning applications, such as control of the vertical sample position in a atomic-force microscope (AFM). This paper investigates the impact of load flexibility on piezoelectrically actuated positioning systems in terms of control performance. The modeling method used combines modal analysis with simple transfer function manipulations, and shows, how the load dynamics may influence the control performance. The analysis is experimentally verified on a commercial AFM system.

In this work we present the fabrication and characterization of high aspect ratio silicon plate springs. The springs are fabricated using a combination of two technologies: high precision dual side wafer stepper alignment and deep reactive ion etching. Several process issues are discussed.and the optimum masking layer configuration to realize these structures is defined. Particularly the DRIE process characteristics that affect the manufacturing accuracy are studied as they form the limiting factor in accurate dual side bulk micromachining of these very high aspect ratio structures.

In this paper, the design and realization of a magnetically levitated high speed spindle for micro machining is presented. This spindle is built to investigate various micro machining processes. The main application is milling with extremely small diameter tools. The micro milling tools have a diameter in the range of 0.1 mm. To improve the milling accuracy extremely high rotational speeds are required. The spindle presented in this research is built to reach speeds over 200,000 rpm. The spindle is equipped with two radial bearings, one axial bearing and a permanent magnet synchronous motor. The radial bearings consist of permanent magnet biased homopolar active magnetic bearings. The axial bearing consists of reluctance type actuators in a differential driving mode. The motor is a commercially available permanent magnet motor, able to reach speeds over 250,000 rpm. This spindle is part of a micro factory, which is built in this research program. The first test results are presented.

The deposition of three wires on the surface of a microcantilever enables both electrothermal and electromagnetic actuation of bending and torsional displacements. Four bending and four torsion modes of a 2700mum times 500mum times 30mum beam were excited electro-magnetically, and two bending and one torsion resonance were excited electrothermally

The design and development of advanced and intelligent systems requires contributions from different technical disciplines. When the required cooperation is successfully achieved a whole range of competitive business options is created. Unfortunately such cooperation is not easily obtained. During the past 15 years the Philips Centre for Industrial Technology developed a strong mechatronics community. For this development the law of cooperation proved to be very suitable to guide the process. The basic aspects of this "law" are presented in combination with some of the technical results obtained during our development.