This thesis presents the design and implementation of a fully contactless high precision magnetically suspended position stage with large planar stroke. This stage is the first which is suitable for practical application in vacuum. The underlying electromechanical working principles, modelling and analysis, the mechanical and electrical design, real-time control, and the experimental results of a test set-up are presented. The possibility to combine magnetic suspension and propulsion in a single actuator was proven experimentally by a PhD investigation performed by Frank Auer in the years 19901995 at the Laboratory for Micro Engineering at Delft University of Technology. Prototypes showed low cross-coupling of suspension and propulsion, and sensor-limited accuracy. In 1995, this research started as a follow-up, with the goal: improvement of the practical applicability of linear Active Magnetic Bearings (ambs) in the field of Precision Engineering. Therefore, an investigation into the state-of-the-art in ambs was performed, which revealed that, due to the high development costs, ambs can be applied best for either high end applications (e.g. linear motion stages with high precision and throughput) or for high volume consumer products (e.g. bearings for hard disk drives). These applications then profit of the general advantages of ambs, like contactless operation (no wear, no maintenance, possibly application in vacuum, absence of stick-slip), and adjustable bearing characteristics (servo position, variable stiffness and damping, active vibration isolation). Disadvantages that may limit the applicability are the limited dynamic stiffness and bearing force, with its accompanying break-through risk, and the heat development by the coils. While rotational amb actuators are mature, and have become commercially available for several years, major development effort is focused on advanced control, reliability, modularity, and cost reduction there. In contrast, linear amb actuators are still evolving. Compared to their rotational counterparts, linear systems offer only one additional degree-of-freedom, but this leads to much more freedom of the electromechanical actuator design. Since no specific application was predefined for this research, a market investigation was performed. The results were combined into the definition of a target application. When the requirements for such an application were compared to the performance delivered by the stage that was developed by Auer, it turned out that the range of the planar stroke, the positioning accuracy, the propulsion force, and the acceleration all needed to be improved, before practical application could be considered. Moreover, for application in vacuum, the development of heat should be minimized, and the power dissipation on the suspended object needs to be negligible. This can only be accomplished by a thorough re-design or a completely new principle. Based on an investigation of the principles of electromechanics, and the status and applications of electromechanical actuators in general, a number of desirable capabilities was defined at the beginning of the work described. Six possibilities are identified that appear promising for improvement. 1. Developing an integrated Lorentz drive with reluctance bearing 2. Exploiting the ongoing improvement of rare earth permanent magnets for applying them for biasing 3. Applying crossing flux-guidance bars introducing a lateral freedom of motion 4. Applying a wireless propulsion (moving iron) removing both the heat of the coils of the rotor as well as avoiding the flying umbilical wires 5. Applying high permeability coil winding material, improving the number of ampere-turns in the air gap Some of these possibilities are new, while others are known from the state-of-the-art but are new in the combined or integrated application presented. For all of them, experimental demonstrators were built to investigate the feasibility and effectiveness. The first four possibilities are combined into a novel integrated planar active magnetic motor-bearing concept, the pamb, for which a patent application was granted. The basic pamb configuration can control two to four degrees-of-freedom. Numerous, differently shaped actuators can be derived from it, that all allow for a long, principally unlimited, planar or angular stroke. The novelty lies therein that the advantages of a list of magnetic bearing and motor aspects are combined into an indivisible, integrated solution. The novel configuration integrates: * energy efficient variable reluctance type suspension, * permanent magnet biasing for fast acceleration and hence high position stability, of both bearing and motor, * extended, crossing flux guidance bars that enable motion over a long stroke, while freedom of motion is allowed for long orthogonal linear or angular strokes, * saturation of parts of the yoke, which simplifies dimensioning and fine-tuning of the permanent magnets, and ensures an optimal bias flux level, all over the long stroke, * direct Lorentz propulsion without any wires on the flat iron rotor bars, but instead with wire on the fixed stator yoke, where conduction can cool the windings, which makes the stage applicable in vacuum, * simple shaped yoke parts that are easy to produce, and * a high evolvability, meaning that the system can be scaled up to even larger strokes without changing the maximum obtainable acceleration. Based on this configuration concept, a 6dof experimental set-up was built that demonstrated the practical feasibility. The set-up, called the pamb, shows a robust behavior of the suspension, over a full planar stroke that covers 130 mm 130 mm. The novel moving iron propulsion, with magnets and coils on the stator only, proved to work equally well as the common engineering solution with coils on the moving part. Thus, all advantages of the system by Auer are maintained, while the planar stroke has been enlarged 16 times, the dissipation during suspension is decreased from 84 W to 0.8 mW, and the heat generation and flying wires associated with the propulsion force are taken away from the rotor. Currently, a propulsion of 0.2 g can be reached at a total of 200 W dissipation in four propulsion coils on the stator. It should be noted that the experimental system was not optimized for a high acceleration. When, as a follow up towards practical application, a prototype is to be built, acceleration can be improved by a factor five at least through the addition of windings. In addition, by switching of coil segments, the dissipation can be decreased a factor five. Since the acceleration that can be obtained with the homopolar Lorentz force within the pamb set-up is limited, it is recommended that, to further improve the acceleration in propulsion direction, salient poles are applied instead of the flat wound propulsion coils. Although, compared to the current pamb, both motor types are stronger, they have the following drawbacks. Firstly, cogging forces are introduced, secondly costs increase, and thirdly start-up of the bearings is complicated. The advantage remains that the maximum bias flux which can be controlled by the magnetic bearings is utilized still; even employed for both functions. Based on the outcome of the experiments, it is concluded that merging two basic pamb elements leads to non-linear couplingboth mechanic as well as magnetic that complicates improvement of the sub-micron position stability as achieved with the experimental set-up realized. Therefore, an alternative actuator layout is suggested that can control four degrees-of-freedom at max, which may serve as a building block for contactless positioning systems. The work presented demonstrates the large potential in electromechanical actuator design, to achieve compact and low cost solutions for integrated motor-bearings. Since the pamb actuator concept meets the requirements set by a number of practical applications, it is recommended to start a technological research project with the aim to develop an application dedicated prototype. For this, a list of suggestions for improvement is given, of which many are combined into the alternative planar motor-bearing design mentioned above. Finally, several suggestions are given to continue this research project by a dedicated research of either the force-current relation under the influence of yoke saturation and stray flux, or of a zero intrinsic stiffness motor-bearing actuator suitable for long linear or planar stroke.