The contactless wafer handling system proposed by He et al. (2024), relies on continuous high-pressure and vacuum flows, leading to energy inefficiencies and limited scalability due to the absence of localized flow control. The research problem addressed in this thesis is how to passively control these flows based solely on wafer presence, without using active sensors or external control systems. To solve this, a passive valve concept was developed, using bistable rubber domes that actuate in response to environmental pressure changes. A design methodology was applied to create and select suitable concepts, followed by detailed modelling of the dome using FEM simulations in COMSOL, which accounted for geometric imperfections and material properties validated through experiments. Prototypes of the high-pressure system were fabricated and tested to assess valve performance. Key findings show that the high-pressure valve design passively reduced airflow by up to 16% when no wafer was present, with performance highly dependent on dome thickness and inlet pressure. The vacuum valve design, however, failed due to excessive membrane deformation and reversed logic. It is concluded that passive high pressure flow control via pressure-responsive domes is feasible and scalable with proper dome design, while vacuum control requires a revised concept. The validated simulation models and developed manufacturing method offer a solid foundation for future iterations aimed at improving efficiency in wafer handling systems.

Contactless handling systems used to accurately position and move substrates in the order of microns can be mechanically driven by actuators. However, these actuators require high actuation forces of up to 140 N due to the high internal stiffness of the contactless handling systems, which can be modeled as stator-mover systems (SMS’s) with a mover capable of moving up to 3 degrees of freedom (DoF). This MSc thesis report shows the development and realisation of a passive stiffness compensation design for a uniform SMS in translational 1 DoF, using only small displacements in the sub micron level. A uniform SMS was created with a mover that was able to displace in the same range of motion as the largest possible displacement of the investigated contactless handling systems: between -65 µm and 65 µm. After classification on stiffness compensation techniques, a concept was developed based on magnetic circuits using C-shaped yokes and air gaps between the yokes and mover. It was found that the the magnetic circuit concept was able to deliver high forces to introduce a negative stiffness and a magnetic force of 74.84 N at maximum displacement was obtained analytically for a 1 DoF translation. A final design was made using an optimisation on the C-shaped yoke, kinetostatic modeling on the SMS and computations on analytical and numerical fields, which together showed promising stiffness compensating behaviour for the SMS design. A 1 DoF SMS demonstrator was developed and manufactured which contained sheet flexures that ensured the translational motion in x-direction and the ability of an adaptable flexure length to adapt the internal stiffness and adaptable air gap length to adapt the magnetic force. The 1 DoF SMS was validated experimentally to show the internal stiffness and stiffness compensation of the SMS. The stiffnesses were measured using a vibration test to find the eigenfrequencies of the system and a static load test to determine the force-displacement relationship. Stiffness compensations were observed for all investigated combinations of
flexure length and air gap length. A maximum passive compensation of 56.7% was obtained in the 1 DoF SMS, which turned out to have smaller internal stiffnesses than the contactless handling system. Nevertheless, the developed stiffness compensation design shows its potential for a next iteration in which an implementation in contactless handling systems could be possible.

The high-tech industry intends to develop many smaller and thinner products, especially in silicon microchips and solar panel manufacturing processes, to enhance the technologies of the world. In these production processes, fabrications are carried out on increasingly thin substrates to create more microchips or enhance the efficiency of solar cells. Current transport methods within these fabrication machines can degrade and break the ever-thinning substrates, especially those less than 200 𝜇𝑚, which are at risk for continuous damage during manufacturing. One solution to this transport issue is a contactless actuation system using the basis of air-bearing physics. The Flowerbed (a deformable surface air actuator) designed by Vuong is proposed as a solution to this issue. Since the Flowerbed is non-operational, a test bench or equivalent system is desired to be created for control law testing for future Flowerbed-type contactless actuation systems. The development of a model for an equivalent system to the Flowerbed could be adapted and used for deformable surface air actuators or similar. The Flowerbed system is studied, and this research determines that the Flowerbed system can be effectively decomposed into two subsystems: the structural base of the Flowerbed with its actuators and a wafer floating on a thin air film. This is done due to the classification of the thin air film as a constant gain. The two subsystems, the Flowerbed Equivalent and Wafer Equivalent subsystems are combined to create a Flowerbed Equivalent system. The ultimate goal is to classify the Flowerbed Equivalent system as a test bench for the Flowerbed and future deformable surface air actuators. Key objectives for the Flowerbed Equivalent system include achieving functional and performance equivalence between the Equivalent system and the Flowerbed to accurately validate potential control strategies. This thesis aims to design, model, and validate a Flowerbed Equivalent system capable of replicating the dynamics and responses of the original Flowerbed. It includes a detailed exploration of design methodologies, manufacturing processes, and experimental validation through system identification techniques. An equivalent system is designed and theoretically modeled, with the manufacturing process completed for the Wafer Equivalent. Subsequent testing of the Wafer Equivalent reveals that while the initial results are not entirely satisfactory, they demonstrate promising trends. These trends suggest that with further refinement, the Wafer Equivalent can accurately model a wafer floating on air, and by extension, the wafer in the Flowerbed system. The findings underline the potential of the Flowerbed Equivalent and Wafer Equivalent as foundational models, future research is needed to further the physical model of the equivalent system before using it in full operation. This work contributes to the validation of complex system modeling and highlights the importance of iterative design and testing.