Active Mechanical Metamaterial for Tunable Vibration Isolation

Materials and material structures with highly specialised and unique mechanical properties are sought after in order to gain the most performance from a system. Materials generally have fixed mechanical properties and are unable to adapt in the case of new or unforeseen situations. Active mechanical metamaterials are able to alter the...

Design of a compliant locally resonant metamaterial unit cell for low-frequency vibration attenuation

Vibrations have been studied in various engineering fields due to their detrimental and even destructive effects on structures. Suppressing low-frequency vibrations has been a research challenge for decades and is mostly achieved by implementing active vibration control techniques. In the last two decades, the emergence of locally resonant...

Design of a Nonlinear Stiffness Unit Cell Aided Magnetic Gravity Compensator

A novel nonlinear stiffness unit cell aided magnetic gravity compensator is proposed for the purpose of isolating low-frequency vibrations. A negative stiffness magnet setup is combined with a compliant unit cell with tailored nonlinear force-displacement characteristics. This combination offers a large range of motion featuring low stiffness, a...

Reset based Skyhook damping: A nonlinear control method for improved transient response.

As the age of industry 4.0 evolves expeditiously, the demand for improved performance in the high-tech industry is rapidly increasing. Industries such as the semiconductor, optical, and metrology have a higher standard in regards of precision to enhance throughput rates and reduce production times between its various stages. The complex machines...

In-Flight Jet Engine Thrust Prediction by Measuring the Engine Vibration Isolators Deformation

The design, build and verification of the Forcesix measurement setup: capable of observing low-level flow-induced vibration forces in 6-DOF

The goal of this study is to develop a measurement setup that can accommodate the water-cooled modules present in the innovative e-beam lithography tool developed by Mapper Lithography and to perform flow verfication measurements on them. The overall objective is to verify the stage-stability requirements set for the Matrix-machine with regards...

Design of an athermal and vibration-isolated Laser-Induced Breakdown Spectroscopy (LIBS) instrument

Industry-wide there is an interest in chemical composition sensing of materials, which requires no sample preparation and can be implemented in real-time. Laser-Induced Breakdown Spectroscopy, or LIBS, is a measurement tool able to achieve this by exciting material, creating an analytical plasma followed by observing its atomic emission of light...

Origami for tunable vibration isolation

It is relevant for various applications to seek a material that could be used for the active control of wave propagation. In this study, we explore tunablemetamaterials based on foldable origami sheets where the size of the bandgap can be tuned by the rigid folding along predefined crease lines. A combination of out-of-plane components and a...

The Design and Experimental Validation of a Permanent Magnet Long-Stroke Gravity Compensator

The ever increasing demand for better and cheaper electronic devices, sensors, optical components, etc. fuels innovation in nanometer precision positioning machines. However, the overall architecture of these machines has not changed much over the past years. A huge improvement in the architecture is currently impossible due to a crucial element...

Fundamentals of low-transmissibility aerostatic pads

Air bearings are known for their low friction losses, constant viscosity and cleanliness, making them favourable in numerous high-tech applications. The relatively low aerostatic bearing stiffness is the major topic in state-of-the-art research and some recently proposed concepts are able to create infinite stiffness. This results in a strong...

An innovative concept for airpot based passive vibration isolation

A new concept was developed to improve current airpot designs for vibration isolation solutions. The concept is based on an additional piston, or add-on, with certain characteristics, that is to be incorporated into an existing airpot-design. The effect of this add-on will passively improve the vibration isolation performance of the airpot. This...

Control for a Cryo Vibration Isolation Platform: Active vibration isolation in 3 degrees of freedom

Experiments in a closed-cycle cryostat suffer from vibrations caused by its pulse tube. To reduce this disturbance, a vibration isolator needs to be placed inside the cryostat. Since mechanical dampers do not work in a cryogenic environment, it requires active damping. This thesis is about the design of a controller for such an active vibration...

Design and experimental validation of low stiffness aerostatic thrust bearings

Linear aerostatic bearings are frequently used in high precision stages for their advantageous bearing properties, with low friction and absence of stick-slip being most notable. To improve relatively low out-of-plane stiffness of air bearings, pre-loading is applied. A common method of pre-loading is by utilizing vacuum, where a constant vacuum...

Development of a Quick Performance Assessment Method for Active Vibration Isolation Systems: Focusing on Photo-lithography Applications

The performance of high precision applications highly depend on the ability to reject mechanical disturbances. Extreme accuracies can only be achieved if the object can be isolated from its environment. Vibration isolation is the process of isolating an object from the source of vibration. In active vibration isolation, an entire instrument of...

Vibration Isolation: On the Determination of Direct Disturbance Forces

Design of a zero stiffness six degrees of freedom compliant precision stage

This paper presents the first zero stiffness six degrees of freedom (DoF) compliant precision stage. To deal with problems like backlash, friction and lubrication for performing ultra-precise positioning in a vacuum environment, a novel compliant structure is proposed. All six degrees of freedom are statically balanced (i.e. near zero stiffness)...

Attenuating vibrations with negative stiffness

Many high-tech equipment demands a vibration free environment and can only operate at vibration levels much lower than typical ground vibrations. This high level of vibration isolation is difficult to achieve with conventional suspension solutions, especially in the range of low frequencies in the order of 1 Hz. The goal of the Kolibri project...