The transmission of pump induced pressure disturbances to nano-precision instrumentation

High-tech systems are subjected to strict temperature requirements. Therefore temperature control using cooling water is vital for thermal stability. Unfortunately, components like pumps and fluid couplings generate flow disturbances, resulting in mechanical vibrations that influence the performance of the system. This research focusses on the...

Mechanical amplification for sensitivity enhancement of a FBG-based sensor

High-tech machines are being improved by extend- ing product quality inspections through implementing better sensors. The resolution of an integrated optical sensor can be optimized through mechanical amplification. In this work mechanical sensitivity enhancement of a Fiber Bragg Grating based sensor is realized, through optimizing output...

Passive film thickness control in hydrodynamic lubrication on non-flat surfaces

Nanoimprinting is a manufacturing method to replicate micro- and nanotextures on large-area substrates with ultraviolet-curable resins. Significant potential of large-area nanopatterning lies in its capacity to greatly enhance the performance of an abundance of devices and foster the creation of cutting-edge products. However, current large-area...

Damping Analysis of Reset Control Systems: an Analytical Approach

The high-tech industry continuously pushes the boundaries of controller performance to achieve faster and more precise machines. Currently, linear control is the standard in the industry. These controllers suffer from the waterbed effect and Bode's phase/gain relation, which impose inherent limitations on the precision and robustness of the...

Measuring Sensing Characteristics of Bending Electroactive Polymer Transducers

Electroactive polymers (EAPs) are smart materials that have electromechanical and mechanoelectrical transduction properties. They are flexible, lightweight, easy to shape and cheap to produce. These properties allow EAPs to be used as actuators or sensors in applications such as soft robotics, metamaterial structures, or other future...

Planar approach for designing and fabricating active metamaterials

Shape changing active metamaterial could form the structural backbone of an object as well as deliver the actuation. The integration of these two functions saves design space and allows for creative topologies. The literature study of this thesis investigated smart material actuator solutions that could be used to enable such active...

Distributed Vibration Control for Robotic cantilever beams: Study of optimal control architectures for robotic metamaterials with relative measurements

Vibrations and disturbances are becoming more of a concern as lightweight, flexible structures in high-tech systems are pushed towards faster speeds and higher precision. Active Vibration Control (AVC) methods have been effectively used to attenuate vibrations and increase the bandwidth of these systems. With the miniaturisation of electronics,...

Active Unit-Cell Structures for Vibration Control: Conceptual Design of Hexapod Struts

In this paper, the implementation of an active unit-cell metamaterial used for vibration control is discussed. The active unit-cell metamaterial is designed for implementation in a hexapod strut. As each of the unit-cells can be sensed and actuated, over-sensing and over-actuation are introduced in the system. This can be used to create...

Functional Iterative Learning Control With Full State Feedback Control of a Flexible Link Robot Actuated With a Stepper Motor

Advantages of lightweight design robot links include cost savings and reduced energy consumption. The flexibility introduced by the lightweight design can cause structural vibrations decreasing precision. To mitigate this, an advanced controller is proposed, consisting of Iterative Learning Control combined with Full State Feedback control. To...

A Low-speed, Low-acceleration Controller for Cost-effective Reaction-wheels: Design, Simulation & Implementation

With the requirements for CubeSats increasing, a push towards utilizing high­performance equipment has never been greater. Incorporating these equipment in an environment that is cost­, space­ and power­constrained, is challenging. Simultaneously, high­performance equipment require high pointing­accuracy and low­jitter. This thesis proposes the...

Developing the soft fluidic actuation unit for future heart assist

Heart failure, caused by a weakened heart muscle that is not able to pump enough blood through the entire body, causes many deaths worldwide. The current heart assist devices designed to treat this acute condition cause a myriad of life threatening complications mainly caused by direct contact with the circulatory blood. A new generation of...

Scanning mirror redesign of the EasyScan retinal imaging system

EasyScan is a scanning system, which images the retina. The condition of the retina can help identify various diseases, such as glaucoma, diabetic retinopathy, cataract, macular degeneration and others. It is a commercially successful device that has sold thousands of units worldwide. However, the scanner is facing lifetime issues, as the...

Active metamaterials: unit cells for tunable damping

The concept of metamaterials has been extended from electromagnetics and acoustics to the field of mechanics. Metamaterials do not derive their properties from those of the composite, but from the artificial meso-scale geometry as well as from the unit cell structure. Mechanical metamaterials are constrained in that the mechanical properties are...