In the semiconductor and photovoltaic industries, contactless positioning systems are increasingly employed to handle ultra-thin wafers, minimizing the risk of mechanical damage. A suitable and integrated sensor system would make this handling method more attractive in future applications. This Msc. thesis explores a novel concept in planar position measurement for flat, reflective objects using fiber optic sensors distributed across a measurement plane. This sensor configuration creates light profiles via transmitting fibers and utilizes the reflected light detected by receiving fibers to localize the object's position.
A Gaussian-distributed intensity pattern is first applied to the light profiles to validate this concept, establishing the theoretical relationship between brightness and planar positions. A prototype with a single set of fibers is then constructed to verify the proposed brightness model and determine the optimal, sparsest fiber spacing that maintains adequate resolution. In the next phase, algorithms are developed using simulated sensor arrays to calculate planar degrees of freedom based on the actual positions and brightness values from receiving fibers near the object's boundary. These algorithms are then implemented in a fabricated sensor array prototype, forming a complete distributed fiber optic sensor system.
The sensor's performance is evaluated using samples with varying center positions and orientations, resulting in an average error of less than 1 mm in the in-plane directions. In conclusion, the proposed sensor configuration limits planar position errors to sub-millimeter accuracy. The measurement range is significantly extended, and the sensor element no longer needs to be attached to the measured object. As a result, this system offers promising potential for contactless planar positioning of thin, fragile products with specular surfaces.

Over the past decades the increased use of Micro Aerial Vehicles (MAV's) in a large range of fields and applications has lead to a call for more energy efficient MAV's. Here Flapping Wing Micro Aerial Vehicles (FWMAV's) offer the possible solution since it was shown that animals such as colibris and insects have very energy efficient flight mechanics. The drawback of these currently developed FWMAV's is that they have limited lift generation. This limits the energy that can be carried in the form of batteries. This posses limits on the amount of energy that can be spent on both control and sensing. One solution is to use insect inspired optic flow sensors and a simplistic control method to directly control the velocity, instead of using the standard acceleration and GPS measurements. The insect inspired optic flow sensors allow for the measuring of velocity over distance relation. This method allows for a controller to take advantage of the sensor behaviour in order to increase responsiveness close to walls or at high velocities without need for complex control methods. With this goal in mind, two different sensor control variations were developed and tested in a simulation environment. Here the effect of different parameters and conditions were studied and analysed in order to evaluate the effectiveness and potential of these controllers and the general control approach. Analysis show that the behaviour of both controller respond slightly differently on the change in the initial position for a given initial velocity. The implementation of a more realistic sensor did result in different behaviours for certain initial conditions.

The ever-growing demand for high-performance materials and more functional 3D printing has raised tremendous interest in advancing Multi-Material Additive Manufacturing (MMAM). Developing C-FRTP 3D printing through FDM Technology opens new scalable FRP solutions. These components possess exceptional properties such as specific strength, recyclability, impact/chemical resistance, and geometrical complexity. Researchers have successfully exploited FDM technology to print C-FRTP composites but lack high interface bonding between the reinforcing fibers and thermoplastic polymer matrix. Moreover, C-FRTP is limited to weak frictional forces and mechanical interlocking. Besides, porosities are observed at the interface, which results in overall mechanical weakness.

Various Meso-level C-FRTP 3D printing methods and print heads have been developed and standardized, but more knowledge is needed of essential 'In-Nozzle' C-FRTP impregnation dynamics. During In-Nozzle impregnation, solid-dry fiber and molten Thermoplastic polymer matrix bond inside the print head before extrusion. This master thesis explores the challenges and potential solutions by conceptualizing a functional ’In-Nozzle’ impregnation extruder capable of extruding proper C-FRTP composites using FDM printing.

Initially, a theoretical framework is presented on melt impregnation dynamics and Interface adhesion, followed by experiments as validation. Based on the melt impregnation analysis observations, a limited permeability of Thermoplastic polymer melt is observed. These are primarily from the high viscosity of the thermoplastic materials (PLA) and the dense fibers. Applying an overflow of melt with extensive external pressure achieves a smoother and faster melt flow around the interface. Tensile strength experiments underscored the dependency on the exposure time and encapsulation of fibers by matrix and showed an increase in IFSS compared to the neat thermoplastic polymer. Further research is recommended to augment contact surfaces between fibers and the matrix. This research highlights the current challenges and lays the foundation for future advancements in C-FRTP 3D printing through in-nozzle impregnation, offering insights into improving material compatibility, impregnation quality, and interfacial bonding.

A prototype lunar rover is in development by students of the TU Delft since 2017. It is a nanorover based on the terrestrial ZeBRo design, now named the Lunar Zebro. The Lunar Zebro is a prototype design as a proof of concept for nanorover capabilities. With a chassis of 200 by 140 by 60 millimeters, fitting on a sheet of A5 paper, the Lunar Zebro is intended to be the smallest and lightest autonomous rover on the Moon to date. The objective is to traverse a distance of 200 meters during a lunar day, surviving the harsh environment and strong solar radiation. Due to the limited time budget there is little refinement in the structural design. The resulting functional but heavy design leaves many opportunities for optimization.
While there are many examples of successful planetary rover missions, little is published concerning the design of the structures. This report contains further analysis of the design of satellite structures. The various structure types and design requirements highlight the importance of thermal transport and resistance to mechanical launch loads. Compared to the deployed planetary rovers, the Lunar Zebro is unique in many ways. The small size facilitates production of the current monolithic chassis which is ideal in its thermal conduction and environmental sealing properties. However with a constant plate thickness and no reinforcing substructure, the structure is not an efficient loadbearing design. Due to the many requirements and unique mission profile of the Lunar Zebro, there is no clear method by which to optimise the structure.
To better understand the current structure and reduce the mass, a case study is performed with Finite Element Methods. After validating a modelling approach for thin plate reinforcement, a simplified chassis structure is generated. Maintaining the essential configuration of the chassis and connected components, the response to the static launch load of 10G is analysed. Several methods for rib placement design are tested while reducing the plate thickness. Buckling behaviour and CNC production limitations are accounted for in this approach. To minimally affect the other design requirements, the stiffness of the structure is maintained. While the placement of ribs is sensitive to the vicinity of connected components, equally stiff designs can be obtained with reinforcement grids. Reducing the plate thickness by 66.6%, a mass reduction in the order of 50% can be achieved without sacrificing stiffness. However, local adjustments are required to prevent plastic deformation in high stress areas.
From there the analysis and design of reinforcement grids is investigated further. Grids are often seen in aerospace applications due to the convenient geometries for CNC production, light weight and predicable orthotropic or isotropic behaviour. A smeared stiffness approach is investigated that relates the rib and plate interaction to composite plate theory. Applying this analysis method provides beneficial insight in the parameters and related stiffness behaviour of a grid reinforced plate. By modelling three common grid sections on a hypothetical plate design scenario with varying boundary conditions, the important criteria for the selection and design of a reinforcement grid are provided.

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 displacement and force (strain) with limited input force and displacement. A compliant mechanical force amplifier is designed with key parameters, through which the amplification of the structure and its stiffness versus efficiency are adjustable. Input compression is converted to output tension and its two flexible hinges are loaded axially in tension. The simple one DOF lever mechanism can be used as a building block for compound mechanisms. Through a Matlab model based on beam theory a parametric analysis is performed. A functional load test is performed to experimentally verify the design function. A finite element analysis in COMSOL is used to validate optimal designs and compared to the model and experiment. Through topology optimization a rhombus design is generated, which is compared with the lever designs. The initial strain of a 2 mm steel rod at 1 N input force is 0.38 με. By integrating the in-line amplifier/transducer that gets compressed by 41.9 μm and amplifies the force by a factor 1.64 with an efficiency η of 65.6 %, the output strain is improved to 2 mε, by a factor of 5300. The number of resolution steps with an interrogator resolution of 1 pm/bit and a fiber transduction of 1.21 pm/με is ε · T /R = 2435. The force per resolution step is 0.41 mN . An integrated FBG-based sensor combined with the mechani- cal amplifier/transducer is a viable option to measure input force with a high resolution. The next step is to realise implementation with the sensor and a 1:1 scale prototype fabricated with milling and wire-EDM.

This research work presents the observations of the updated quasi-steady aerodynamic model of the Atalanta project, a flapping wing Micro Air Vehicle (MAV) project, for additional velocity conditions. The main focus of this research work is to update the existing quasi-steady model of Q.Wang developed for hovering conditions since its performance under additional velocity conditions remains unexplored. This work thus examines the influence of the additional velocities on the computed aerodynamic loads such as lift, drag, and also the influence on the passive pitching motion.
To incorporate the additional velocity into the quasi-steady model, the resultant translational velocity is computed by the vector addition of the kinematic velocity of the wing and the additional velocity. This is done by transforming the additional velocity in the inertial frame of reference to the co-rotating frame of reference, followed by the proper vector addition of the translational velocity components to compute the resultant translational velocity to be used in the aerodynamic load calculations.
Observations reveal that the generated aerodynamic lift and drag, and the passive pitching motion vary depending on the orientation and the magnitude of the additional velocity with respect to the kinematic motion of the wing, and that the significance of influence of the additional velocity magnitude depends on the flapping frequency and the elastic hinge stiffness. The results observed are analyzed to understand the influence of various additional velocity conditions on the computed aerodynamic loads and the passive pitching motion.
The updated model provides valuable insights into the behaviour of lift, drag, and passive pitching motion under various additional velocity conditions which can be used as a basis for approaching the solution of forward flight. These observations contribute to a better understanding of the aerodynamic quasi-steady model of the Atalanta project and pave the way for future research and experimental validation of the model.

This thesis describes the process of designing a visual effect to replace the needle indicator of a rattrapante complication. The mechanisms of the chronograph and rattrapante are explained as well as the importance of aesthetics in the luxury watchmaking industry. After establishing a method to determine a feasible design, the criteria that need to be fulfilled for the final design are quantified. Extra attention is given to: the minimum part size with respect to human visibility; assessing the aesthetic value of different visual effects based on a survey; and quantifying the maximum rotational inertia by means of a friction study. From the aesthetically pleasing ideas from the survey feasible concepts are generated as well as weighted with respect to each other. The best concept is turned into a working mechanism by establishing a production method and calculating stresses in compliant flexures. A torsion hinge that can be produced from a double-BOX-layered silicon wafer is also designed. The actuation by a discrete vertical clutch gripper is designed as well as the extra parts needed for a fully functioning mechanism that fits the design space. As a result, a demonstrator at scale 15:1 is build to show the working mechanisms of the design as well as the visual effect itself. It concludes with a successful mechanism which probably also has relevance in other watches.

The offshore industry is adopting Autonomous Underwater Vehicles (AUVs), to decrease the costs associated with surveying underwater sites. Despite requiring less human supervision, AUVs still depend on costly servicing from a vessel, before and after deployment. Combining an AUV with an Unmanned Surface Vessel (USV), a survey vessel that operates without humans on board, could drastically reduce operational costs. This thesis focuses on the crucial requirement of this combination: the autonomous docking of the AUV to the USV.

Current studies focused on the AUV-USV combination lack effective solutions for docking in rough ocean conditions, while this is key for its operational employability. These studies have explored horizontal docking approaches, while an unexplored alternative is a vertical docking approach from below the USV. This approach may experience reduced influence of waves, as the wave disturbance acting on the AUV and the USV are phase synchronized. The objective of this study is to evaluate the viability of vertically docking an AUV to a USV in rough seas, using the Lobster Scout AUV as a case study for an initial performance evaluation.

This study first identified and scoped the key elements for this initial performance evaluation, which included the waves, the USV, the Lobster Scout, the Docking Station (DS), and vertical docking Guidance Navigation and Control (GNC). Furthermore, the scope was limited to the critical docking stage, where the vehicles are within meters of each other. The study used simulation as the primary method to investigate the thesis objective and a 2-Dimensional (2D) model was developed to simulate the system dynamics, which was fitted and verified using a variety of methods, including analytical calculations, mesh convergence studies, experiments, and visual analysis.

To determine the viability of the vertical docking approach of the USV-AUV combination, a probability distribution-based method was developed. Viability was expressed in terms of the maximum operational sea state and the estimated operational up-time. Since docking success under the presence of waves is described probabilistically, the requirement was set that at least 991 out of a 1000 docks should be successful. Furthermore, Monte Carlo simulations were used to obtain the docking performance over a variety of sea states, navigational settings, and different guidance and control methods.

A target state vertical guidance method using way-points was designed with various Proportional-Integral-Derivative (PID) based controllers to guide the Lobster Scout to the DS. It was also determined whether kinematic prediction or polynomial prediction could improve docking performance and the impact of navigation on docking performance was investigated. It was found that the vertical docking approach shows promise for enabling a reliable AUV-USV combination for the Lobster Scout in medium to rough seas, with a significant wave height of 1.65 m and 3.6 m respectively, resulting in an estimated annual operational up-time of 59 % to 94 % in the North Sea. Furthermore, there is potential to achieve even higher sea states with improved GNC methods.

Overall, this study suggests that the vertical docking approach can lead to a viable AUV-USV combination with improved operational employability compared to current docking studies using horizontal approaches, although the author is of the opinion that both approaches require further investigation.

Drones are becoming an ever increasing part of our lives. From airshows to surveillance systems, their use varies greatly and, as technology improves, this variety will continue to increase. As drones get smaller, new applications arise. For example, drones for monitoring crops or searching for survivors in hard to reach places in disaster areas. One of the main fields of improvement to drone design is energy efficiency. The more energy efficient a drone is, the longer it can fly and the more it can carry. This is the objective of the Atalanta project.
It seeks to develop a drone with a wingspan smaller than 15 cm and an improved energy efficiency over other drones. It does this by two means. Firstly, it uses a bio-inspired flapping wing solution, mimicking the methods used by insects to fly. This carries a greater efficiency over the more ubiquitous rotary wing design.
Secondly, it looks to apply resonance, allowing more energy conservation between wing flaps.
In its current state, the Atalanta project has gathered an expansive amount of theoretical knowledge, but lacks the validation a prototype would provide. This report gathered the knowledge contained within the Atalanta project and supplemented it with new information generated in the last two years. It identified three main challenges to overcome and provided a set of guidelines to overcome them. The challenges are as follows: Firstly, the total design is too heavy for the theoretical lift generated by the wings. Secondly, the wings, in their current form, are too heavy for an actuator to operate at the right frequency. Thirdly, little documentation exists on the design of the resonant element the design has to be built around. If all three of these challenges are addressed, it should be possible to create a flying prototype for the Atalanta project
using an external power source and external control.
To overcome the limits of the generated lift, varying actuators were evaluated. As no actuator was found meeting the projects requirements, a gearbox solution was sought instead. Through the use of a linear frequency divider, the available power from an actuator could be doubled by doubling the operating frequency
of the actuator without changing the flapping frequency of a wing. A linear frequency divider was developed for this purpose. As this element also fulfils the role of the Atalanta body, the third challenge was also addressed through this element by designing it to function as a resonant element, vibrating at the desired frequency. This linear frequency divider was successfully developed, but was unable to be integrated into the prototype within the available time.
To address the weight of the wings, a vacuum forming method was investigated. By applying heat to a film of plastic and pulling it over a mold using a vacuum, a wing of a desired shape can be created. By introducing localised folds in this wing, it can be reinforced and be made stiffer. Although this seemed promising, no suitably light wing was produced using this method, but further research is likely to produce positive results. As only mylar was investigated in this paper, evaluation of other materials could prove productive. Alternatively,
using a combination of vacuum forming and local reinforcements may well create a near rigid wing.
Despite the increase in losses due to the heavier than desired wings, the drone presented in this paper could theoretically fly for short periods of time, as the losses of the flight are compensated for by the energy provided by the used actuator. It was originally predicted that the Atalanta would have a power density requirement of 30 W/kg. Despite the heavier wings and the increase in weight from the components added by the linear frequency divider, the new loss to mass ratio is only 38.4 W/kg. The weight of the prototype has increased as well, however. Despite all this, the actuator is predicted to be able to deliver 1.15 watts of power with the losses being 0.713 watts. As such, with the addition of the linear frequency divider, the prototype can theoretically fly, if integrated properly. Also of note is the lack of optimisation for the linear frequency
divider. As this is the first paper investigating this part, a substantial amount of time was spent evaluating the effectiveness of the part. As such, further investigation in this area could lead to further optimisation or even the inclusion of a second divider, allowing the frequency of the actuator, therefore its power, to be doubled again.

Flying drones have been a well-established field of engineering for many years now. With the wave of bio-inspired design came the idea of flapping wing micro air vehicles (FWMAVs). These drones use flapping wings instead of fixed or rotary wings to generate their lift, giving them the potential for agile movement and application in confined spaces. The Atalanta project is one of the groups trying to create a working and efficient FWMAV. While a lot of progress has been made in optimizing the flying motion, the vehicle so far does not have a control mechanism yet. This master thesis seeks to compare methods to achieve this control and propose a final design for a hinge that will be verified experimentally.
A selection of materials and methods for inducing structural changes is tested using analytical models. After picking the most viable options a numerical model seeks to find which of the remaining materials or methods has the highest effectiveness given a set of volume constraints. The most effective design is adapted into a proposed final design for the Atalanta project. The theoretical finalized design fulfills the constraints and functions using a voltage as low as 15 V. To verify the physical principle behind the design experimentally, a few changes are made to the design to allow the construction of a simplistic measurement setup. After the experimental validation it is concluded that the design in its current form is not effective enough to achieve control in the Atalanta FWMAV, and some suggestions are offered to improve the design in future research.

The Lunar Zebro is a small moon rover that needs an advanced chassis to endure the harsh environment that the moon brings. To arrive at a solution for such a frame or chassis creativity and hard work are necessary. Whereas hard work is a given, creativity is not and it may need a helping hand. Design synthesis methods, of which brainstorming is a basic example, aid engineers and designers with reaching better solutions. Currently, however, which method works best for a given scenario is unknown. The purpose of this research is to determine which synthesis method works best for concept generation, with the focus lying on generating innovative solutions for frame design. A meta-method is created to evaluate the performance of different synthesis methods when applied to design cases. This meta-method consists of executing fifty case-method combinations, built up from pairing ten design synthesis methods with five design cases, which are focused on frame design primarily. The combinations are then evaluated using a self-made rubric. In the end, it became apparent that different methods apply well at different stages of the design process and at different system levels. Some work well to orient, understand the supersystem and therefore have an positive yet indirect influence on the final outcome. Some work well to generate concepts, bring new ideas at system level. Others apply well after a concept is already generated, only being useful to improve subsystems.

Energy harvesters subtract energy from their surroundings and convert this to electrical energy. Even though energy output is generally low, energy harvesters can offer great value by offering the possibility of self-sustaining devices, combined with the developments in low power semiconductors. Many examples can be found of applications that would benefit from energy harvesting. Not for all of these, suitable harvesters have been designed. Research has concluded that lacking performance of vibration energy harvesters (VEH) in the application fields of human wearables and remote sensing is the main hurdle in the widespread implementation. One application within remote sensing is wireless sensor nodes for monitoring the health of buildings and infrastructure, such as bridges.

For the company Kinergizer, a feasibility study has been performed in this research for a new type of VEH for traffic induced bridge vibrations. Challenges lay in the intermittent character of the vibrations, because many VEH are resonant based, combined with low amplitudes and accelerations. In the performed study, a VEH design is presented for these vibrations, a mathematical of the dynamics has been made and a proof-of-concept is build which is tested under repeatable (harmonic and shocks) accelerations and under bridge-like conditions.

With the tested system parameters, the mechanism is able to harvest energy from the repeatable tests, but not from the bridge-like excitations. Further research is needed to determine whether, with suggested alterations, the presented working mechanism might be able to.

Remotely controlled vehicles have gained increased interest and application, like the exploration of inhospitable environments. To this end hexapods with C-shape locomotors are particularly suitable because these vehicles possess both the efficiency of wheels and the climbing capabilities of legged robots. Currently all C-legged hexapods are equipped with the same C-shape tip starting in the center of rotation, yet few to no alternative shapes that could improve the performance have been investigated. The performance is mainly characterized by three measures: traction, climbing and mobility. However, it was also found that no system level performance analysis including constraints exists. In this work a novel method is proposed to describe the system level performance of C-legged hexapods. Using this model, a computer-aided manual optimization of the leg shape is performed, from which it is observed that there is no unique optimal leg shape. The optima depend on the weight factor posed by the designer; but several leg types prove to perform better than the conventional shape. The most prominent trade-off of this hybrid shape is present between climbing and mobility, but this effect can be superseded when the shape is generated conceptually instead of analytically.

Mobile electronics or remote devices like sensors for the Internet of Things (IoT) require energy storage with increasing energy densities, approaching the limits of the widespread lithium batteries. At the same time, lithium batteries are subject to growing criticism about their environmental impact due to their raw materials and their mining methods. Chemical energy seems to be a promising alternative and the development of micro combustion to make use of it is already for almost 30 years the topic of ongoing research. Recent studies show that compliant combustion engines are a good solution to mitigate some problems like leakage and friction and thus, achieve higher efficiencies. However, the most prevalent problem is heat losses through the walls because of the high surface-to-volume ratio in small-scale combustion. In this work, a design concept was proposed that not only insulates the compliant combustion chamber of the actuator for Flapping Wing Micro Air Vehicles (FWMAV) but also uses the waste heat to generate electricity. That was done by attaching Thermoelectric (TE) modules to a support structure and thermally connecting them with porous media to the oscillating combustor wall. The actuator uses the heat and pressure generated by the catalytic reaction of hydrogen peroxide and therewith, only emits steam and oxygen. With the help of a one-dimensional steady-state heat resistance model and a one-dimensional transient heat resistance-capacitance model, an optimum design was found. With that, it is possible to create a temperature difference sufficient enough to enable energy harvesting by TE modules. That was achieved by implementing an exhaust gas recirculation which
transfers heat to the modules and simultaneously serves as a heating blanket for the combustor. A downside of the design is the relatively long time it takes to reach its steady state and especially for FWMAV, the increase in weight.

The use of optical fibres as distributed vision sensor within a contactless handling system is discussed in this study. The three primary light colours and a volume diffuser will be used to detect the edge of an object levitating on an air-bearing table. One building block of a bigger system is used that consists of one receiving fibre in the centre surrounded by three transmitting fibres, with each transmitting one primary light colour. Various experiments were executed to find a range where the object edge can be detected. The transition range for horizontal and vertical movement is found. The backscattering of light within the volume diffuser turned out to be much larger than thought. This backscattering causes a small light intensity range. Also, some disruptions in the emitted light caused no logical transition ranges. A model is made to see what happens to the transition ranges when the disruptions are eliminated. The red transmitting fibre is investigated to see the individual contribution to the light intensity received in the receiving fibre. The transition range got from that measurement is translated into the transition range for the green and blue transmitting fibres. Through interpolating the ranges, a total measurement range is found where the object edge can be detected at whatever angle the object is positioned. A bigger system can be made by connecting more building blocks. The proposal for future research is to investigate the positive or negative effects of connecting multiple building blocks.

Over the past decades Minimally Invasive Surgery (MIS) has become a standard in abdominal surgery. Due to limited dexterity and bad ergonomics the field of MIS is shifting towards Robot-Assisted MIS (RAMIS). Simultaneously, the field is using increasingly small and steerable instruments to reduce invasiveness. Surgeon now work with fragile instruments and tissues and are not able to feel the forces they apply. This can lead to unwanted damage to patient and instrument. In an effort to reduce the risk of accidental damage, this work presents a force sensing strategy that is able to measure tip forces in RAMIS using 3mm shaft actuated tip articulated instruments. The system uses a sensorized trocar fixed to the same frame as the instrument to eliminate interfering forces occurring at the trocar. Bending in the instrument due to the applied force at the tip is measured using Hall effect sensors with a silicone transducer. Prototype testing and validation show the proposed sensing system is both accurate and reusable.

Hexapod robots are becoming increasingly popular for navigating and exploring irregular and inhospitable environments. The Lunar Zebro is such a hexapod robot that has been developed to be the lightest and smallest rover to explore the moon. The purpose of the Lunar Zebro is to navigate the surface of the moon where it will encounter difficult terrains such as regolith (Lunar Soil) and rocks. To date, not much focus has been placed on the design of the Lunar Zebro legs to increase the rover’s trafficability on these terrains. Furthermore, the designs of rover wheels are constantly changing, and new lessons are being learnt from each new mission that the guidelines for designing the wheels and legs of rovers are constantly evolving. Using a Biomimicry design framework, the legs of the Lunar Zebro were redesigned using strategies adopted by animals in nature to improve the trafficability of the legs on granular and rocky terrains. Several concepts were created and narrowed down to four final designs (Hair, Web, Paddle and Claw Legs) that were further developed and manufactured. In addition to this, the original leg design and a flat leg with no grousers were developed for testing.

Several different single-leg tests were performed on the legs to measure their sinkage, thrust, rolling resistance and drawbar pull on regolith and rocky surfaces. The results showed that hair has the potential to reduce sinkage on regolith. However, the results from the single-leg tests on regolith also indicated that there is not much difference in the drawbar pull performance of the different legs no matter what features were included on the bottom of the leg or if the leg had grousers or not. In contrast, the results of the experiments performed on rocky surfaces showed that legs with claw-like grousers performed the best.

From there a hybrid leg was designed using the finding of the single-leg tests and this leg was tested on a basic Lunar Zebro prototype against the original Lunar Zebro leg design to determine if the hybrid improves the trafficability of the rover on both regolith and rocky terrains. These tests included testing the drawbar pull of the rover at 100 % slip and measuring the distance travelled by the rover over five steps. The results showed that on regolith terrain, the design of the leg does not have a big impact on the performance of the rover. However, the results showed that on rocky terrain the rover with hybrid legs travelled roughly 10 % further over five steps and had a drawbar pull roughly 10 % larger than the rover with original legs.

Cochlear implants (CIs) are the most effective solution to treat severe-to-profound hearing loss. These medical devices mimic and replace the function of the damaged structures of the cochlea. To this date, more than 700,000 individuals worldwide have benefited from CIs. However, state-of-the-art CIs do not provide a natural and high-quality sound perception to their recipients, who poorly appreciate music and hardly understand speech in crowded or noisy atmospheres. Furthermore, CIs are expensive and unaffordable for poorer portions of society. The CI electrode array is the component that presents the most margin of improvement as it is still composed of classic materials and is fabricated via a tailored manual manufacturing process that does not maximize the potential of the system. Concretely, commercial CI electrode arrays contain from 12 to 24 individual stimulating channels that cannot optimally substitute the role of the 3000 neural stimulation sites of a normal-functioning cochlea. Moreover, most of the commercial CI electrode arrays cannot fit in the narrow deep areas of the cochlea to completely cover the low-frequency audible spectrum. Hence, to overcome these limitations, novel strategies and materials to optimize CI electrode arrays ought to be investigated. Chapter 1 of this work starts with an introduction to the auditory system and the different types of hearing loss. Chapter 2 goes through the history and research that led to the development of cochlear implants and presents their main components and current limitations. Chapter 3 discusses in detail the state-of-the-art of CI electrode arrays and Chapter 4 reviews novel materials to enhance them. In Chapter 5, PEDOT:PSS is suggested for the development of all-polymeric cochlear implant micro-electrode arrays. Initial experiments provide a proof-of-concept that demonstrates that by patterning PEDOT:PSS layers with conductive and non-conductive areas, it is possible to create electric circuits with superior electrodes and leads that give rise to all-polymeric CI micro-electrode arrays. Future work will be directed towards developing an actual prototype using this strategy. Furthermore, a study of the long-term stability of the material will be necessary.

In this thesis the design possibilities to replace a Lavet-type motor with an electrostatic motor are investigated. At the moment, almost all quartz watches use a Lavet type of motor. Two electrostatic conceptual designs are made by Timex and Accutron. An electrostatic motor for the watch application looks promising due to the more efficient scaling of force compared to magnetic, and since the current design consists of an intricate and, relative to the rest of the movement, bulky coil of wires. Various designs were devised and then analysed. The concepts were selected based on ease of manufacture and potential losses, resulting in the two best designs. In the investigation, various mechanisms for losses in the concepts are calculated, and the concepts are compared to each other. The most promising concepts to replace a Lavet type motor are a ratchet comb design and a top drive. A quartz motor designer can choose different parameter sets to get a high efficiency or a low surface area of the actuator. The ratchet comb and top drive design have approximately the same efficiency or better as the current Lavet motor, and the size is approximated to be between 3−20 mm2 where the Lavet motor uses a surface of around 80 mm2.

Multi­-material 3D inkjet printing has great potential for rapid prototyping and manufacturing of functional mesoscale structures when novel inks are combined into a fully integrated AM-process. This process can be faster and cheaper than conventional methods to produce functional structures. Research is conducted on a large range of potentially inkjet­-printable materials to extend current possibilities with 3D inkjet printing. Material incompatibility together with strict fluid properties limit the range of multifunctional inks available for an integrated print process. This raises challenges such as printing with three or more materials, and finding inkjet printable materials that can be cured simultaneously using the same curing method. The aim of this research is to print functional structures using at least three materials consisting of a structural, support, and conductive material, requiring only one curing technique involving UV light exposure. An experimental setup of PiXDRO LP50 inkjet printers and various printhead assemblies are used to conduct experiments. Suitable off the shelf available inks are selected after a state of the art literature review. Stratasys Vero­series and Stratasys SUP706B are industry standard, compatible materials and cure using UV induced photopolymerisation. They are chosen as structural and support material, respectively. Novacentrix Metalon JS­B25P and Mitsubishi NBSIJ­MU01 silver nanoparticle inks are chosen as conductive inks. First, multi­material printing is set up and extended to 3D printing using the structural and support material inks only. Afterwards, conductive inks are tested for resistivity and behaviour on different substrates before integrating with the structural and support material ink into a multi­material 3D print. Conductive nanoparticle inks show good conductivity on photopaper substrate, but not when printed on top of structural material. Several experiments are performed to document ink behaviour and optimise performance. A workflow is designed allowing the conversion of complex CAD models to inkjet ­printable files. Custom support material density for stronger supports can be generated using an in-­house developed conversion application. Proof­ of ­concept multi­-material functional structures are printed showcasing success of the proposed methodology.