The low frequency radio waves of 10 kHz to 30 MHz are in a frequency band that is hard to measure when on Earth. As this frequency band holds information about the very start of the universe, scientists are eager to do measurements. Together with the TU Delft Space Institute, dr. ir. Chris Verhoeven wants to set up a mission of a swarm of 50 12U-CubeSats that orbit the moon. The difficulty in measuring these radio waves lies in the required antenna length of 5 metres, while having extremely limited storage space within these CubeSats.

Over the past decades, several types of antennas, such as inflatables and origami-structures, have been studied and researched in order to develop one that can be deployed. Yet, no applicable antenna for CubeSats has been designed to sufficiently measure these radio waves.

In this thesis, a solution to this problem is proposed. Based on calculations, simulations and tests, an antenna is evaluated and improved upon. The end result is BEAD, a Beaded Expanding Antenna Design. BEAD is an antenna consisting of several parts that are connected and tightened with the help of a copper wire. Six antennas of 8.8 metres can be stored in one 12U-CubeSat. BEAD is a stiff and strong design that can handle manoeuvres of the satellite. At its end-of-life stage, the antennas can be retracted to minimise negative impacts.

This research investigates the challenges a user faces in the activation step in shape-changing products. First, previous research on the topic of 4DP is reviewed and important factors are described. Namely, activation temperature, print temperature, print speed, and layer height have a signifi cant impact on the shrinkage of SMPs, during the activation step in 4DP. These shrinkages can be applied to an object through the use of varying strategies. These strategies show there are two ways of applying SMPs to a design, either calculate the shrinkage or create limits with the use of geometry-based end stops. Lastly, a further review is conducted into the type of products made with 4DP. These products turn out to be made out of three categories; fl at-packed, custom fi tment, and energy-absorbing structures.  The second chapter, Material Tinkering & Exploration, delves into the material characteristics of LW-PLA, showcasing its utility for shapechanging. LW-PLA can be used both as a passive and active element, reducing environmental impact by enabling or disabling shape memory through micro-scale structural changes. This material is then used to fi nd a correlation in curvature and ratio of active versus passive elements within a design. Furthermore, the material is used to fi nd the best type of heat source, trying to create the most consistent outcomes. The oven without convection is then chosen as it creates the most consistent outcomes by limiting user interaction and making use of slower response times.  The following chapter brainstorms ideas that can make use of shape change. Through the use of criteria and Edison profi les a direction is chosen. This is the direction of the temples of glasses. Shape change can add to this product as the temples vary in length to fi t different users. This chapter also creates two prototypes to be tested, differing in the type of measurement method.  Lastly, the design is evaluated through the use of two user studies. In the fi rst study, the focus is laid on the type of measuring method. The external measurement method comes out as the most promising as it creates the most consistent outcome with the users. The second test tries to minimize the error between the targetted length of the temple and the actual length after the activation process has ended. The result is an addition of two test samples that educate the user. Through the education of the user, a consistent result with minimal error can be achieved. The activation step also requires a homogeneous method of heating the temple, small deviations in this heating lead to unwanted curvature. This is combatted by creating a tray, that is delivered together with the temple.

Recent advancements in Additive Manufacturing (AM) suggest that Multi-Material Jetting (MMJ) could create materials with interactive properties that encode digital information readable by computers. However, it remains unclear if these opportunities are compatible and how they could integrate effectively in designs for tangible interaction and Extended Reality (XR). Building on the concept of Radical Atoms (Ishii et al., 2012), this research explores how MMJ might connect physical interactions with digital information through materialization. A literature study was performed to examine how multi-material 3D printing could enable XR systems to capture and interpret physical manipulation, particularly addressing challenges in XR and Tangible User Interfaces (TUIs). A unique solution space for MMJ was identified, envisioning Stimulus-Responsive materials capable of converting physical stimuli into fiducial responses for computer vision. To assess the feasibility of this embodied approach for TUIs and explore potential interactions that can be achieved, a “Research through Design” methodology was applied. The proceedings document the design and development of Colorful Bits: a Stimulus-Responsive material for kinetic interaction. Colorful Bits present a configurable Stimulus-Responsive material which captures kinetic interactions as a dynamic fiducial color response. By interlinking mechanical and optical properties through material and structure, a mechanical metamaterial is designed which transforms movement, orientation, and kinetic deformation of objects to color-encoded information. Through the physics principle of superposition, the applied stimuli that cause the movements and deformation can be obtained, allowing for force-, stress-, and pressure-sensitive interactions. By applying this process, designers are enabled to design kinetic materials for XR that provide virtual feedback in response to applied kinetic deformation. Evaluations of Colorful Bits reveal promising insights into the viability of Stimulus- Responsive materials for TUIs, though current gaps between digital models and real-world behaviors limit full application. While Colorful Bits focuses on kinetic interactions, future applications are envisioned that expand fiducial Stimulus-Responsive materials to respond to environmental stimuli such as temperature, light, and moisture, positioning MMJ as a versatile platform for XR applications.

Fluidic interfaces use liquids to sense, compute, and output a dynamic appearance or behavior in response to mechanical deformation inputs.
Integrating logic and user-actuated control mechanisms in the interfaces can, in the future, enable to achieve more complex dynamic behaviors for designing interactive artifacts that are entirely analog and fluidic driven, opening the space for more nuanced interactions to be envisioned and integrated into the artifacts.

Employing material jetting 3D printing as a manufacturing process, the project aims to expand the design space and computation & interaction possibilities of fluidic interfaces as programmable (meta-)materials, by expanding the possibilities of user-controlled interaction with the artifacts.

As final outcome, two prototypes with programmable dynamic appearance and tangible, user-actuated controls are developed, showcasing the capabilities of fluidic interfaces and the possibility of designing these artifacts for specific user-controlled experiences.
The potential future applications of fluidic interfaces are explored through the application of the Context Variation by Design methodology, and expert interviews, applying the Material Driven Design approach. This investigation lays the foundation for further research and practical implementations in the field of interaction design.
Through the exploration of logic implementation and tangible control mechanisms for 3D printed fluidic interfaces, this master thesis aims to generate valuable knowledge for the field of HCI (Human-Computer Interaction) and Digital Fabrication, highlighting the possibilities and challenges of integrating fluidic interfaces into future applications.
The project contributes to the ongoing research on meta-materials and Tangible (analog) User Interfaces in HCI in the hope of inspiring new research and design initiatives that can lead to the integration of this technology in people’s life.

The widespread proliferation of cellular lattices in engineering design has entailed a revolution in the design of lightweight and multifunctional structures. Furthermore, the development of auxetic metamaterials has led to applications in fields ranging from biomedical to civil engineering. However, cellular lattices suffer from the development of localized concentrations of strains during deformation, which lead to sub-optimal mechanical performance. Furthermore, the mechanical properties of cellular lattices are dependent on their macro-scale geometries, limiting their design space. Thus, we seek to both enhance the mechanical properties of lattices by ameliorating strain concentrations and expand the design space of cellular lattices.

In attempting to do so, we can turn to nature. The bio-inspired design motif of the hierarchical arrangement of composite materials has lead to exceptional mechanical characteristics in natural materials. Moreover, morphogenetic processes such as bone remodelling play a vital role in the structural development of natural materials and their hierarchical material arrangement. Motivated by these concepts, we developed an algorithm that optimised the hierarchical material arrangement of hard and soft voxels in an auxetic and non-auxetic unit cell. Our algorithm does so based on a bone remodelling-like approach of strain energy optimisation, whereby elements are transitioned to a hard or soft material based on local strain energy.

Our finite element (FE) simulation results demonstrate the considerable expansion of the range of mechanical properties we can achieve simply by modifying material placement on a micron scale. We also observe clear mitigation of peak strain energies and more homogeneous distributions of strain energy density, which affirm the amelioration of strain concentrations. Furthermore, we were able to increase the stiffnesses of our unit cells without substantially affecting its Poisson’s ratio, disentangling previously interdependent mechanical properties. We further validated our FE simulations by additively manufacturing our optimised unit cells with state-of-the-art voxel-based printing. Both the mechanical properties predicted by our FE simulations and the strain distributions correlated well with digital image correlation recordings, validating our models. Our mechanical testing also revealed the considerable in- creases in ultimate tensile strength of our optimised designs, demonstrating the benefits of hierarchical material arrangement.

To conclude, we demonstrate the efficacy of strain energy-based material optimisation to improve the mechanical properties of unit cells and mitigate strain concentrations. The design paradigms of hierarchical arrangement of composite materials remarkably improved the material space of a unit cell without changing its macro-scale geometry. Findings from this study could enable the optimisation of existing cellular lattices and the development of novel unit cell designs with distinct intrinsic mechanical properties.

Magnetic soft materials are a newly developed material that can transform into programmed shapes when it is placed in an external magnetic field. It is made out of silicone with embedded magnetic particles that lay in magnetization patterns due to 3D printing them under a magnetic field. Its characteristics are fast, remotely controlled, reversible and heatless shape transformations. Because the material is new, not much is known about the parameters, how they are made or how they influence the performance of the material. The number of possible applications for this material is also very limited. This graduation project has addressed both these topics by using factorial designed experiments to understand different parameters of the magnetic soft material ink as well as starting the setup of the 4D printer system with which the material can be fabricated.

A design process was also done in which new idea directions have been identified. These were haptics, personalized fits, texture change, replacement of vulnerable mechanical parts, milli devices and scaffolding, and toys. A concept for a demonstrator was made to explain the material to designers and researchers and inspire them. It was a cleaning tool for hard to enter spaces. In the ink development, the influence of different ingredients was discovered as well as how they influence the viscosity of the ink, which is an important factor for the 3D printer system. The viscosity of the last measured ink, which was magnetized, was 500% higher than the viscosity limit of the 3D printer system. The 3D printer system should therefore be reconsidered for a new research project. In the end, also a proof of principle was made which showed the feasibility that magnetic soft material can be made.

This graduation project is the starting point of magnetic soft material at the faculty of Industrial Design Engineering. Even though the first parameters have been researched, much work remains to be done to fully understand magnetic soft materials.

The research described in this thesis explores the field of 3D printing technologies in the fabrication of printed, flexible tactile sensors and explores new possibilities and opportunities in the fabrication. The research is aiming at new ways of applying 3D printing fabrication techniques to develop easily applicable sensing structures to flexible, wearable applications.

Exploration into sensing principles and sensor designs for the printed fabrication of these tactile sensors results in the main design drivers of piezoresistive sensing and capacitive sensing to act as sensing mechanism for the developed sensors.

Fabrication principles are selected according to design thinking methods, and select and evaluate the trace design, substrate selection and 3D printing technique used in defining a concept proposal.

The performed exploration and design selection result in the concept proposal of a 3D printed tactile sensor using a TPU-coated nylon fabric substrate and ink-dispensed sensing structure using a Voltera V-One 3D printer. The sensing element is embedded into the fabric using heat sealing. A scalable, adaptable sensing array is proposed to allow for embedded tactile imaging capabilities.
The developed tactile sensor is validated by analysing a characterisation of the sensor readouts. A validation setup using a loadcell and vertical load is used to allow for the plotting of the sensors’ characteristics and linearity.

Validation shows evidence of significant measurement repeatability, while showing less proof for precise accuracy and resolution. Additional work needs to improve physical durability of the traces and connections.

The research concludes in a foundation towards the use of the 3D printing technologies of ink jetting/-dispensing to develop embedded sensor to be used in a large variety of tactile sensing/imaging applications.

Previous research proved the potential of using mussel shell waste as additive manufacturing (AM) material. In this thesis, mussel shell powder was combined with sodium alginate, since it allows reversible cross-linking. Due to reversible cross-linking, this water-soluble and recyclable material can temporarily be made water-resistant, so it can be used for applications that need to be water-resistant. In this thesis, this material was researched, improved, and eventually used to print a prototype of a parametrically designed plant-specific planter.

This project contains the graduation project of Fokke Jongerden as part of his curriculum of the master Integrated Product Design at the TU Delft. The project consists of a reflection and redesign of the Air-Wave.org Protector (AWP), a respiratory protection device designed by the non profit Air-Wave.org. The AWP is developed to protect hospital staff that cares for Covid-19 patients from contamination. The trajectory from idea concept to product implementation into hospitals, a process which normally takes several years, only took 8 weeks for the AWP. Many design and management decisions contributed to this success, which this project aims to analyse. This project has two goals: Crisis Design analysis In this part, the process that resulted in the Air-Wave Protector is analysed, and the strengths and weaknesses of this process are determined. Firstly, the entire timeline of the project was mapped to create an understanding of all activities of the development process. The relation and codependency between management related activities and design development were analyzed and critical moments to the project’s outcome were established. Secondly, the management method of the AW.org was studied, to identify the key elements of their management approach. These elements were compared to integral aspects of crisis design according to literature. This resulted in the distinction between methodized crisis management with the focus on threat control, and a newly formulated model for crisis opportunity management. Thirdly, the desing method of the design development team of Air-Wave.org was analysed. Their applied model was deducted, and insights were generated on the benefits and weaknesses of their approach. Lastly, the analysis was supplemented with a research on user appreciation of the end product of the management and design methods; the Air-Wave.org Protector. By pinpointing the strengths and weaknesses in the design, a reflection was made on missing elements in the approach of the organization. It was concluded that the use of repurposed elements in the design was one of the key factors in achieving fast market implementation. However, future projects could benefit from a context analysis, an explorative study to search for existing products to repurpose, in combination with a predefined List of Requirements to evaluate both developed and repurposed product components. AWP Redesign The second part of this project proposes a redesign of the Air-wave.org Protector. This redesign is based on literature studies, user research, method analysis, empirical insights gained during the development of the previous design and extensive prototyping. The result is a respiratory protection mask which can be interchanged with the current mask used in the AWP. The remaining product components remain unchanged. The new mask improves the field of sight, the comfort and the ability to communicate, both verbally and non verbally. Furthermore, this design allows the user to wear glasses. A functioning prototype was developed and user evaluation was performed. The report concludes with recommendations on future concept development.

With the introduction of the RepRap 3D printers, capable of printing most of its own parts, the cost of 3D printers dropped radically, making it an affordable and accessible technology, even for low resource settings. It is said that 3D printing can greatly increase accessibility to medical equipment in low resource settings because it enables local production and radically reduces costs. Within the Delft Global Initiative there are several research teams experimenting with the use of 3D printing for local production of low cost medical equipment in Sub-Saharan Africa. They quickly discovered that 3D printing in this setting is not as easy as it might sound. For one, the operating conditions were found to be much harsher in African, than in Western settings. According to researchers from Penn State University, current 3D printers lack in user-friendliness and robustness required to impact rural healthcare. Therefore, the goal of this project was to (1) identify the challenges for 3D printing in Sub-Saharan Africa, and (2) develop a final design proposal for a 3D printer for healthcare in this setting. The project started with an extensive analysis phase, where Kenya was chosen as a case study of a Sub-Saharan African country. The goal of this phase was to get a deep and qualitative understanding of the context of Kenya, and identify important implications for the design. In the design phase, an extensive amount of time and effort has gone into finding solutions for the challenges identified during the analysis. Solutions were developed to make the printer (1) able to operate on an unstable grid, (2) able to deal with excessive dust and high temperatures, (3) maintain a maximum printing uptime, (4) allow the printer to be used by anyone and finally (5) to allow the printer to be compactly transported. The first deliverable is a list of valuable insights that provides a deep and qualitative understanding in the context of Kenya in relation to 3D printing. This can primarily be used for the development of a 3D printer for low resource settings, but might also be valuable for initiatives working on closely related products in a similar setting. The second deliverable, in the form of a final design proposal, consists of a Prusa i3 printer adapted to fit the context of Kenya. It features a flexible power supply with backup battery, protection against dust and high temperatures, an automatic part ejection system, easy use through smartphone and lastly it is can be compactly transported and quickly assembled. The design proposal was evaluated by a panel of experts from Kenya and the US. They rated the final design to fit the intended user and context very well, but also stressed that it could be tailored more to the healthcare sector. The proposal was considered a better solution than what is currently on the market. More work should be done in the field of usability.

This thesis covers the design, implementation, and manufacturing methodology of a custom mouthpiece for the automatic toothbrush in development by Dental Robotics. The results are a proof-of-concept digital processing pipeline, a functional prototype, an evaluation of custom mouthpiece efficacy relative to the standard mouthpiece, and a recommended manufacturing setup.

This master thesis is the result of a graduation project for the Master Integrated Product Design at the TU Delft. The project was formulated as a continuation on research done by Mariet Sauerwein and Zjenja Doubrovski, in which they proved the potential of mussel shells as a material for material extrusion 3D printing. This with the aim of creation of a locally available material from a current waste stream, exploiting the possibilities of local manufacturing with 3D printing, as this has the potential to contribute to a circular economy.
This project was meant to continue the search for a material made from mussel shells that was printable and recyclable, and find possible applications.
Based on the literature and initial tests was concluded that an additional ingredient was required besides ground mussel shells and water, to create the right viscosity. Research was done into suitable binder materials. Four potential materials were chosen with a weighted criteria method. These materials were sugar, potato starch, iota-carrageenan and NEO-alginate. These four were tested on their effect on the printability and recyclability of the material. Both sugar and NEO-alginate were chosen to continue with as they both had proven to be the best suitable binding agents according to a set of defined criteria.
Relevant technical characteristics of both material combinations were defined by material tests. As the material is developed in this project, there is a certain amount of control over its characteristics by varying certain parameters in the process; Because of this not only the characteristics themselves but also the effect of process parameters was defined. The experiential characteristics, i.e. how the material is perceived, were defined by user tests.
Based on found characteristics a Material Experience Vision was defined. This Vision was meant to give direction and provide guidance through to the ideation process. The Vision is defined as
“I want to create an application in which the material has clear benefits over other suitable materials and fits within a system compliant with the principles of a circular economy. This application will comprise physical interaction with the user, to evoke found positive surprise due to the materials characteristics that differ from materials the user initially associated developed material with.”
With this Vision as guidance three product applications were found through the ideation process. From these three the concept Circular Lighting was elaborated on; in this concept the material was used to create lamp shades in a ‘light as a service’ system. This system was meant for circular built tourist residences. The manufacturer keeps ownership of the light system. Repair and replacement is outsourced to local parties, who would collect the material of the lamps and use it to print new lamps, creating local material loops. A prototype is made of a possible lamp design to validate and showcase the possibilities with developed material.¬