Around 9,000 detainees are held in Dutch penitentiary institutions, managed by the Dienst Justitiële Inrichtingen (DJI). These institutions are mostly old buildings, due for renovations from 2030 onwards. With increasingly warmer summers, heat stress among detainees and staff is growing. Effects of heat stress lead to negative impact on mental, psychological and physical wellbeing . Ultimately, these result in threats for the safety in the institution. With renovations starting years from now, effective measures to reduce heat stress are needed now already.

This study researched the factors that cause heat stress, and potential measures that could reduce this effectively. With a computer simulation that calculated heat flows for a cell in PI Zutphen, these measures are carefully compared to one another. The simulation incorporated technical and human factors, calculating both true temperature as perceived temperature. This way, all heat flows are tracked and show insights on different solution approached to cool down the detainees or the cell.

Reducing incoming solar radiation proves to be the most effective measure to reduce heat stress in cells. Additionally, this study points out that the current ventilation system is lacking behind, causing preventable heat stress. Improved and more frequent maintenance can solve this issue, and is therefore explored and elaborated. Besides these technical aspects, behavioural aspects are explored also. Increasing cleaning behaviour and providing knowledge on dealing with heat can lead to lower heat stress and more autonomy, which in turn betters wellbeing and safety in the PI.

Beyond the findings of this study, the computer simulation shows potential in becoming a valuable decision-making tool for DJI. This simulation can be iterated into a more comprehensive model that is to be used for renovation planning. Also, other indoor spaces and institutions can be simulated with it.

In conclusion, this thesis provides action steps wrapped in a roadmap for DJI to reduce heat stress before renovations. This will lead to improved detainee wellbeing and increased safety in the PI.

This thesis presents the design and validation of a low-cost, classroom-ready testing setup developed for the Understanding Product Engineering (UPE) course at TU Delft. While the course introduces first-year design students to material properties, limited access to hands-on testing has left key concepts like stiffness abstract and difficult to grasp. The project responds to this gap by creating a dual-purpose setup that supports both intuitive material exploration and structured mechanical testing.

Through iterative research and prototyping, a final design was developed: a compact three-point bending device with integrated force and deflection measurement, complemented by tactile tools for informal property investigation. Educational alignment was achieved by incorporating principles of Productive Failure and experiential learning, allowing students to confront their assumptions and engage with real-world variation in material behavior.

User testing showed increased student confidence and understanding of material stiffness, while mechanical evaluation confirmed measurement repeatability within a ±11.3% error margin and ~6% standard deviation across trials. The setup is now ready for integration into the UPE course and demonstrates potential for broader application in design education.

With the introduction of the new Industrial Design Engineering (IDE) bachelor in 2021 all courses underwent a revision to promote, amongst other, an autonomous learning attitude. The conventional approach of teaching engineering relied on direct instructions and problem-based learning and proved to be inadequate. With a short retention time and limited deeper concept understanding, students struggled to apply their engineering knowledge in capstone design projects. This project aims to develop new educational materials to align better with this new attitude.

The project is approached with a hands-on and iterative mindset. More than nine prototypes have been developed and tested with users. The result is a versatile educational toolkit that can be configured into small-scale manufacturing machines. Currently three configurations are developed, but due to its modular components more configurations can be added in the future. These machines provide students with hands-on experience related to manufacturing techniques and its opportunities, limitations, and materials. By being intriguing, exciting, versatile, and user-friendly, the machines stimulate active involvement. With a focus on producibility and cost-effectiveness, this toolkit is designed to integrate seamlessly into the IDE bachelor's program, offering an accessible, practical, and engaging learning resource that supports deeper concept understanding.

Each year, over 50 million tonnes of electronic waste is generated globally, with the Netherlands averaging more than 20 kg per capita (Compendium voor de Leefomgeving, 2023). The shift from a linear to a circular economy is crucial in addressing this issue, emphasizing the importance of durability and repairability in product design. Additionally, the forthcoming legislation from the European Commission (2023) regarding the “right to repair” highlights the need for designers to create products that are both durable and repairable. This project delves into a product’s durability, considering not only its physical repairability, but also how it can retain aesthetic value over time. Central to this exploration is the question: “How can appliances be re-designed for retainment, considering repairability and aesthetic durability?” Drawing upon literature research, a design space is formulated, guiding the several re-designs of the same appliance, in this case a sandwich maker, with each re-design focusing on a specific aspects of repairability and aesthetic durability theory. Evaluation of these re-designs by visitors at Dutch Design Week informed challenges, guiding the further development of one of the re-designs into a functional prototype. The literature review addresses repairability through the challenge of fault diagnosis, particularly as products are often perceived as ‘black boxes’. Practical design implications for improving ease of disassembly and part replacement, alongside the value of awareness of components in having a product repaired, are discussed. Aesthetic durability is explored from the perspectives of ‘living with things’ and the ‘life of things’. The former examines aesthetic pleasure from a multisensory point of view, and the role of familiarity and novelty in design. The latter discusses the dimension of temporality in product design throughout a product’s lifetime, and the concept of products becoming ‘things’ when they break down. The construction of a design space with three axes based on this theory—’the possibility to repair’, ‘our pleasure as users’, and ‘the life of the thing itself’—provides a framework for creating eight diverse prototypes reflecting various perspectives from the theory. Evaluation by 3010 Dutch Design Week visitors identifies one prototype, featuring an ‘oven mitt’-like top, as standing out for its emotional qualities such as ‘connection’ and ‘beauty.’ This re-design is selected for further development into a functional prototype, highlighting repairability improvements and offering the opportunity for ergonomic testing.

2022 SODAQ, manufacturer of the general purpose asset tracker: TRACK, committed itself to take environmental and social responsibility and got rebranded as a ‘World-friendly IoT’ company. A Life Cycle Assessment (LCA) for the current TRACK product, performed by an external company, proved that decreasing the impact of the enclosure might provide a good opportunity to significantly reduce the total impact of the product. However, two new ‘Fast Track’ LCAs showed that the plastic enclosure only contributed less than 5% to the total impact, with the electronics being responsible for the rest. Therefore the goal of the project was to reduce the impact of the electronics.
In this project an attempt was made to find a solution for the most impactful and relevant components such as the PCBA and the PV panel. First sustainability issues of the current TRACK components were identified and then the sustainable opportunities and limitations of alternative technologies were discussed. To show at what point in time the new technologies are expected to become relevant, technology roadmaps were created.
As a conclusion of this world-friendly technology research, a vision for the future of the TRACK line was laid out in a product roadmap. To show how the integration of the more world-friendly components could translate into practise, the TRACK Core 5G concept was designed as a showcase product. The TRACK Core 5G prototype includes a solvent-based recycled polycarbonate (PC) transparent enclosure, with electronics printed on a recycled substrate and a flexible emerging PV panel.
To extend the lifespan of the electronics, circular product design guidelines were applied. The basis of the circular loops is that the components can be disassembled quickly. In the current product the time it takes to replace the battery was relatively long (80 seconds) and the PV panel could not be replaced at all. By using the disassembly strategies and the choice for a 'direct access' design, all electronic components, including the PV panel, can be disassembled in 6-17 seconds.
In order to extend the life of the most impactful components, the chips on the printed circuit board, the theory of modular design was applied. By using the material properties of the flexible PCB, a new strategy for upgrading the PCB was developed which brings down the initial cost and
offers more flexibility.

This report presents the process of designing a volume unit as an addition to the current product system, which will allow the user to control boiling, chilled and carbonated water volumes. This assignment tackles both the user interaction that takes place around the tap over the counter, as well as the functionality and technology implemented below the counter to control the water volumes. One of the drivers of this project is backwards compatibility, making the designed system suitable for all existing taps and reservoirs.

Discover
Research is conducted internally at Quooker B.V. to identify the system characteristics when it comes to Quooker reservoirs, as well as the user interface and usability of the taps and accessories. Externally, competitors and other field applications are considered as inspiration for the design of the project. A set of use cases is obtained through exploration and user interviews, which serve as guideline for the design. Interestingly, users don’t frequently measure water volumes as they rather fill their pots by feeling based on the relative water level in the container. As for technology, after careful literature and desktop research, flow sensors, weight scales, pumps, timers and pressure sensors are considered.

Define
Based on the user needs and wishes, as well as Quooker system limitations, a list of requirements is created to steer the direction of the design process. These criteria include amongst others; usability, performance, aesthetic and cost price requirements. Some important aspects that are considered are limescale, flow rate, mental strain and the properties of special feature water, such as temperature, pressure and water consistency.

Develop
The next step is to explore different design directions. Several options are considered for both the user interaction and flow measurement, as well as possible placements within the current system to establish compatibility. These options are evaluated by users and R&D engineers and the final concepts were chosen; an external knob for over-the-counter user interaction alongside a turbine flow sensor at the inlet of the water system. These concepts are developed and tested within and outside of Quooker B.V. and iterations are made to improve the design.

Deliver
Finally, the part assemblies are laid out and design decisions are presented, as well as where the two units are placed in the system and how they are connected with each other. A cost estimation and preliminary manufacturing plan are presented to prove the feasibility of the design and future recommendations are made to assist Quooker B.V. with the further development of the product.

The incentive of this graduation project was to determine the repairability of Philips cordless vacuum cleaners and propose strategies to improve their repairability. This was done using two assessment methods; the Disassembly map and the French Repairability Index (FRI). The French Repairability Index is the first mandatory repair label. The final outcomes of this project are an assessment of two Philips cordless vacuum cleaners, a tool which provides guidance during FRI assessment (The adapted Disassembly Map) and design guidelines on how to design for FRI.

For healthcare, an industry that is currently responsible for up to 10% of the global carbon footprint, the transition to carbon neutrality and circularity will be an enormous challenge. As 20-30% of the total hospital waste originates from operating rooms, optimising recovery from these waste streams has the potential to make a significant improvement on the environmental footprint of the healthcare sector. However, the recovery of components from current surgical devices is difficult and laborious and thus redesigns are necessary. A gap in the literature is identified regarding design methods specifically targeting circular redesign of surgical devices. Therefore, this thesis aimed to develop a method that helps designers in redesigning surgical devices for circularity.
As a result, the Circular Redesign Focus Point (CRFP) tool is developed. The tool guides designers in making substantiated decisions on which components to improve the recoverability of, by redesigning the surgical device. Through the assessment of the device on a component level, a set of outputs is generated which are split in the categories disassembly effort and potential gain. Utilising this division the new Circular Redesign Necessity metric is developed, which is used to score the focus points for redesign.
The validation results indicate that the thesis aim is achieved by the development of the tool. With this, the novel tool addresses the identified gap in the literature. The tool forms the first design tool for circular surgical device design and provides a starting point for future studies in this field.

The popularity of shared E-bikes and sustainability is rising rapidly worldwide. The shared E-bike market likes to position itself as sustainable. Still, in reality, both faulty and decommissioned E-bikes get scrapped at enormous scales. This practice is far from sustainable. The problem with the existing shared bikes is that they are subject to rough usage while being expensive to maintain. Besides, the E-bike is inevitably subject to technical obsolescence resulting from advancing E-bike technology. We designed a durable modular E-bike with a circular end-of-life purpose. The E-bike's durability reduces the needed maintenance frequency. The E-bikes' modularity enables simple exchange and interchange of modules. This allows cost-efficient E-bike repair and alteration of modules. Future robustness of the E-bike is essential for long-term re-usability in a circular system. We designed the E-bike to be time-less by well recognizable E-bike aesthetics similar to a traditional bicycle. The retro-look will never get old and helps to sustain the desirability of the re-use of the E-bike throughout time.

The bicycle production company Accell-group N.V. aims to improve their bicycle assembly lines. The assembly of bicycles requires fastening a large amount of parts using a variety of fastening techniques. In the investigated situation, these assembly operations are performed on an assembly line. The goal of this thesis is to structurally improve assembly lines on assembly time, product quality, assembly costs, assembler workload and number of faulty bicycles. To achieve these goals, a 7 step method is developed to find the largest improvement opportunities of an assembly line, determine which movements of the improvement opportunities are sub-optimal, determine what the root causes of the sub-optimal movements are and to ideate solutions to eliminate these root causes. This minimizes sub-optimal movements during assembly. The developed method was tested by applying it to three assembly line operations, which resulted in a reduction of assembly time and improvements towards the stated goals in all three tested situations. The outcomes of the thesis are an overview of the most promising improvement opportunities of the investigated assembly line, the developed method and practically tested improvement suggestions for the investigated assembly line.

The human microbiome and its relationship to several diseases is a new and evolving field of study. The uterine microbiome can be used to predict the chance of success of natural or assisted pregnancy. Possible contamination of the uterine microbiome during sampling hinders the ability to make conclusions about the possible relation between it and (sub)fertility. The sample is likely to get contaminated by the bacteria in the cervix, as the uterus has a low abundance of bacteria compared to the cervix.
A uterine microbiome sampling technique is created that can take a sample without contamination from the cervix. The gynaecologist has control over the moment the product opens and the location of sampling. The sample can be used for modern microbiological research like Next-Generation Sequencing.
Functional prototypes of the sampling technique are tested in an In Vitro Test at Medical Microbiology and Infection Control Department of the Amsterdam UMC, location VUmc. The test delivered the proof of principle that the idea has potential to be able to take a non-contaminated sample.
Follow-up studies are recommended with a sampler specifically designed for research purpose. The goal of this test is on what the relation is of the uterine microbiome and (sub)fertility. Based on these results, the use case should be more specified to be able to design a sampler for commercial use. A commercial sampler is still for the future, but the proof of principle of the sampling technique shows that the idea has potential to sample the uterine microbiome without contamination.

A framework to implement social learning in online solutions for educational consultancy TinQwise