Airbus Cabin Vision 2035 aims to transform the future experience of air travel with a focus on sustainability through its three pillars: Transparency, Decarbonization, and Circularity (Airbus, Airspace Cabin Vision 2035+). As part of this initiative, the current thesis explores the potential of bio-based materials to replace conventional fossil-based thermoplastics in aircraft seating trims. By investigating whether nature can provide lighter and more environmentally friendly alternatives, this study seeks to reduce the aviation industry's carbon footprint (during the usage phase of aircraft) while enhancing the circularity of the materials.

This research is structured in a three-phase iterative framework. The initial phase involves problem analysis and the development of design specifications. The next phase, material exploration, identifies a list of potential bio-based materials suitable for design exploration, followed by a literature review to understand their flammability and moisture resistance properties, which are critical for compliance with the rigorous standards of aircraft applications.

From the material exploration, a family of hardwood, natural fibers, and mycelium emerged as potential materials for further design exploration. Lightweighting method was employed to optimize their geometry and meet the required mechanical strength established in the design specifications (Load bearing strength up to 100kgs). This method led to the development of a more practical option: the Designing of Composites. Static load-bearing capacity calculations were conducted to assess the feasibility of the composite design with the variations in facesheet materials. The pretreated Baxis Sinica wood panel with a mycelium core emerged as a feasible solution, primarily due to its weight-to-strength ratio, ability to meet the functional requirements of aircraft, and its circularity.

In the pursuit of material optimization, studies were undertaken in exploring bio-based coatings, to enhance the flammability and moisture resistance properties ensuring its suitability for the stringent requirements of aircraft applications. With established research on enhancing the flammability and water resistance of wood-based composites, the focus was to improving the properties of mycelium. Initial post-treatment methods using inorganic flame retardants like sodium silicate effectively demonstrated flame-extinguishing properties; however, further research is required to further enhance the material's water resistance. Additionally, there is promising potential for utilizing bio-based coatings to simultaneously improve both the flame retardancy and moisture resistance of mycelium. As it is well-established that bio-derived materials can degrade over time, it is crucial to develop strategies and treatments to ensure this does not compromise the product's lifespan. Current efforts also focuses on understanding the long-term behavior of these materials and their coatings under extreme conditions. However, as these materials have not yet reached full maturity, further optimization and enhancement remain within the scope of future research.

Positioned within the framework of Circular R-strategies, this study proposes an ambitious design, utilizing a wood and mycelium to develop a composite, with textile serving as the adhesive layer. The proposed design not only eliminates the need for fossil-based materials but also reduces weight by up to 50% compared to conventional thermoplastics in seat trims. This weight reduction is significant, as even a single kilogram less can lead to a decrease of 5,000 to 15,000 kg CO2 emissions over the aircraft's lifetime.

Direct ink writing is emerging as a sustainable alternative to conventional 3D printing techniques, promising significant reductions in energy consumption. This thesis presents a comprehensive investigation into the optimization of DIW processes, focusing on the development and evaluation of various ink formulations to identify the strongest recipes for producing materials suitable forprototyping within a circular economy. A systematic methodology was devised to produce test samples both by casting and printing. For the
DIW samples, achieving a balance between the required ink volume and the output volume was crucialto ensure consistent printing. Iterative adjustments to the g-code parameters and air pressure weremade to fine-tune the printing process, resulting in the production of samples for mechanical testing. Three-point bending tests were conducted on both casted and printed samples to evaluate their mechanical properties. Stress-strain curves obtained from these tests were analysed to determine the flexural strength and overall mechanical performance of each ink formulation. Among the various recipes tested, Carob combined with alginate emerged as the strongest, demonstrating mechanical properties comparable to those reported in existing literature. Confirming its potential as a viable candidate for use in prototyping.
The findings of this research underscore the importance of optimising both material composition and production parameters in DIW processes. By successfully identifying and validating an ink formulation, this work contributes to the advancement of sustainable 3D printing technologies.

This study explores nudging strategies to improve user abilities in order to promote the voluntary return of digital health products, with a focus on the smart pillbox. The two objectives were to create specific design recommendations for the smart pillbox and derive general design guidelines to support a circular lifecycle for future digital health innovations. The study revealed four key design aims: enhancing user abilities, establishing reliable return mechanisms, reducing participation barriers and exploring the wide range of potential applications.
The investigation combined thorough analysis, engaging users and refining designs through iterations. The key findings emphasized the crucial factors of product hardware design and strategic communication in influencing users' abilities and willingness to return the smart pillboxes. Innovations in designing smart pillboxes, such as state switches, clear printed instructions, and digital reminders, have been introduced. Preliminary validations suggest that they are effective, but there is a need for further research to explore their combined impacts. Interestingly, this research highlights the importance of "Returners" as crucial stakeholders in the product return ecosystem. This underscores the need for tailored comprehension and design to meet their unique requirements.
Although the recommended guidelines have the potential to benefit a wider range of smart health devices, it is essential to validate them with more extensive participant groups. It is worth noting that the current research mostly focused on user ability, however, future studies are encouraged to explore the motivation dimension, which participants identify as a critical factor. This would help create a holistic approach to encourage voluntary product returns.

With growing concern over our reliance on non-renewable resources and the environmental impact of conventional manufacturing, the quest for sustainable materials and production processes has intensified. This pursuit has extended to the field of additive manufacturing, where bio-materials have emerged as promising alternatives, aiming to reduce energy consumption and utilise material waste streams. While biopolymers like PLA are a good step forward, they still pose sustainability challenges, primarily related to energy-intensive melting processes, competition with food sources for production, slow biodegradability, and inadequate waste disposal systems. Consequently, researchers have turned to utilizing biomass waste streams to create 3D printable materials that solidify at ambient temperatures. However, the currently existing bio-based materials for ambient printing exhibit inconsistencies in quality. To allow for commercial adoption of these materials, enhancements in print quality are necessary.

This thesis addresses the core issue of lower print quality in room-temperature printing of biomaterials. Its primary aim is to develop and optimize the print quality of these materials, fostering a deeper understanding of the key factors that influence their printing performance. Within the context of print quality, the study examines parameters such as dimensional accuracy, bridging, overhang performance, warpage, corner sharpness, surface finish, and precision. Furthermore, the research investigated the feasibility of reprinting these materials and its impact on their print quality. Extra attention was dedicated to investigating the influence of the rheology characteristics of the materials on the resulting print quality.

The research led to the creation of two materials, AB1 and CLAB4 and the optimization of print parameters to enhance their print quality. In doing so it elaborates on the influences of material composition, preparation and printing parameters on the print quality of biomaterials printed at room temperatures.
Of the materials developed, AB1 demonstrated exceptional bridging capabilities, achieving distances of up to 15 mm, minimal shrinkage (averaging 6% in the xy-directions and 4% in the z-direction), and good result precision. In contrast, CLAB4 excelled in surface finish, printing overhangs up to 40 degrees, and showcased higher efficiency in material preparation. Most noteworthy of both materials is their reprintability without evident degradation in print quality, a crucial feature for sustainable printing methodologies.

In this Research, rheology characteristics have proven to be pivotal due to their direct influence on material flow and behaviour. Unlike conventional melting-based printing, where materials flow upon heating and solidify once they are extruded, ambient printing requires inks to have specific rheology behaviours caused by changes in shear. Rheology governs how easily the ink flows when extruded and its ability to retain shape once extruded. Optimizing the shear-thinning behaviour and elastic recovery behaviour is crucial. This study elaborates on the specific aspect of rheology to improve enhancements in print quality, including Yield stress, flow stress, storage modulus, loss tangent and thixotropic response and recovery. Additionally, it presents interesting insights into how to optimise them based on material composition and preparation. Mixing the material before extrusion, for example, was shown to significantly increase the thixotropic response time, leading to more precise extrusion.

Radiology department at the Leiden University Medical Center (LUMC) aims at preventing ultrasound gel waste of leftover ultrasound gel in the bottle and reducing the waste of plastic gel bottles. The study identified a critical environmental issue – the excessive use of disposable plastic ultrasound gel bottles in hospitals – and undertook a multifaceted investigation to address this challenge. Through examination of the environmental impact, user feedback, and risk factors associated with alternative solutions such, the research presented three sustainable redesign proposals. Among these, the gel pack design emerged as the most promising option, offering substantial improvements in environmental sustainability without compromising usability or patient safety. Successful implementation of these solutions relies on collaborative efforts involving doctors, regulatory bodies, and industry stakeholders. This research underscored the vital role of sustainability in healthcare and highlighted the potential for significant reductions in environmental impact and plastic waste while upholding healthcare standards.

While Additive Manufacturing is famed for its ability to create complex geometries, sustainability of the technologies is given less attention. Due to the need to melt filament and heat up the printbed, FDM requires a considerable amount of energy. On top of that, valuable and non-renewable resources are used for the production of the commonly used filaments. There is a need for materials that are suitable for FDM printing, while being less detrimental for the environment than commonly used plastic filaments. In this project, paste-like material mixes are developed and tested for their suitability for FDM printing in order to see whether they have the potential to make FDM more sustainable.

Consumer products produced in contemporary times face the issue of deteriorating durability, repairability and service life compared to products of yesterday. This deterioration is part of a bigger issue called planned obsolescence. Due to a ‘need’ to buy new products regularly, there is rampant consumerism which has created a decrease in raw-materials and an increase in the products and materials entering the waste streams. Therefore, it is imperative that this “cradle-to-grave” model is stopped. The EU and various governments in the EU have proposed legislation to transition from today’s linear economy to a circular economy. As part of that, there is greater emphasis placed on a product’s repairability, durability and product lifespan.
Repair scorecards are used to evaluate products on those parameters. However, the current scorecards have abstract scores that are difficult to interpret. Therefore, this thesis proposes a quantitative tool that calculates the total cost of ownership (TCOO) and service life of a product by modelling product lifetimes using failure modes.
This thesis begins with performing a literature study of linear economy and planned obsolescence, current scorecards, and their limitations. Questionnaires and interviews were conducted to understand what consumers wanted from a repair scorecard. The results from these were used to design the label and website of the TCOO tool. A system was created to facilitate the TCOO Excel tool, label, and website.
The mathematical model to calculate the TCOO was built-in to an Excel tool, and sample data was used to iterate upon them. Sensitivity analysis was also conducted to test the Excel tool. User tests were conducted to test if the Excel tool was intuitive to use and the flow of the tool iterated upon. User tests were conducted to refine the design of the label and the website.
The main contribution of this thesis lies in presenting the factors of repairability, durability and product lifespan in terms of cost, modelling product lifetimes, and moving from a priority component-based calculation system to a failure mode-based system. Using this tool, consumers can make informed purchase decisions, and manufacturers get data regarding failure, and legislators get data to introduce new laws and mandates.

With the increased market share of bifacial modules, it is becoming increasingly important to have sensors that provide information about the irradiance falling into both sides of the modules. Such instruments give more information about the performance of PV modules. They can optimize the material, tilt, and orientation of PV modules according to the surface on which they are installed. However, most sensors in the market do not provide spectrally resolved data, and the ones they do can be expensive.

Because of the preceding, this thesis aimed to design and fabricate a cost-effective spectrally resolved albedometer that will measure the global and reflected irradiance in three different parts of the solar spectrum using photodiodes as sensing elements. This thesis demonstrates how the device's optical, electrical, and mechanical characteristics can be optimized to obtain a more accurate estimation of the spectral albedo.

Additionally, a bio-inspired casing design with self-shading properties was created to reduce the temperature inside the device. Two prototypes were fabricated with two different colour-diffuser configurations (Grey-N-BTK diffuser and White-Hybrid diffuser). Data measured by the final prototypes was calibrated and validated with measurements from an EKO MS700 spectroradiometer. The final sensors have an average error of 20.4% and 7.3% and operate at 17ºC and 8.6ºC above ambient temperature. The albedometers have a volume of 810 cm2 and cost around €978.

IMO - Millennium is a smart, modular au- dio mixing system. It is designed to cater to the music routing needs of a modern household. High fidelity, uncompromising, analogue audio pathways mixed with digital controls. Aesthetics that compliment music equipment of any era, and materials that
will last for ever. Starting off with two audio inputs and one output, it can also expand, with the installation of additional audio mod- ules, in order to accommodate more audio sources. Moreover, with extension plug-ins, it can support music protocols other than a raw audio signal, in order to keep up with new technologies. Those form fitted blocks can introduce Bluetooth, AirPlay, Optical, or even Phono Pre-amplification functional- ities and so on. Wi-Fi connectivity enables remote control of the console’s motorised volume knobs, through a mobile application. IR receivers and transmitters, hidden out of sight, can identify pattern signals of tradi- tional remote controls and replicate them, gaining this way control of other devices in the room. Each audio channel is also equipped with a customisable button and its function can be programmed to the users liking.
Sustainable design, with minimised environ- mental impact and great repairability. IMO is using a short bill of materials, most of which are either already recycled or great for recycling at end of life. Reversible fasteners are dominating the structure, without the use of any destructive adhesives. The sim- ple assembly of the housing and the elec- tronics, make repairs easy and essentially fool-proof. A single HEX key (Allen key), is needed to fully dismantle the entire product. Common, off-the-shelf electronics, that are easy to understand and identify, are used for the internal circuits. Internal circuitry communications are handled by connectors widely available to the public, making re- pairs even more manageable.

The fashion industry is one of the most polluting and wasteful industries in the world. This is strictly related to the linearity of its production model, which puts profit and product generation before environmental and social sustainability. Very often this leads to overproduction and huge amounts of waste created. Specifically, the fashion industry that designs clothes made of synthetic fibers faces also the struggle of recycling the material into new clothes, due to technological backwardness and lack of proper systems that could implement it.

Maium is an Amsterdam-based fashion company that produces recycled PET raincoats and that highly values sustainability in its practices, wanting to lead as an example for other fashion brands.
Market and brand analysis (through tools such as 4C analysis and SWOT analysis) are the starting point of this research, which aimed at analysing Maium’s environmental impact through Life Cycle Assessments and finding more sustainable alternatives to their current production model. The design process consisted in applying tools like VentureWell’s Whole System Mapping and Presidio Sustainability Booster to the results of the LCAs. The process has been an iterative one, so as to best define pain points and opportunities, and thoroughly think of the possible solutions that could be implemented.
The design solution has the intent of including the final users in the clothes’ lifetime extension process by teaching them techniques and skills that they can apply to their raincoats and to other pieces of clothing as well. Moreover, the intent has been also to provide them with as much information and transparency as possible for what concerns the production processes, the supply chain and alternative business models to the linear one.

This report contains the graduation project of Linde de Jonge in collaboration with Paviljoen 3, and aims to find a solution to reducing the eco-footprint of existing homes, by combining solar panels, green roofs and heat pumps in a modular fashion to be adaptable to the specific requirements of each household and complement the working of each individual system. Method User research, market analysis, creative sessions and observational studies have been implemented to support the iterative process towards a solution. The creative process was divided in three cycles. The focus of the first cycle was to find a solution with high feasibility for the company, by combining products on the market and adding small but crucial design intervention to create a unified system for flat roof surfaces. The second cycle aimed to create a solution suitable for tiled roofs, which is exceedingly common in the Netherlands, yet thus far incompatible with a green roof. The focus was on creating a solution which would enhance the exterior of the building, to increase the desirability of the design (an opportunity based on client research). The two cycles resulted in two concepts with a very opposing solution approach. These concepts were presented to the company and a selection was made. This selected concept was the start of the third cycle. In this cycle, the feasibility is established by detailing the embodiment of the system. Furthermore, the viability is illustrated by a future development roadmap. Design This project’s main challenge can be summarized as finding the balance between: 1. introducing an entire roof-system to market; 2. without losing the flexibility in the wide range of products (PV, heat pump or green roof) available to fit the variance in client and household needs; 3. and with the least amount of in-house produced parts to fit the company’s resources. The solution of this project is an entire roof-system, consisting of market available components and components proposed to be developed and manufactured by the company Paviljoen 3, which are implemented into the system according to distinct development phases. By combining existing products on the market, solely introducing components which are crucial for the viability of the roof-system and separating the innovation of system’s components into separate phases, this solution diffuses the investment costs for P3, while enabling them to acquire empirical insights concerning the system, which they can apply in further system development. They can have intensive prototyping and experience using market-bought products, before they invest in launching their own product. The design cycle ends with a final prototype of the developed components, and a company evaluation. The report concludes with a list of recommendations for the company to pursue further concept development.