This thesis explores how bacterial cellulose based foams can be combined and architected to form a bio based material system. The project was carried out in collaboration with Foamlab, a startup that develops freeze dried bacterial cellulose foams as sustainable alternatives to synthetic foams.

Bacterial cellulose is a natural material produced by bacteria that forms a strong, water rich fibre network. During earlier research at Foamlab, a blended bacterial cellulose foam variant was developed that showed high formability during processing and a wide range of tunable mechanical behaviour. These properties made it suitable for exploring how different foam variants could be shaped, combined, and controlled within a single material system.

The aim of the research is to lay the foundation for establishing this bio foam as a material system. While the project initially focused on architecting the material through geometry, it became clear that combining different foam variants is equally important in defining the material’s behaviour. Architecting and combining are therefore treated as closely connected design actions.

The research follows the Material Driven Design approach and is positioned mainly in the early phase of understanding material behaviour. The project begins with a literature review on bacterial cellulose, architected materials, and related bio based foam research, combined with an analysis of Foamlab’s existing materials. Based on this, a clear research scope and design guidelines were defined.

The core of the thesis consists of experimental work and technical characterisation. Foam samples with different densities were fabricated using custom moulds and freeze drying. Compression and tensile tests were used to study mechanical behaviour and to measure the level of attachment between combined foam variants. In parallel, free exploration was carried out to investigate different ways of combining foams, including controlled interface formation and sequential fabrication methods.

The results show that foam density is the main factor governing mechanical behaviour, while material composition plays a secondary role. Because density can be controlled through processing, mechanical performance becomes predictable by design. Strong and reliable bonding between foam variants was achieved when processing conditions were carefully controlled, resulting in clear stepwise compression behaviour within a single object.

The research concludes with a demonstrator that applies the material system to an aircraft seat component, replacing conventional plastic foams with a bacterial cellulose based foam. The thesis provides a foundation for future research on scaling, long term performance, and application driven development of architected bio foam systems.

Cyanobacteria are photosynthetic microorganisms found in a variety of environments, including marine water bodies. Some species are able to perform biomineralization, producing minerals such as calcium carbonate (CaCO3) that may act as biocement. The biomineralization capability of cyanobacteria has already been explored in the development of Living Building Materials (LBMs), composed of an inert scaffold of sand and hydrogel, that contributes to CO2 capture.

The offshore industry is a significant user of concrete, contributing to 11% of the global CO2 emissions. Therefore, the application of cyanobacteria biomineralized materials is envisioned as a way to reduce CO2 emissions in this sector.

The cyanobacteria biomineralized material has been studied in the fields of construction and is applied in 3D printing, but its potential for offshore applications still needs to be explored.

This study aims to explores the proprieties of cyanobacteria biomineralized materials to catter some requirements of offshore applications, thereby contributing to a more sustainable practice. This was done by first recreating the material from other studies, assessing its mechanical proprieties and testing it in underwater conditions. This was followed by a tinkering process where material qualities (e.g., cyanobacteria optical density (OD), biomineralization/curing time, type of hydrogel, aditional coating) were adjusted to fullfill its purposes.

The impact of these changes were measured through submerging the material in seawater and assessing its mechanical proprieties.

The use of cyanobacteria at an OD of 2.4, resulted in the strongest material. Using agar as an hydrogel binder, countered the dissolvability of the material with a gelatine binder. On the other hand mechanical tests showed that the agar bonded material was significantly weaker than the gelatine bonded material. Adding a silicone rubber coating to the gelatine bonded material did not make the material resistant to seawater. A prolonged biomineralization time improved the strength of the material significantly but more exploration is required to determine if the biomineralization time is the result of this strength or the adjusted sand/medium ratio.

Overall, this study demonstrated that cyanobacteria biomineralized materials can be applied in offshore applications since the right cyanobacteria OD, binder, coating and biomineralization time are employed.

Namibia has been home to some of the world’s oldest ethnic groups since the dawn of civilization. One of these cultures is the Himba, often referred to as ‘the last true pastoral nomads’ of Africa. They are known for inhabiting the water scarce desert region of Kunene in Namibia for centuries. Now, various factors, including climate change and the absence of governmental support, are forcing the Himba population to decide which aspects of ‘modern’ culture to incorporate into their everyday lives.

After decades of declining rainfall and rising temperatures, drought and omakururukiro yokuti (over-utilized land and vegetation) are the reality. The Himba is therefore forced to rely on their nomadic origins for survival, and to travel southwards, ‘following the water’, to Windhoek which is the capital of Namibia. On arrival, they are confronted with inequality apparent in the African urban built environment and take part in the rapid urbanization of Windhoek. They settle in townships, in shacks, located on the outskirts of the city, where access to water and sanitation is limited. Due to landscape topology, climate change and other factors, the high possibility of flooding poses a new risk. Indeed a life-threatening choice: surviving drought in Kunene or surviving floods in Windhoek.