Exploring Bio Foam

Abstract

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.