Agarose gel as a soil analogue for the development of advanced bio-mediated soil improvement methods

Bio-mediated soil improvement methods (those that use biological processes) have potentially low cost and environmental impact but can be difficult to control to ensure effective results, especially if engineered bacteria are used. A novel application of using agarose gel as a soil analogue is proposed, which can enable development of advanced bio-mediated soil improvement methods by reproducing relevant mechanical properties while allowing complex biological processes to be studied in detail, before testing in soils. It is envisaged that agarose gel will be used instead of soil when developing early-stage prototype methods, as it provides an ideal environment to facilitate growth and monitoring of bacteria. A programme of geotechnical tests and Scanning Electron Microscopy on Agarose Low Melt (LM) gel is presented. The results demonstrate comparable pore size, undrained strength and permeability to soft clays and peats but more linear stress-strain behaviour and higher compressibility. This paper offers proof of this novel concept but further investigation is required as only a single type of agarose, at a single concentration is tested. By varying these factors, along with use of different solvents, there is significant potential to tune the behaviour of the analogue to particular soils or construction scenarios

Bio-materialism: Experiments in biological material computation

In his article ‘Towards a Novel Material Culture’ Menges traces the origins of contemporary computational and fabrication techniques in architecture to ‘New Materialism’. Developed by thinkers such as Manuel DeLanda and Jane Bennett, the philosophical school characterizes matter as active and “empowered by its own tendencies and capacities”. In architecture, New Materialism has often become associated with biomimetics. However, over the past four years we have been developing a series of projects that take inspiration from the New Materialist paradigm, but that aspire to develop demonstrators and technologies which go beyond biomimicry and make direct use of living systems, designing through the manipulation of living cells

Designing a Living Material Through Bio-Digital-Fabrication: Guiding the growth of fungi through a robotic system

Designing with living materials require designers to look for new methods of fabrication since living cells exhibit their own agency, and are able to sense and respond to environmental stimuli. Therefore, there is an urgent demand to design a framework for fabricating living materials. This paper investigates the digital-fabrication of fungi as a new way of designing and crafting living materials without genetic manipulation. In this research, fungi act as a bio-material probe to generate and test new design strategies that enable a dialogue between digital and biological systems. Conceptual experiments, that use fungi to investigate the proposed bio-digital-fabrication scenarios, are central in this study. The research attempts to generate new information for the design process of an organism in the field of architecture. The project will expand on the latest thinking on the bio-material fabrication by allowing the living material to be engaged in the fabrication process

Bacterial spore based hygromorphs: A novel active material with potential for architectural applications

This paper introduces a new active material which responds to changes in environmental humidity. There has been a growing interest in active materials which are able to respond to their environment creating dynamic architectural systems without the need for energy input or complex systems of sensors and actuators. A subset of these materials are hygromorphs which respond to changes in relative humidity (RH) and wetting through shape change. Here we introduce a novel hygromorphic material in the context of architectural design, composed of multiple monolayers of microbial spores of Bacillus subtilis and latex sheets. Methods of fabrication and testing for this new material are described, showing that small actuators made from this material demonstrate rapid, reversible and repeatable deflection in response to changes in RH. It was demonstrated that the hygromorphic actuators are able to lift at least 150% of their own mass. Investigations were also extended to understanding this new biomaterial in terms of meaningful work

Are Mushrooms Parametric?

Designing with biological materials as a burgeoning approach in the architecture field requires the development of new design strategies and fabrication methods. In this paper, we question if designers can use a parametric design approach while working with living materials. The research uses fungi as a biomaterial probe to experiment with the parametric behavior of living systems. Running design experiments using fungi helps to understand the extent to which biological systems can be considered parametric and, if so, what kind of parametric systems they are. Answering these questions provides a method to work with complex biological systems and may lead to new approaches of fabricating materials by tuning the environmental parameters of biological growth

Turbulent Casting: Bacterial Expression in Mineralized Structures

There has been a growing interest in living materials and fabrication processes including the use of bacteria, algae, fungi and yeast to offer sustainable alternatives to industrial materials synthesis. Microbially induced calcium carbonate precipitation (MICP) is a biomineralization process that has been widely researched to solve engineering problems such as concrete cracking and strengthen soils. MICP can also be used as an alternative to cement in the fabrication of building materials and, because of the unique process of living fabrication, if we see bacteria as our design collaborators new types of fabrication and process may be possible. The process of biomineralization is inherently different from traditional fabrication processes that use casting or molding. Its properties are influenced by the active bacterial processes that are connected to the casting environment. Understanding and working with interrelated factors enables a novel casting approach and the exploration of a range of form types and materials of variable consistencies and structure. We report an experiment with partial control of mineralization through the design of different experimental vessels to direct and influence the cementation process of sand. In order to capture the form of the calcification in these experiments, we have analyzed the results using three-dimensional imaging and a technique which excavates the most friable material from the cast in stages. The resulting scans are used to reconstruct the cementation timeline. This reveals a hidden fabrication/growth process. These experiments offer a different perspective on form finding in material fabrication

Biofilm inspired fabrication of functional bacterial cellulose through ex-situ and in-situ approaches

Bacterial cellulose (BC) has been explored for use in a range of applications including tissue engineering and textiles. BC can be produced from waste streams, but sustainable approaches are needed for functionalisation. To this end, BslA, a B. subtilis biofilm protein was produced recombinantly with and without a cellulose binding module (CBM) and the cell free extract was used to treat BC either ex-situ, through drip coating or in-situ, by incorporating during fermentation. The results showed that ex-situ modified BC increased the hydrophobicity and water contact angle reached 120°. In-situ experiments led to a BC film morphological change and mechanical testing demonstrated that addition of BslA with CBM resulted in a stronger, more elastic material. This study presents a nature inspired approach to functionalise BC using a biofilm hydrophobin, and we demonstrate that recombinant proteins could be effective and sustainable molecules for functionalisation of BC materials

Growth as an Alternative Approach to the Construction of Extra-Terrestrial Habitats

One critical element to space exploration is the ability to construct habitats while minimizing payload mass launched from Earth. To respond to this challenge, we propose the use of fungal bio-composites for ‘growing’ extra-terrestrial structures, directly at the destination, significantly lowering the mass of structural materials transported from Earth and minimizing the need for heavy-duty robotic operations and infrastructure preparations. The construction of human habitation has always involved the use of biologically-produced materials from limestone to wood. Currently, the idea of growth itself, as an alternative construction method, is increasing in interest in architecture and space applications. In parallel with research on insitu resource utilization methods, here we present a new, biological approach for constructing regenerative and adaptive habitats, resilient to extra-terrestrial hazards. Based on the idea of engineered living materials (ELMs), we present the use of mycelium-based composites - which are fire-resistant, insulating, do not outgas, and can be used independently or in conjunction with regolith, enhancing composite ductility - employing the living biological growth in a controlled environment, for the process of material fabrication, assembly and maintenance. Our concept is that, similarly to a seed of a tree, the deployable growing habitation system will contain all the essential information needed to grow the desired structure. The paper will outline the potential and challenges of using bio-composites for space applications and will present how these might be addressed, in order to make this biological approach feasible, providing new, growing materials for design habitats on long-duration missions

Design and modelling of an engineered bacteria-based, pressure-sensitive soil.

In this paper, we describe the first steps in the design of a synthetic biological system based on the use of genetically modified bacteria to detect elevated pressures in soils and respond by cementing soil particles. Such a system might, for example, enable a self- constructed foundation to form in response to load using engineered bacteria which could be seeded and grown in the soils. This process would reduce the need for large-scale excavations and may be the basis for a new generation of self-assembling and responsive bio-based materials. A prototype computational model is presented which integrates experimental data from a pressure sensitive gene within Escherichia coli bacteria with geotechnical models of soil loading and pore water pressure. The results from the integrated model are visualised by mapping expected gene expression values onto the soil volume. We also use our experimental data to design a two component system where one type of bacteria acts as a sensor and signals to another material synthesis bacteria. The simulation demonstrates the potential of computational models which integrate multiple scales from macro stresses in soils to the expression of individual genes to inform new types of design process. The work also illustrates the combination of in silico (silicon based computing) computation with in vivo (in the living) computation