Waterfront Mushi

The aims and objectives of this research were to: (1) materialise the concept of a mycelium based biocomposite artificial wetland composed of interlocking modules (2) Test the prototype in a real-world environment and collect data.

To achieve the objective, the following were produced, tested, and analysed in a lab environment to inform the final outcome:

Material composition and fabrication:
Different fungi species were tested as their network structure varies in strength, density, and growth rate between the various types. Different organic waste substrates were tested. While mycelium can colonise most cellulose-based organic waste, the geometries and granularity of the substrate impact the strength of the mycelium material (e.g. fibrous materials apply better than particles).

Growing conditions: The incubating environment impacts the outcome of a bio-fabrication process. Optimal temperature, moisture levels were tested, as the ability to maintain an averaged moisture distribution and access to air across the material within a module is important for scalability.

Buoyancy: The desired submergence level of the wetland was calculated using mycelium-material density, soil density, plant weight, the mass of internal timber support, potential water absorption and impact on mycelium structure.

Structural capacity: Various prototypes were created and tested in Swinburne’s structural lab.

The design outcome was 3x800mm diameter triangular-shaped modules. The modules are made with a bio-composite material composed of mycelium and sawdust. While mycelium can colonise and digest a range of cellulose materials, sawdust was used as the substrate for its linear and fibrous forms, which when bound by mycelium results in greater material strength. The mycelium material is set within specially designed moulds that expand to form the structure of the floating wetland. Above the surface, native wetland plants were grown within the compound to create a habitat for insects and birds while the roots penetrate the base for water purification.

Artificial wetlands have been proven to have a positive impact on improving ecological systems by harbouring plants that purify wastewater whilst creating habitats for wildlife. However, typical floating wetlands are made of a plastic-based substructure that degrades over time. At the end of its life, it is difficult to recycle the waste plastics. Mushi provided a tangible alternative that is completely organic and biodegradable.

In addition, this prototype embraces the concept of circular economy mimicking the material cycles in a natural system. The bio-composite used to construct the wetland is grown using a waste product/by-product from another industry process. The waste materials are upcycled into a new product with minimum energy input. The biodegradability of the organic matter means that the wetland end of product life can be returned to the soil and transformed into nutrients and fed back to the natural ecosystem.

While mycelium-based product development has emerged in recent years, its durability has never been tested in an open natural environment while submerged in water.

An applied research method was employed to investigate the different aspects of the material characteristics and structural capacity of mycelium composite, leading to the design and fabrication of a functional artificial wetland using biomaterial.

As a preliminary result, the design team has proven the viability of creating large-scale mycelium masses that functions as artificial wetlands. To the authors' knowledge, the final product is the world’s first wetland made completely out of biomaterials, trialled, and tested. During the 6-month trial period at the Royal Botanical Gardens, the plants housed on the wetland has grown significantly. The conclusion of the trial will lead to a novel understanding and new findings of using mycelium for functional products beyond furniture scale and in an outdoor environment.

In addition, the successful delivery of this prototype also demonstrates a tangible production method, embracing the concepts of a circular economy in contrast to the current linear ‘take-make-waste' linear economy in our society. The manufacturing of this bio-composite artificial wetland not only requires low-energy input but upcycles the wastes in our existing production system into a valuable product that solves a real-world issue – cleaning up our waterways.

Artificial wetlands are proven to have a positive impact on our environment. This design further reduced the environmental impact of the material and production of the typical wetlands and provides a completely organic solution, making contribution to the sustainability of our contemporary landscape.

Furthermore, this mycelium wetland is based on ongoing research into the application of mycelium composite in design and architecture. The background research has led to multiple exhibitions and media coverage such as the Future Prototyping Exhibition, ARUP Research Review, Annual Design Research Conference, Open House Melbourne, etc.
The research was featured in the television channel 10 show ‘Scope’ which promotes science to young Australians, contributing positively to society beyond the academic circle.

Once the testing is complete and data collected, the current project will be documented and published on scholarly platforms such as conferences and journals.

Commercially, this prototype deployment was an ambitious step towards a commercially viable solution. The authors are in the process of transitioning to commercial application with the economics of the solution looking promising at scale. The Mycelium structural matrix can be formed through the mycelium consuming waste materials such as sawdust. It can be incubated effectively in shipping containers with suitable thermal conditions.

Since the exhibition of the mycelium wetland, the research has triggered interest in fields beyond the design community and covered widely in articles by organisations such as intengine, Australian Water Association and Sustainability matters triggering more interest in sustainable production methods and opportunities.

The successful delivery of this prototype also demonstrates a tangible production method, embracing the concepts of a circular economy in contrast to the current linear ‘take-make-waste' linear economy in our society.

Firstly, cellulose-based materials are the primary substrate for mycelium composite. In the previous research conducted at Swinburne, the project team successfully grew the mycelium composite using a range of organic waste such as coffee grounds, corn husks, rice husks, coconut husks, fruit pulp, hemp sawdust and cardboard. Therefore, this characteristic allows the mycelium based composite material to be grown by upcycling agricultural and industrial waste. In this instance, the artificial wetlands were developed using sawdust, a type of industrial waste, as their primary cellulose fibre.

Secondly, in contrast to most traditional manufacturing processes, making the artificial wetland requires minimal energy input. The organic wetland was grown rather than fabricated, and the moulds were designed to be reusable. Furthermore, the wetland was grown in an insulated environment at room temperature without additional heating and cooling.

Finally, when the wetlands reach their product end life, they are 100% biodegradable due to their organic nature. Alternatively, the wetland can be shredded and used again for growing other mycelium composite-based products.