Olivine

Make Like a Leaf

Photosynthesis is the oldest growth system on earth and the most powerful ‘Net-Negative’ technology we know. Having transformed a once hyper-hostile planet into a blue-green earth, it has proven its potential to increase the planet’s capacity to regenerate the atmosphere and re-balance earths ecosystems.

Make Like a Leaf harnesses photosynthesis as a tool for design by turning to its inventor: Cyanobacteria. The material is fabricated through a process called photosynthetic biomineralisation. The substrate minerals are embedded with cyanobacteria that capture carbon from the atmosphere and transform it into a binding mineral. In this way, the carbon is not only captured, but also safely sequestered. This process is akin to harnessing photosynthesis as nature’s 3-d printer: a solar-powered process that solely relies on the abundant resources of sunlight, CO2, and water, and from it fabricates a product.

This research focuses specifically on maintaining this material’s vitality through hydrogel development, nutrient access, and light transmission, while optimising its carbon-capturing capability. The substrates selected to bind are olivine and calcite. Olivine is one of the most abundant minerals on Earth, and is a primary mineral in the Earth’s mantle. When exposed to rainwater, a chemical reaction occurs that produces dissolved ions, including magnesium, iron, and silica. These ions can then react with carbon dioxide in the atmosphere to form solid carbonate minerals. Cyanobacteria can grow on the surface of the mineral and capture carbon through photosynthesis. Combining this with the weathering process of the mineral itself has the potential to significantly increase the carbon capture of the material. Calcite is an abundant natural mineral with a high refractive index. Incorporating optic calcite into the material helps to scatter light and allow for more uniform distribution throughout the growth medium. Its surface chemistry also includes important nutrients for cyanobacterial growth.

The material is capable of regeneration from one parent generation in response to physical switches such as temperature and humidity. High humidity and slightly heightened temperature rekindle the metabolic activity of the material, allowing for components to be brought onto the next generation. This also means a material sample is able to go dormant for a period of time and then be “turned on” again using these physical switches.

This research is in response to problems within the construction industry - one of the least sustainable industries in the world. Our planet simply cannot support its current level of resource consumption and CO2 emission; the sector must urgently decarbonise. Along with the negative impacts on global primary productivity, the building industry has also contributed to a perceptive separation between human and nature. A brick wall acts as a non-responsive and non-permeable barrier that blocks the human from interaction with the natural elements. It serves as protection, but also suffocation and disconnection from what is now distinctly inside and outside. This reinforces the idea of humans as central agents, with the material world as a passive backdrop.

A large part of this research has been into exploring the ways in which the development of new material could contribute to the re-thinking of architecture: away from the designing of bricks and towards the design of atmospheres, interacting with and connecting the human to the spheres of the earth. Designing with living material introduces the relation of architecture to a plant: it requires care, awareness of geology, moisture, and the flow of seasons. Connection to place is crucial for its ability to grow and thrive. The material challenges a separation between a building and a leaf: both emerging from an assemblage of materials and the natural systems that direct their creation.

Making process

Cyanobacteria are grown and scaled up in the lab, and are then combined with hydrogel, NaHCO3, and CaCl2 · 2H2O to induce the biomineralisation. The substrate materials: calcite and olivine, are submerged in the hydrogel and act as a scaffold for the cyanobacteria to grow around. The sample is exposed to air and light and within 48 hours will harden to a stone-like consistency.

Text submitted by the maker and edited by the Future Materials Bank. For information about reproducing (a part of) this text, please contact the maker.