Living building material
Examples include: self-mending biocement,[1] self-replicating concrete replacement,[2] and mycelium-based composites for construction and packaging.
The use of microbiologically induced calcite precipitation (MICP) in concrete was pioneered by Adolphe et al. in 1990, as a method of applying a protective coating to building façades.
[9] In 2007, "Greensulate", a mycelium-based building insulation material was introduced by Ecovative Design, a spin off of research conducted at the Rensselaer Polytechnic Institute.
[16] In 2017 the project expanded into a consortium led by the universities of Cardiff, Cambridge, Bath and Bradford, changing its name to Resilient Materials 4 Life (RM4L) and receiving funding from the Engineering and Physical Sciences Research Council.
[18] The goal of this program is to "develop design tools and methods that enable the engineering of structural features into cellular systems that function as living materials, thereby opening up a new design space for building technology... [and] to validate these new methods through the production of living materials that can reproduce, self-organize, and self-heal.
"[20] In 2020 a research group at the University of Colorado, funded by an ELM grant, published a paper after successfully creating exponentially regenerating concrete.
[2][21][22] Self-replicating concrete is produced using a mixture of sand and hydrogel, which are used as a growth medium for synechococcus bacteria to grow on.
As the bacteria reproduce they spread through the medium, and biomineralize it with calcium carbonate, which is the main contributor to the overall strength and durability of the material.
[25] Biocement is a sand aggregate material produced through the process of microbiologically induced calcite precipitation (MICP).
[28] Microscopic organisms are the key component in the formation of bioconcrete, as they provide the nucleation site for CaCO3 to precipitate on the surface.
[29][failed verification] These factors are essential for microbiologically induced calcite precipitation (MICP), which is the main mechanism in which bioconcrete is formed.
[27][26][29] Other organisms that can be used to induce this process include photosynthesizing microorganisms such as microalgae, cyanobacteria, and sulphate reducing bacteria (SRB) such as Desulfovibrio desulfuricans.
[27] Biocement is able to "self-heal" due to bacteria, calcium lactate, nitrogen, and phosphorus components that are mixed into the material.
[32] This feeding process also consumes oxygen which converts the originally water-soluble calcium lactate into insoluble limestone.
When biocement is used in steel reinforced concrete structures, the microorganisms consume the oxygen thereby increasing corrosion resistance.
Fungal mycelium is incubated with a plant waste product to produce sustainable alternatives mostly for petroleum-based materials.
During this incubation period, mycelium uses essential nutrients such as carbon, minerals, and water from the waste plant product.
[39] Some of the organic substrate components include cotton, wheat grains, rice husks, sorghum fibres, agricultural waste, sawdust, bread particles, banana peel, coffee residue, etc.
[40] Additionally, fungi has an ability to degrade the cellulose component of the plant to make composites in a preferable manner.
There are several bio-sustainable companies Beyond the use of living building materials, the application of microbially induced calcium carbonate precipitation (MICP) has the possibility of helping remove pollutants from wastewater, soil, and the air.
Radionuclei in ground water do not respond to traditional methods of pumping and treating the water, and for heavy metals contaminating soil, the methods of removal include phytoremediation and chemical leaching do work; however, these treatments are expensive, lack longevity in effectiveness, and can destroy the productivity of the soil for future uses.
[43] By using ureolytic bacteria that is capable of CaCO3 precipitation, the pollutants can move into the calc-be structure, thereby removing them from the soil or water.
However, the bacteria analyzed in this study was grown in a highly controlled lab, so real soil environments may not be as ideal.
