Nacre i
Project Sea_Chell | Stimuleringsfonds Architecture Fund | 2021-2022
Nacre I was an exploration into the scaled production of Nacre, also known as mother of pearl, as an interdisciplinary research towards a meaningful bio-integrated architectural installation.
As a natural material produced primarily by mollusks, Nacre is known for having impressive mechanical properties, structural irridscence, providing both utility and aeshteic value to humanity for millenia. Mollusks, through their evolution, have found ways to produce nano-scaled, three dimensional brick-and-mortar strucures; carfully laid tesselations of calcium carbonate, aragonite, and other calcium minerals found in marine environments, and biopolymer-protein complexs of chitosan, fibroin, and lusterin acting as mortar and an anti-microbial.
When light passes through these nano-structures, we witness the emergence of structural color in its many forms and colors, known as ‘mother of pearl.’ Mechanically, these same structures are responsible for producing impact resistance, as this matrix of hard crystal platelet and soft biopolymer enables the effective dissipation of energy across its surface area before an event of fracture, under mechanical pressueres and impact.
Artistically and architecturally, we saught to apply these biomimetic structural properties directly to architecture, imagining large scale paneling and organic architecture that would behave with the same dexterity as a mollusks shell. Further, envisaging bio-mimetic architecture in an embodied form, looking to nudge bio-integrated design away from speculation in architecture and design spaces.
This 12 month research explored an array of methodologies to produce no-fire, nacerous bioceramic tiling, both through means of mechanical and cellular assembly, arriving at a formulation that could be scaled further given adequate capital contribution.
the Cellular weaving of a sea shell
Over millions of years, mollusks have developed a specialized epithelial layer, called the mantle, that elegantly deposits combinations of organic mortar with mineral platelets to produce their architectually rigid shells. Like a futuristic bioprinter, the mantle produces the shell layer-by-layer, controlling precise amounts of mortar componants and aragonite aggrigate to produce a gradient from hard and rigid to smooth and optically iridescent. These complex shell architectures both protect the creature from predation from other animals, as well as provide a smooth anti-microbial surface that protects them from potential infection from marine-borne parasites and micro-organisms.
In contrast to this elegantly evolved biological machinery, most human-made nacre-like composites require complex processes typically involving toxic chemicals, extreme temperatures, and/or high pressures, typically yielding low amounts of material samples. As this exploration was oriented towards an architectural installation scale, we also faced a need for the careful consideration of production requirements in terms of material toxicity and financial limitations.
Addressing both of these concerns, we saught to closely reproduce the material composition of naturally produced nacre, combining the building blocks of wild-type nacre: chitin, silk protein, and a calcium phosphate called brushite in exchange for aragonite. In so doing, developing a material production process requiring low amounts of heat, below 60 degrees celcius, and small amount of pressure to produce a versitile, fully biocompatible nacre biocermic.
The image to the right shows the research and developmet process from the production of thin chitin films, then incorporating larger to progressivly smaller particulates of brushite to produce a chitin-brushite composite. The final three samples were produced after arriving at a protocol to molecularly assemble colloidial suspension films - resulting in a fine interwoven calcium crystal lattuce structure held together with our organic biopolymer mortar.
Molecular bricks
& Mortar
The protocol developed during the R&D phases of this project was replicated to produce a number of samples for Scanning Electron Microscopy (SEM) analysis to inspect and refine the nano- and micro-scaled brick and mortar structures, tweaking aspects of our production protocol to ensure that the platelets would aline in a formation closely resembling naturally produced nacre. Machining these samples required carbide tipped tools to create visible material cross sections for SEM imaging. Imaging was carried out at both Bolton College and the University of Manchester, with assistance from Alex Bennett.
The images on the left and right correspond do one another, where the large images are at a cross section scale of 40 micron (um) to 200um, the smaller images range from 10um to 20um. These micro scale images show that what resulted from our bottom-up production method was more akin to a molecular bio-concrete than the elegant brick and mortar structure of naturally occuring nacre. Nevertheless, sections of these materials showed close comparisons to our goal by displaying lineraly aligned crystal platelets interlocked with organic mortars, producing beautiful images reminiscent of cliffs, large geological formations, sharp caves, and alien like landscapes.
In all instances, the material properties were tremedous, surviving 72h water submersion tests, direct flame tests, and became breakable only after aborbing ambiant skin oils after months of handling and display; proving while architectural inelegant, these materials provide a tremendous amount of dexterity and utility to design applications.
from micro- to macro architecture
The final stages of this interdisciplinary research project used midjourney to explore pavilion architectures as a visual output to this more abstract, scientific research. These outputs were creatively prompted and iterated until we arrived at a selection reminiscent of bone and shell architecture, highlighting the material’s shell origins, while choosing bone and marrow motifs to visually signal the molecular exchange of aragonite for brushite - which is a common calcium componant of bone architecture but not commonly found in marine environments. As a design language, we found these emergent patterns poetic repersentations of these molecular inteventions.
Imagining how to produce organically curved panels and bone-like structural framing, large sheets of composite films would be cast and cut by laser to fit milled or casted aluminum molds prior to pressing under the right heat and pressures, provided by industrial scale heated hydraulic presses. Once set, the outer shell componants would be repressed at a higher heat to sear the outer layers to make them more resistant to weathering before sanding any heating artifacts from the panel surfaces.
Secondary, aeshteic panels would be produced in a similar method, with details drilled out with carbide, multi-axis milling tools; providing combinations of marrow-like caveties or ridge like sinue connections dependant on the final design.
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