Mineralized Matter & Organic Octahedrons

During the lockdown, three businesses did very well: supermarkets, garden centers and DIY shops. Perhaps because these shops reflect three human needs: food, being surrounded by some form of greenery, and the need for shelter. These days, many of us do not grow our own foods anymore, nor do we construct our own houses.

I wondered if not building my own shelter anymore is perhaps making me slightly unhappy? Maybe the need for shelter also comes with an urge to build one myself?

If constructing a shelter is, in some way, part of our DNA, in what forms and shapes can this instinct manifest itself? Perhaps the common ancestor of all animals, the mineralizing sea sponge, that already mineralized its tissue 640 Myrs ago, can re-inspire our building strategies.

I am raised by a feminist mom who would take me to nudist beaches and campings, and I love the feeling of water and wind against my skin. Therefore I would always be a bit confused about nakedness sometimes being okay, and other times uncomfortable, depending on the conditions.

Uncomfort around nakedness is a feature that we share with shellfish and snails. If you think about the shelters humans create, besides our skins, bones and identities (the 5 skins of men, Hundertwasser), you can find two material categories:

The first category is clothing. The word garment, coming from the French word garnir, derived from the Germanic garnish, means 'to cover'. Clothes cover your nakedness and provide portable thermoregulation, often made from organic materials – materials made of carbon-molecules, originally formed by plants or animals, such as silk, wool, cotton, fibers, plastics.

The second category of shelters is the house. The word house comes from the old-English word 'husan', which is probably related to the root of the word 'hide'. Houses, mostly non-portable walled protections against weather influences, indeed protect you from the gaze of other people. These days, buildings and houses are usually made from mineral components, such as cement, which is made from limestone and bricks, made from clay.

Images by Florian Geerken

I became interested in what we can learn from the buildings of other creatures, specifically biomineralizing organisms; mollusks, foraminifera, crustaceans, and vertebrates, forming shells, exoskeletons and bones. Foraminifera are unicellular marine organisms that form a shell of calcite on top of an organic template. Biomineral materials, such as foraminiferal shells, show the remarkable ingenuity of nature's designs: intricate composite materials, combining organic and mineral components, which result in a range of material properties and strong yet flexible building materials.

What if we relearn how to calcify and agglutinate, and become crustaceans, or shell-bearing species? Perhaps we can grow skyscrapers from seawater like corals, or use garments as templates for mineralized exoskeletons. In Waag's Planet B lab at Amsterdam Science Park, I am experimenting with combining the organic, 'clothings' with the mineral, 'buildings' into new hybrid materials and exoskeletons for humans.

What if we place our building materials in the perspective of biogeochemical cycles, expanding the concept of circularity to geological timescales?

Limestone, the main component of cement, actually consists of the microscopic calcite shells of marine biomineralizing unicellular organisms, such as foraminifera and coccolithophores, another type of microscopic creatures forming calcite shells. Over the past 500 Million years, these shells have sunken onto the seafloor and became compacted into rocks and uplifted into mountains. When you know that our houses are build from the 'houses' of microscopic organisms, it's interesting to see what construction methods they use, and if we could perhaps learn from them, and shortcut the geological timescales involved in the formation of limestone, by mimicking the formation of shells?

I am trying out various ways to be a biomineralizing organism, not only uncounsciously, when mineralizing my bones and teeth within my body, but also consciously. My dream is to recreate the 'privileged space', a term coined to describe the space in which organisms such as mollusks form their shells. It's a space secluded from seawater, under tight biological control, where minerals, often calcium carbonates, precipitate on top of an organic template.

During my PhD in biogeochemistry, my colleagues and me did an experiment in Japan, which showed that foraminifera (whose shells are the building blocks of the pyramids in Egypt) secrete their shells at a speed of 0.5 micrometer / hour.

At this speed, it would take a year to form a kitchen-tile of 0.5 cm! So by mimicking this mechanism, I became very frustrated with how long it actually takes to form calcite, and also how difficult it actually is to do this yourself in a simple DIY 'lab'! But I did start to appreciate the effort of all these creatures and the unimaginable stretches of time that go beyond the formation of just a single block of limestone.

A lot of limestone was formed in the Cretaceous, 145 to 66 Million years ago, when it was very warm and sea levels were much higher than today: the many shallow carbonated seas provided excellent habitats for calcifying organisms, resulting in the formation of the White Cliffs of Dover.

Now, we just crush these rocks, all those millions of years of growing shells, and combine it with fly-ash, a coal combustion product, and sand, to create a hard, brittle and not very delicate material: concrete and sort of pour it over the planet.

Cement and plastics, the materials we most widely use to ‘rationally’ design our products and buildings, may not be very smart and elegant, looking at it from a biogeochemical perspective: they clearly disrupt biogeochemical cycles, such as the climate.

Yet our bodies do know how to make smart materials, our bodies know how to biomineralize: our bones are composites of collagen and hydroxyapatite.

How can we move towards more biologically intuitive and less polluting ways of building, within our environments, as well?

These mineral-organic material experiments are inspired by foraminifera, who build their shell by mineralzing an organic template, or by 'glueing' together sand particles collected from the sea floor.

In the left image, you see an 'agglutinating' foraminiferal specimen that my colleague Inge van Dijk placed in a culture dish with glass pearls, that the specimen used to form new chambers.

This inspired me to work with calcite grains harvested from drinking water de-hardening and bioplastics, to form the exoskeleton-like materials shown here.

It was a great pleasure to advise Erco Lai for his KABK Industrial Design graduation project NEO STONE AGE in 2021. Where I obsess over the growth of biominerals, Erco Lai is inspired by 'the way Earth builds' and he reached out to me for some advice. Where I am not a designer, Erco Lai did a great job in his material experiments and design research! He faced some challenges when trying to grow CaCO3 from solutions or by dripping, which remains a slooow proces, but he didn't give up. Erco Lai figured out a way to bind the calcite grains by using a recipe for 'geopolymers'. Where my bioplastic-calcite materials degrade, his methods is much more 'waterproof'. Looking forward to more future collabs with this talented young designer!

Image by Erco Lai.

De Onkruidenier invited me to give a CHALK TALK during their residency at het IJ, at Tolhuistuin.

Images by Tim Hillege.

In my attempt to build like a shell, like a calcifier, I also tried to grow calcite on top of organic materials, yet this proved challenging due to the slow growth of the calcite mineral.

Here you see me and Ronald de Onkruidenier trying to grow calcite together, using CO2 from our breath as a source of carbon.

Image from Parool article about the Sweet Sweat installation of De Onkruidenier at Tolhuistuin.

Photo by Florian Geerken

The Material Experiments are part of Build like a Shell, supported by the AFK (Amsterdam Fund for the Arts) and Mineral Matters & Organic Octahedrons, supported by the Creative Industries fund NL (Stimuleringsfonds). Both projects were kindly supported by Aquaminerals.