In 1997 the American biologist Janine Benyus publishes Biomimicry: Innovation Inspired by Nature, the book that gives a name to a practice as old as architecture itself: looking at how nature solves a problem before inventing a technological solution from scratch. The term has enjoyed enormous fortune, but it actually covers three very different approaches, often confused as if they were the same thing. Telling them apart is the most useful way to understand why the innovative materials in this chapter — mycelium, sand-cementing bacteria, biocomposites that biodegrade — are not the same story at all as the historical precedents they are often compared to.
Biomorphism: imitating form
The most superficial level — not in the sense of least valid, but most direct — is biomorphism: borrowing a natural form because it is aesthetically or structurally effective, without necessarily understanding or replicating how it works internally. Antoni Gaudí, at the end of the nineteenth century, builds hanging funicular models — networks of cords and weights that, inverted, naturally trace the shape of an arch in pure compression — to design the crypt of the Colònia Güell and the Sagrada Família. He is not studying biology in the strict sense, but is letting physics — the same physics that governs the growth of a tree trunk or the shape of a bone — suggest the geometry to him. It is a method, not a literal imitation: the resulting form resembles an organic structure because it obeys the same laws, not because it copies a specific organism.
Buckminster Fuller takes this logic to a more explicit level with his geodesic domes, starting in the 1940s: the triangulated structure that distributes load across a three-dimensional lattice is the same geometry found in the shells of certain microscopic marine organisms, radiolarians, discovered and drawn by Ernst Haeckel back in the nineteenth century. Fuller was not copying radiolarians — he arrived there through engineering — but the coincidence was noted and used rhetorically for years as proof that "nature had already invented" the most efficient forms.
Functional biomimicry: imitating process
The second, more ambitious level does not copy form but mechanism. The single most cited example — to the point of becoming almost a cliché of the field — is the Eastgate Centre in Harare, Zimbabwe, designed by architect Mick Pearce and completed in 1996. The building, a shopping centre and office complex, had to operate without a conventional mechanical air-conditioning system in a climate with large daily temperature swings. Pearce drew on the passive ventilation system of termite mounds: African termites build earth mounds several metres tall, threaded through with a network of ducts that, exploiting the temperature difference between the inner nest and the outside, generate a convective flow able to keep the colony at a nearly constant temperature despite outdoor swings of thirty degrees or more between day and night.
The Eastgate Centre replicates the principle, not the form: ventilation stacks, exposed thermal concrete mass that stores heat by day and releases it at night, low-power fans that assist the natural convective flow instead of replacing it. The result claimed by the designers is an energy consumption for climate control of around 10% of a comparable building with a conventional mechanical system in the same climate. It is a conceptual leap from Gaudí's biomorphism: here it is not a geometry being imitated, but a functional strategy — passive heat management through mass and ducts — translated into entirely conventional materials and techniques (concrete, brick, air ducts).
Frei Otto, in the same period in which Fuller was working on geodesic domes, applies an analogous principle to tensile structures: soap films stretched across a frame spontaneously assume the minimal-area surface possible for that boundary — a physical principle, not strictly a biological one, but one Otto studies alongside comparable biological forms (spiderwebs, cell membranes) for the German pavilion at Expo 67 in Montréal and for the Munich Olympic stadium of 1972. Here too: not literal imitation, but understanding and translating a principle that nature and physics share.
Biofabrication: nature as producer, not as model
The third level is the one to which the materials in this chapter belong, and it is categorically different from the first two. Here nothing is imitated any more: the production of the material itself is delegated to a living organism. Hy-Fi's mycelium does not "resemble" something natural — it is, literally, a fungus growing. The Sporosarcina pasteurii bacteria in MICP bio-bricks do not inspire an analogous industrial process: they are the real chemical agent that cements the sand. It is the difference between painting a tree and planting one, and it coincides historically with a precise technological leap: the ability, developed above all from the 2000s onward, to control the growth of organisms in the lab (fungi, bacteria, in some cases even silkworms — see the in-depth piece on Neri Oxman in this same section) with a precision sufficient for repeatable construction use.
This third level raises questions the first two never had to: who owns the patent on a bacterial strain engineered to produce calcite more efficiently? How does a regulatory body certify a material whose performance depends on the vitality of a microorganism rather than on a fixed, repeatable chemical composition? That is the subject taken up in the regulation piece in this same section. Gaudí's biomorphism and Pearce's functional biomimicry never had to answer these questions, because the final material — stone, concrete, steel — remained a conventional, industrially produced material, simply organised according to a nature-inspired principle.
Why the distinction matters today
Understanding this scale — from form, to process, to producing organism — helps avoid dismissing innovative materials as "just another biomimetic fad" lumped in with geodesic domes or the termite mounds of Harare. They are the consequence of a categorical leap: the shift from nature as a source of inspiration to nature as a tool of direct production. It is a leap that brings enormous advantages — often-negative carbon footprints, very low-energy processes compared with firing or conventional chemical synthesis — and equally new problems, which the rest of this chapter tries to describe without sugarcoating.