Understanding biomaterial innovation
A Renaissance accompanied by challenges
It’s exciting that we are undergoing an unprecedented renaissance in material innovation. The established pioneers of material innovation during the twentieth century, multinational chemical companies such as Dupont, BASF etc., are no longer the leading or sole sources of material innovation. These huge businesses, which grew off the back of cheap oil and gas, and vast labor forces, in some ways are now on the backfoot, seeking to maintain their standing amidst many new entrants.
In a world where access to capital is easier and more plentiful than ever before, entrepreneurs are able to aggressively challenge the status quo. Material startups bring a speed and agility appealing to VCs and to the industries looking to rapidly move away from petrochemicals.
The ‘Duponts’ of the twenty-first century are likely to emerge from the biotech sector, harnessing biology and renewable inputs, not fossil resources, to power new chemical and material innovation.
The Discovery phase
Yes, we are entering a new era of materials and ingredients, but we are still just at the dawning of this new age.
So while we speak of ‘next-generation’ materials, we’re actually talking about just the 1st generation of, in some cases, entirely new categories of consumer materials.
Arguably we are still in the ‘discovery phase’:
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We are discovering how we can create new materials built with biology not petrochemicals or animals
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We are discovering which technologies make sense and which don’t
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We are discovering what will scale technically and what won’t
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We are discovering what will scale economically and what won’t
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We are discovering what consumers will buy and what they won’t
We haven’t yet even started to experience the unintended consequences of scaling many of these technologies. For more on scaling challenges see Section 3.
The Holy Grail vs
The Minimum Viable Product (MVP)
Much of the challenge around the state of current material innovation is a question of mis-matched expectations rather than technological or team failure.
Brands are used to working with suppliers to advance products, indeed incremental innovation is common to the point of often being taken for granted. However that level of innovation happens within a very narrow band of possibility, built largely on existing chemistries, manufacturing infrastructure and supply chains.
Unsurprisingly, brands view innovation as a linear process where the next version of something is better than the last.
So for brands, investors and supply chain partners, the expectation for a new material might sound something like this:
But for many material innovators that might sound like the Holy Grail! What is described above, they may agree, is a North Star, something to aim for.
Most startups are coming from the other direction. Depending on the level of technological complexity involved, material innovation is usually more iterative and cyclical than linear: design, build, test, learn, repeat.
As private companies with relatively small teams and budgets, compared to industry giants such as BASF, startup innovators need to generate revenue as quickly as possible and are usually seeking to bring to market a minimum viable product (MVP). This is the easiest, fastest solution to a perceived opportunity that will hopefully fulfill a current need with headroom to incrementally improve over time.
Compared with brand expectations, this may sound more like this, in this order:
‘better for humans and the planet, meets, or comes close to meeting, existing material performance and aesthetics in a particular application, potential to meet price parity over time’.
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From Nature to Chemistry to Biology
The reality is most biomaterial innovation today is at the MVP stage.
Our biomaterial innovation journey will be measured in decades like all previous eras of material innovation.
The majority of new material innovation tends to fall into three main categories: dyes, fibers, and alternatives to animal leather or synthetic sheet materials.
Innovation in all these areas faces stiff competition from incumbent technologies which have had the benefit of decades, centuries, even millennia to perfect.
Nature to Chemistry to Biology - using dyes as an example
We moved away from natural dyes during the Industrial Revolution as synthetic colors first became available. Based on coal tar and petrochemicals, able to be manufactured at huge scale, and substantially cheaper to produce, they rapidly took over as dyes of choice during the Twentieth Century. They were vibrant, light stable, resistant to high temperature washing and reliably consistent in terms of quality.
With over 160 years of synthetic chemical development behind us, the dye industry is globally scaled and offers almost any color permutation imaginable at very low cost for a vast array of substrates. These chemicals are high performing and cheap having had the benefit of incremental improvements over many decades.
The emerging bio alternatives to synthetic dyes are mainly derived from living organisms: bacteria, algae, mycelium. This time, rather than exploit the natural world for pigments and dyes; extracting from plants, insects and animals, innovators are turning to sustainable production from organisms engineered to efficiently produce natural colors. These methods typically involve fermentation.
So we’re going back to nature once again, but this time to use the building blocks of nature’s palette without exploiting people and the planet.
Historical sources of dyes from nature:
In some cases, entirely new processes are being deployed, such as Colorifix’s straight to textile dying. Here the color-producing bacteria are fermented and in the same process deposit and fix the dye directly onto fabric. This process, while adding fermentation to the footprint of a dye house, has the advantage of reducing total production steps and therefore uses less water, energy and GHG emissions. The engineered organism used here is a GMO. Most industrial microbial dyes are likely to be GMOs. See section 3.2 for more on GMOs.
Other microbial dyes may be extracted as a powder out of fermentation and then used as a traditional dye-stuff following the same steps as a synthetic chemical.
Near term considerations with biofabricated dyes
Biofabricated dyes are one of the early applications of biotechnology for textiles, however there are still only a handful of startups tackling this challenge. Most of these companies are less than 8 years old, with most still in the early prototyping phase with brands on limited edition products with low volumes. Gradually we are seeing new colors being added to product portfolios, but across the board these companies are focused on scaling their technologies.
With indigo dyed denim one of the biggest market opportunities, it is no surprise many startups are targeting biofabricated indigo as their first product. 2023 should see the first denim brand collaborations with this technology.
Near term considerations with bio fibers
As with alternatives to leather materials, producing new biobased fibers includes radically divergent technologies. The more straightforward approaches are those sourced, for example, from algae.
By comparison, biofabricated fibers have proven to be one of the more challenging biotech developments so far.
Early on, companies such as AMSilk, Bolt Threads and Spiber targeted ‘spider silk’ as a compelling opportunity for biotechnology. The inspiration was ‘what if we could manufacture advanced materials with the high-performing properties found in nature’?. They all designed and engineered microbes to produce spider silk proteins.
for adidas
using Spiber's Brewed Protein™
Beyond engineering a living organism to produce a complex protein (no mean feat), the real challenge lies in transforming the purified protein into a fiber with the desired performance properties and scaling that to achieve a competitive cost.
Spiders have a highly complex ‘spinneret’ that enables them to produce a yarn using multiple types of liquid proteins to create a material of incredible strength and flexibility. The subject of much study, no-one has yet managed to replicate the full spinning mechanism that delivers the unique blend of natural performance features.
However, Spintex in the UK, based on the longstanding work of Professor Fritz Vollrath at the University of Oxford, may have the closest approximation to a biomimetic spinning process for silk fibers.
AMSilk achieved early success with its Biosteel™ yarn, launching a NATO watch strap with Omega in 2019. Notably however, the edges and center section (where the holes are for the metal pin) were woven of a polyamide yarn for greater durability.
The Biosteel™ adidas shoe, which originally premiered at the 2016 Biofabricate summit, has been delayed by years and has yet to reach consumers. AMSilk announced a partnership with Evonik in February 2023 to scale their production of silk proteins.
Bolt Threads showed a prototype Microsilk™ dress with Stella McCartney and a Bestmade hat blended with Rambouillet wool in 2017, but there has been nothing since the prototype adidas tennis dress with Stella in 2019. Bolt has subsequently sidelined their silk protein fibers pivoting to personal care.
Spiber, in Japan, has so far been the most successful in engineering performance protein yarns that have now been featured in various blends and with multiple brand partners including multiple Couture shows with designer Yuima Nakazato since 2019. Their first pilot plant came online in Thailand in 2021 and they are now working with ADM in the USA to scale production of their Brewed Protein™ materials.
Others are taking a more low-tech approach, using macroalgae (kelp/seaweed) as a regenerative feedstock for creating sustainable biobased fibers that can be blended with existing yarns.
Near term considerations with biobased ‘leather alternatives’
Alternatives to leather use a wide variety of technologies. At the most basic these are biobased recipes containing an agricultural or food waste, reduced to shredded fibers or powder, that is mixed with a binder and roller-coated onto a textile which receives a final finish.
There are many variations on this theme. Levels of biocontent in the final materials, and end of life, will also depend on the composition of the textile backer and whether the binder and finish chemistry is petrochemical or biobased.
Near term considerations with mycelium ‘leather alternatives’
The above biobased technologies yield very different materials to those grown with mycelium. The three main approaches to producing mycelium sheet materials are static liquid fermentation, stirred liquid fermentation, or solid state fermentation (no liquid).In all cases heat is used to kill the organism to prevent subsequent growth.
Static liquid fermentation
In static liquid fermentation a sheet of mycelium forms on the surface of the fermentation broth. Once it has achieved desired thickness, it is harvested and might be treated with plasticizers (cross-linked), heat pressed and have an emboss and surface finish applied.
Stirred liquid fermentation
In a stirred bioreactor, clumps of mycelium are grown in an agitated fermentation broth that is then harvested and potentially mixed with a binder and cross-linkers to make a viscous liquid which can feed continuous roll to roll production.This mycelium formulation may be applied to a textile backer and be heat pressed and have an emboss and surface finish applied.
Solid-state fermentation
In solid state fermentation, trays of agricultural or industrial waste, such as hemp hurds, rice hulls or straw (different lignocellulosics dependent on local availability) along with nutrients such as dextrose, are inoculated with mycelium, placed in a chamber at the right temperature and air flow. Typically after two weeks a sheet of ‘ariel’ mycelium can be sliced off the substrate, treated with plasticizers, heat pressed, embossed and finished.
Near term considerations with bacterial cellulose ‘leather alternatives’
At Biofabricate we understand bacterial cellulose as a leather alternative more than anyone. Our founder Suzanne Lee invented this process back in 2002! It is compelling because bacteria can feed on waste streams from, for example, the food industry. This abundant source of nutrients can be low-cost, free, or companies may even get paid to use someone’s waste stream since they are improving the carbon footprint of an industrial partner.
In static tray fermentation, bacteria form a sheet of cellulose on top of the liquid at the air interface. Depending on the thickness of the sheet required, this can take from 5 days to two weeks. It is possible to integrate fibers, yarns, dyes etc in this growth phase making for a particularly efficient process that uses less water and energy and no additional chemistry to bind the material together. The only chemistry required is for the same functionality as for any leather or leather alternative - to stop the material from degrading and for surface finishing.
Wild type bacteria can be used but most innovators will eventually want to genetically engineer the microbe to have even more control over fiber quality, growth rate and so on. As with mycelium, the organism is growing the material (bioassembly) and therefore it goes through a heat or washing process to deactivate the organism in the final material.
As with mycelium and the plant-based leather alternatives, this material is an entirely different composition. It is cellulose. It may be used to mimic the look of leather, but the handfeel, natural aesthetic and performance will be different.
Near term considerations with lab-grown ‘leather alternatives’
Lab-grown ‘leather’ makes most sense as a term when referring to animal tissue grown from mammalian cells, for example fibroblasts or pluripotent stem cells. Even then, the word ‘leather’ probably cannot be applied as it has variously been defined as the ‘tanned hide or skin of an animal’.
However, as tissue-engineering becomes more sophisticated, with time, we can imagine the full structure of animal skin being grown in the lab and that may challenge the current ISO definition*. As a reference, human skin is currently lab-grown for treatment of burn victims.
(early) tissue engineered sample
(early) tissue engineered prototype
(early) tissue engineered samples
At Biofabricate we use ‘lab-grown’ very specifically. Processes to grow sheet materials using mammalian cells require sterile laboratory conditions that meet biosafety level 2 (BSL-2). This will always be the case for the safe handling of those cell types even at scale. Those conditions are required to ensure the cells do not become contaminated.
Tissue-engineering techniques for growing a leather-like material have been borrowed from regenerative medicine. Growing animal tissues in a lab is highly expensive due to the specialized facility, equipment, skilled labor and time it takes to produce. Innovators will no doubt find ways to reduce costs, but there will likely always remain limits to speeding up biological growth.
This is the most complex and costly of all the approaches to producing a leather alternative. Yes, it will probably yield the most accurate mimic of real leather, but the technology still has a long way to go to scale and achieve anything like price parity to a high quality calfskin.
The Innovation Process: A Step-by-Step Guide. 2023. Northeastern Graduate Programs
How Farmers Use Bugs To Make Red Dye For Food And Cosmetics. 2014. Business Insider
A Microscale Synthesis of Mauve. 1998. Journal of Chemical Education. DOI: 10.1021/ed075p769.2
Reconstructing the historical synthesis of mauveine from Perkin and Caro: procedure and details. 2017. Scientific Reports. DOI:10.1038/s41598-017-07239-z
How it Works: The Science of Sustainable Colour. 2023. Colorifix
Evonik partners with AMSilk to manufacture sustainable silk proteins. Evonik. 2023
‘Birth’ Couture Autumn/Winter 2019-2020 - YUIMA NAKAZATO. 2020. Spiber Inc.
Spiber and ADM to partner on US production of Brewed Protein™️ polymers. 2020. Spiber
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