Bioreactors as Additive Manufacturing Environments

Abstract

This article discusses the evolving use of bioreactors, beyond traditional life sciences and bioengineering, in fields such as architecture, fashion, and product design. It explores the role of bioreactors in additive fabrication, highlighting their distinct characteristics compared with conventional digital manufacturing. The discussion is centered on the differences in materializing biologically-active (living) versus biologically-passive, or biologically-derived (nonliving) matter in which ingredients require closed-loop fabrication environments that differ from traditional additive manufacturing tools. Two novel biofabrication platforms, Microbial Design Studio and B | reactor are presented as examples with case studies demonstrating their use in various manufacturing workflows with live cells. The article emphasizes the unique capabilities of bioreactors in engaging with living matter and facilitating complex interactions between biological, algorithmic, and mechanical systems in additive manufacturing.

Introduction

Bioreactors, fermenters, and incubators serve as controlled environments for the cultivation of biological organisms, cells, or tissues. These equipment play a foundational role in the fields of life sciences and bioengineering. However, in recent years, their applications have expanded beyond these domains, finding relevance in architecture, fashion, and product design research. This shift is attributed to a growing interest among designers in cultivating microorganisms, cells, and engaging with biobased processes to create materials and end products.^1,2

In this article, we discuss the role of bioreactors as additive fabrication environments and explore their difference from conventional digital manufacturing workflows. Bioreactors use biological processes such as protein synthesis, cellular aggregation, and self-assembly. Here, cells assemble, disassemble, and remediate, either creating new materials or transforming existing ones, shaping their function, aesthetics, and agency. We examine how these environments enable various aspects of working with living matter, emphasizing two specific areas where biological fabrication necessitates a departure from traditional digital fabrication methods:

• 1.Differences in the realization of living versus nonliving matter.
• 2.The contrast between fabrication “environments” and “tools” concerning their role in materializing biobased designs.

We illustrate these concepts within the context of two novel biofabrication platforms, Microbial Design Studio³ and B | reactor, developed between 2018 and 2022 to support additive manufacturing workflows. These platforms were developed at Biorealize Inc., where the author was the co-founder and chief technology and design officer, overseeing the development of the technologies. The article will discuss the technical capabilities of both platforms as examples of biomanufacturing environments and will highlight two case studies developed with B | reactor to demonstrate multimodal (liquid and solid states) culturing processes to create raw ingredients, materials, or end products.

Materializing Living Matter

Biobased additive manufacturing has emerged as a rapidly growing field, leaving a profound impact on diverse areas such as therapeutics,⁴ food research,⁵ and material design.⁶ This dynamic field continues to evolve, drawing contributions from the realms of life sciences, engineering, and design, resulting in a multitude of innovative workflows. Within this context, designers are pushing the boundaries by prototyping unique fabrics made from bacterial cellulose, experimenting with textiles dyed using microbially-derived pigments, and even cultivating biobased cement, among numerous other groundbreaking designs.

While these workflows can be categorized based on their application areas or their utilization of various manufacturing techniques and equipment, adopting a lens focused on ingredient design provides a distinct perspective. Biological matter exhibits diverse chemical and biological attributes, contributing unique affordances throughout the manufacturing process. Designers combine the inherent agency of biological elements with the functionalities of the fabrication equipment, orchestrating the assembly, catalysis, and fusion of biological matter with complementary ingredients such as fillers, backings, scaffolds, and carrier substances to ultimately produce end products.

To foreground these differences, we propose a three-tier classification system:

• 1.Biologically-passive ingredients.
• 2.Biologically-derived ingredients.
• 3.Biologically-active ingredients.

All three categories of ingredients seamlessly integrate into 2D or 3D digital fabrication paradigms, including fusion deposition modeling, selective laser sintering, liquid/paste deposition, printing, direct ink writing, binder-jetting, or extrusion, within novel application domains.⁷ However, it is important to recognize that the role of cells, cultures, and tissues in each fabrication method varies significantly based on their respective agency and characteristics (Fig. 1).

FIG. 1.

Relationship among biologically-active, -passive, and -derived ingredients.

Biologically-passive ingredients

Biologically-passive ingredients represent a category of nonliving organic matter that occur as by-products or remains of natural living processes. They inherently possess inert qualities and constitute the most abundant source of raw materials available for upcycling into novel processes. An illustrative example involves the incorporation of shredded cellulose fibers or wood flour into thermoplastic polymer matrices at varying proportions, ultimately transforming them into 3D printing filaments, as demonstrated by Tao et al.⁸

For instance, algae blooms can be harvested and processed to produce pellets and filaments used in foam manufacturing.⁹ Another example involves chitin, sourced from shrimps, crabs, and shellfish. Through a series of transformative steps, chitin can be demineralized and deacetylated to yield chitosan, a versatile material that can be processed into liquid solutions or gels suitable for extrusion-based manufacturing.¹⁰ This category inherently consists of organic matter that is not intentionally cultivated but rather repurposed into a new material through the fabrication process.

Biologically-derived ingredients

Biologically-derived or -sourced ingredients originate from living organisms after they go through a design process (e.g., genetic modification, selective breeding, fermentation, farming, etc). The organisms also undergo a transformation process to render them inert or biologically-passive. A variety of biobased fabrication methods rely on the cultivation, growth, or harvesting of substantial quantities of living matter to generate the foundational raw materials essential for additive manufacturing processes.

Spirulina serves as an example of living matter cultivated to yield plastic resins. Silkworms are another valuable resource, where their harvest results in the extraction of essential proteins.¹¹ Similarly, genetically-modified organisms are used to synthesize proteins as end products (i.e., therapeutic proteins such as insulin) or to source ingredients that become part of new materials such as chromaproteins, or enzymes that have many industrial applications.

These biologically-derived ingredients primarily exert their influence through chemical agency, engaging in interactions with other substances to form chemical bonds, undergo processes such as polymerization or cross-linking, or change states to create distinct surfaces and structures. In essence, they play a pivotal role in the chemical aspects of the manufacturing process, contributing to the formation and modification of materials with diverse properties and applications.

Biologically-active ingredients

Biologically-active ingredients, on the other hand, represent living matter that remain alive during the manufacturing process. These cells maintain their biological agency during and sometimes even after the manufacturing process, persisting as living end products. Examples include microorganisms such as algae, yeast, bacteria, mycelium, or animal cells propagated from seed cultures. They are incorporated into bioinks, gels, or other carrier substances, facilitating their dispensation onto surfaces or scaffolds.¹² These biologically-active ingredients find application in various contexts, including functionalizing surfaces as proxy indicators or biosensors.^13,14 They can also be employed as biological barcodes for tracking the provenance of objects.¹⁵ Moreover, mycelium slurries, when deposited in 3D, have the capacity to grow, bind, and fuse, resulting in the creation of solid structures.

While the fabrication process often suspends or terminates the biological activity of these ingredients to prevent further growth, maintaining them alive can introduce time-variant behaviors, such as binding, assembly, or decomposition, as cells retain their vitality.¹⁶

These examples highlight the diverse types and degrees of agency exhibited by biological matter. The materialization process can encompass purely chemical transformations, start as biological, evolve into a chemical phase, or remain biological throughout all stages. These distinctions, unfortunately, are often underappreciated in design, engineering, and scientific literature, where living matter is frequently relegated to the status of an “ingredient” or “material.”

The term “engineered living materials” provides a finer distinction, referring to materials that involve living processes, including growth, sensing, communication, translocation, motility, self-assembly, colonization, biodegradation, decomposition, and more.¹⁷

To further clarify this concept, we propose a nuanced differentiation between living organisms and materials or ingredients. Living organisms are inherent participants that can become “ingredients” or “materials” when integrated into a manufacturing process, effectively “materialized” based on their biochemical agency through specific human intentions.

Finally, it’s essential to consider where the materialization process occurs. Biologically-active ingredients necessitate the use of bioreactors or bioprinters that provide the right growth conditions. The tools and equipment used to transform inert materials, however, do not necessarily constitute environments designed for the cultivation and proliferation of living matter. A fabrication studio differs from a biology lab, and a 3D printer is distinct from a bioreactor. While additive manufacturing is not synonymous with farming or fermentation, there are now innovative ways to bridge these spaces, facilitating the realization of biobased designs.

Additive Manufacturing Environments

Designers have utilized biology for millennia to create materials and end products, such as cotton, wood, plant-based dyes, and leather. Today, biobased additive manufacturing processes build on this history by converting microorganisms, cells, and biological processes into materials. However, there’s a distinction between how designs are implemented and realized based on the ingredients’ agency and the environments where these processes occur.

Historically, the division can be attributed to logistics. Incorporating microorganisms or live cells into fabrication processes presents challenges. Tools for inert materials differ from those for biological matter. Organisms require specialized conditions such as nutrients, heat, gas exchange, and sterility to grow into designs. These conditions are maintained in controlled environments such as bioreactors, incubators, and growth chambers, separating the places where biological ingredients are produced and where they are assembled into designs. For example, dispensing live cells with a CNC-based liquid dispensing platforms or bioprinters requires prior cultivation of cells in biosafety level labs with specialized tools. Architecture and design school fabrication labs are typically designed for nonbiological materials and lack infrastructure for live cultures. Biology labs are not equipped for fabrication equipment. The separation introduces additional workflows to bring raw materials, cultures, media, and equipment together. This also challenges pedagogy, training, and adoption of biobased additive manufacturing practices due to cost and disciplinary separation.^18,19

The distinction between fabrication tools and growth environments becomes evident in how they manifest designs. While bioreactors or incubators facilitate the growth, fabrication, and self-assembly of cells into designs, they are not commonly referred to as additive manufacturing platforms. These environments are equipped with control algorithms, sensors, and actuators that execute specific environmental recipes, adjusting conditions such as temperature, liquid circulation, or gas exchange to create ideal surroundings for microorganisms to propagate or reproduce.

The fundamental contrast lies in their control strategies. Fabrication tools, such as a ceramic 3D printer, typically follow fixed routines or algorithms to carry out processes, such as melting, fusing, or dispensing, irrespective of the material loaded into their syringe. They deposit the ingredient based on predetermined coordinates in a 3D plane.

In contrast, growth environments work with the inherent logic of microorganisms to facilitate their agency. These environments operate with feedback loops that respond to the demands of living processes, dynamically adjusting conditions for the different stages of the growth. They adjust temperature, deliver nutrients when needed, ventilate to remove excess carbon dioxide (CO₂), or irrigate to create more space.

Within these growth environments, fabrication occurs through accumulation. Cells reproduce and aggregate, forming biological entities such as cultures, colonies, tissues, films, or cellular networks.

Ceramics printers can also be augmented to deposit live cultures such as inoculated mycelium slurry onto a surface to create solid objects and furniture, while mycelial cells continue growing and transforming the designs.²⁰ Printers that deposit biological matter are often referred to as bioprinters. Live cells in suspension are deposited via mechanical or air pressure onto solids, surfaces, or scaffolds where they can continue to biologically functionalize the designs.²¹

The lines between fabrication tools and growth environments blur in platforms that integrate both the logic of living and digital systems. For instance, the microbial 3D printer showcases the hybrid of a bioreactor and a bioprinter. The platform creates optimal conditions for growing bacterial cellulose into pellicles. It incorporates a fermentation vessel, a vision-based sensing and light-projection system, nutrient supply infrastructure, and software to optimize growth conditions. In addition, it enables coculturing of bacterial cellulose with other engineered cells, enhancing the capabilities of the pellets.²²

As another typology of growth environment, microbial fuel cells provide the conditions to harvest energy from a consortium of bacteria. These systems are designed as electrical circuits that harvest the electrons produced by bacteria as they decompose organic matter from soil, wastewater, or other sources. As bacteria grow and form biofilms in the electrodes of the circuit, the released electrical energy gets accumulated in batteries, used directly, and spent in processing other downstream design applications. These systems are equipped with feedback loops that adapt to the available electricity and its allocation for various applications until it can be regenerated.²³

Algae photoreactors also utilize feedback loops to control the light, temperature, and pH inside liquid vessels to optimize algae production. Certain photobioreactor architectures can be equipped with additional sensors to monitor the physiological state of the microalgae inline by recording the chlorophyll fluorescence parameters exhibited by the organisms.²⁴ Here, a fluorescence sensor is used to tune the amount of UV-B light exposure the cells need for optimal calculation. Both over- and underexposure to the light causes suboptimal performance, so the photoreactor used its feedback loop to design a light exposure recipe for the cells. Algae cells have commercial applications both as end products (dried and converted into food supplements), ingredients for making biobased urethanes²⁵ or as pigments.²⁶

A summary comparison between the bioreactor (environment), bioprinter (tool), and 3D printer (tool) can be seen in Figure 2. In a traditional workflow, cells that are the outputs of a bioreactor can become ingredients of a bioink that gets dispensed through a bioprinter. However, while these technologies often serve as distinct categories, there are integrated design platforms that can combine different aspects of growth environments and tools in one embodiment. Hybrid platforms incorporate feedback loops that are needed to grow the cells in culturing media and tune material properties through additional physical or chemical manipulation with printing heads. While hybridization provides greater control over customizing material properties for a specific biological process, it makes the tool highly specialized and not versatile to grow multiple organisms or cell types.

FIG. 2.

A comparison of three fabrication paradigms with respect to ingredients and outputs.

Bioreactors as Design Studios

Biorealize’s Microbial Design Studio offers a more-general feedback-based incubation platform, which can do both inline sensing and in situ modification of cells. The platform supports multiple workflows. It can engineer cells by introducing foreign DNA, make end products, for example, biomolecules, with them, or grow cells that can materialize into upstream design processes (Fig. 3). It is equipped with an electroporation unit, which can genetically transform cells with high voltage (Fig. 4).²⁷ Cells delivered via standardized electroporation vessels can be serially transformed and subsequently transferred into a cultivation area, where they can be cultured in separate syringes. The rotational platform can heat, agitate, and monitor the optical density of the cells with a spectrophotometer. Once cells complete their growth cycle, they are transitioned to a postprocessing station where they undergo spinning through a centrifuge. This fabrication framework operates both as a bioreactor and a liquid handling system as it can transfer ingredients across vessels with motorized 30 mL syringes.

FIG. 3.

Microbial Design Studio is a countertop biofabrication platform that can genetically modify, culture, and process microorganisms. It streamlines the process of designing microorganisms and can be used for running concurrent experiments under different conditions.

FIG. 4.

Microbial Design Studio patent drawing showing the overall layout of the transformation, incubation, analytics, purification sections of the platform.

In addition to utilizing sensor-based feedback loops to maintain precise environmental conditions, the platform can execute advanced recipes aligned with specific design objectives. For instance, a growth recipe can be configured to conduct a combinatorial experiment involving the transformation of a microorganism with eight distinct plasmids, each introducing genetic variations. The platform can track and assess the performance of each variant, ultimately selecting the design that exhibits optimal characteristics. Design experiments can be distributed across multiple Microbial Design Studios to create a larger high-throughput architecture. Learnings from each experiment can be retained and used in later recipes. Microbial Design Studio was tested for a variety of biological designs—Genetically-modified bacteria, dyes, and biosensors, which are incorporated into bioinks or used as end products for apparel design.

Multimodal culturing environments

The growth environments discussed before are mainly liquid-based systems. Bioreactors for bacteria, algae, and yeast are often used for scaling up designs. However, an important part of biological prototyping happens in solid state. Cells are cultured in petri dishes or plates and then selected for liquid culturing. Multimodal culturing environments that can support both solid and liquid fermentation reduces the need for biology labs further and offer more advanced feedback loops between different stages of the fabrication process.

B | reactor provides a portable, all-in-one liquid and solid fermentation platform that allows designers to grow organisms next to their sewing machines, 2D and 3D printers, or electronics workbench (see Fig. 5). This platform can culture different strains of bacteria, yeast, algae, or mycelium in liquid state for environmental conditions optimized temperature, light, gas exchange, or mechanical agitation. The same organisms can also be cultured in solid state, in which their conditions are optimized for humidity, moisture retention, airflow, aerobic or anaerobic environments, nutrient concentration, and surface texture to ensure ideal growth and development.

FIG. 5.

B | reactor is a modular platform, which can be configured with different peripherals (e.g., camera, spectrophotometer, and backlit plate) to facilitate liquid and solid-state culturing.

Multimodal culturing is often needed in workflows even if the final output is a liquid culture. Users often receive cells in glycerol stabs or filter disks. The cultures on the disks or stabs then need to be streaked on agar plates to propagate cultures. Single colonies are often picked from streaked plates after 24 h of culturing and transferred into liquid broth where the cultures achieve high cell counts.

The same base unit can provide a temperature-stabilized environment to grow cultures in solid state in petri dishes: 12-, 24-, and 96-well plates. Then the cultures can be transferred into a tube or syringe, where they can be agitated, heated, or cooled. Certain strains or species cannot be cultured in aerobic (oxygenated) environments. The small form factor (i.e., w: 7 inches, h: 7 inches, d: 7 inches) of the B | reactor allows it to fit inside an anaerobic chamber or glove box. The unit can run off a rechargeable battery and be fully immersed in a sealed environment where the cultures can be exposed to other gasses.

The versatility of cultivation options is achieved by using standard disposable tubes, syringes, petri dishes, or plates that eliminate both the need for sterilization infrastructure as well as an advanced liquid transfer system. Organisms can be transferred between storage and culturing environments using syringes with removable plungers. Syringes can also directly attach to a bioprinter’s nozzle for dispensing bioinks.

The standardized vessels can also be augmented with novel scaffolds that can create customized surfaces, structures, textures, or shapes. For instance, 3D-printed scaffolds placed inside the vessel can be used to test biofilm formation and degradation. Yarn or textiles wrapped onto structures can be used to test microbial adhesion and transfer. See the case studies section for examples.

Modularity

The platform offers a modular hardware architecture. Users can configure the system with several peripherals to sense, monitor, or image biological processes (Fig. 6). For example, a spectrophotometer module can be installed to measure the turbidity and optical density and alert the users about the growth rate and quantity of the cells inside the liquid. Similarly, when organisms are grown in a petri dish or plate, an imaging module can track growth kinetics, analyze color changes in assays, or evaluate experimental outcomes (e.g., motility and pattern formation) A customizable illuminator module can be configured for different light intensity, frequency, and wavelengths. Light activation can be used to trigger optogenetic circuits tuned to wavelengths. UV-B and UV-C lights can be activated for sterilization-in place. IR and NIR can be used for imaging species that are sensitive to the visible light spectrum.

FIG. 6.

In Microbial Design Studio, microorganisms are introduced via standardized electroporation cuvettes. Liquid handling is done with a rotational platform equipped with motorized syringes. The platform handles flow control to automate all stages of microbial design. Prototype version 3 simplified the purification section and replaced the centrifuge with a motorized media removal carousel.

Usability

Another bottleneck that limits the adoption of biobased additive manufacturing is access to biological know-how. Designers often lack the skills and training to execute biological protocols to grow cultures. The B | reactor offers a user-friendly solution by providing a range of preprogrammed recipes that ensure the precise environmental conditions—such as temperature, humidity, and light exposure—required throughout the growth process. Users can load the ingredients into the reactor and initiate an experiment with a keyfob. The hardware retrieves the predefined setpoints from a database and guides various actuators and sensors to communicate their data to a dashboard, enabling users to monitor the experiment’s different stages remotely.

Furthermore, users have the flexibility to design their own recipes based on existing templates using a recipe builder interface. This feature allows them to customize time intervals for setpoints and specify hardware settings, enhancing adaptability and ease of experimentation. In addition, users can easily share these recipes, facilitating reproducibility and collaboration. For instance, a B | reactor located in a biology lab can generate a recipe that can be shared, downloaded, and utilized in a fabrication lab, fostering collaboration among faculty, students, and researchers in designing, evaluating, and applying biological processes in a continuous feedback loop.

Reproducibility

Material or product design projects can also extend beyond the lab or studio space. B | reactor can take experimentation into the field. It allows culturing activities to be done in a remote location such as a forest, factory, or construction site where timely access to specialized raw materials, tools, or biological resources is highly valuable. Furthermore, the platform facilitates the establishment of a networked ecosystem with multiple B | reactors distributed across different locations or geographies. In this networked fashion, researchers can either replicate or validate each other’s work by utilizing similar recipes, or they can distribute experiments across multiple units to create a parallel high-throughput research environment. As individual units generate data or outcomes from their biological processes, this information can be effectively leveraged to inform and optimize various stages of the manufacturing process, promoting collaboration and data-driven decision-making.

Case Studies

The following cases are selected to demonstrate the use of B | reactor for culturing microorganisms and materializing them into designs in apparel, sensor, and material design. These cases serve as examples of how the inherent logic of biological processes—such as self-assembly, biofilm formation, and biodegradation—and the algorithms that control the fabrication environment can be in a feedback loop. This loop is instrumental in executing recipes, fine-tuning processes, and enhancing overall outcomes and objectives.

Microbially dying yarn

B | reactor was employed by a fashion creative enthusiast to explore the creation of custom dyes using yeast (see Fig. 7). The primary objective was to showcase the entire workflow within a studio environment and determine its feasibility without the need for access to specialized laboratory infrastructure for sourcing, cultivating, and disposing of biological materials. The specific design goal was to cultivate enough cultures to dye approximately 30–50 inches of unbleached cotton-based yarn, which would then be manually stitched onto second-hand denim. Figure 8 provides an overview of the workflow detailing the process of materializing bacteria, from obtaining cultures in glycerol stock to stitching microbially dyed yarn onto denim.

FIG. 7.

B | reactor is growing microbial dyes at a textile studio.

FIG. 8.

Design workflow for dyeing yarn with microorganisms using B | reactor.

The yarn was attached to a 3D-printed scaffold made from polylactic acid (PLA). The scaffold geometry was designed as a two-part piece on which yarn is wrapped onto notches spaced apart to allow yarn to expose more surface area. While the scaffold could be sterilized with exposure to 70% ethanol, the yarn was not. So, after several trials, yarn was sterilized using a commercial autoclave at a biosafety level 2 lab. The yarn was wrapped onto the scaffold under aseptic conditions and shipped back to the designer as a consumable ready to be inserted into the tube.

The cultivation durations at each stage were determined through experimentation and hold potential for further optimization. In Stage 3, a camera system was employed for systematic observation of colony formation within the multi-well plate. Individual colonies were isolated based on their pigmentation strength and the speed at which the yeast expressed color. This information guided the estimation of the required duration for cultures to be exposed to the yarn in Stage 6. During Stage 5, a spectrophotometer measured yeast growth by monitoring changes in the turbidity of the liquid within the tube. The tube was agitated with a motor using a 270-degree sweeping motion. In Stage 7, the cultures were removed, and the dyed yarn was subjected to potassium aluminum sulfate, serving as a mordant agent to fix the dye onto the yarn.²⁸ B | reactor was raised to a temperature of 80°C to facilitate mordant treatment and enhance dye fixation.

It was observed that the wrapped yarn hindered complete dye penetration and resulted in some inconsistencies in coloring. This challenge could potentially be addressed by adjusting scaffold geometry, reducing the number of turns of yarn on each notch, or decreasing the length of yarn dyed within a given time frame.

Biodegrading coatings for sneaker design

In this study, B | reactor was used to explore the selective degradation of a starch-based material to prototype a novel sneaker upper sole design. This workflow was carried out at a product design studio equipped with 3D printers (Fig. 9). Logistic dependencies were carefully evaluated, and the only external equipment needed was identified as a commercial flow hood to provide an aseptic environment as well controlling the lighting conditions for imaging.

FIG. 9.

Design workflow for prototyping a custom biodegradable coating for sneaker upper sole using B | reactor.

The premise of the upper sole design was based on coating a 3D-printed scaffold with a paste inoculated with Saccharomyces cerevisiae var. diastaticus. Our hypothesis centered on the idea that, under specific environmental conditions encompassing CO₂ levels, temperature, and moisture content, the yeast would digest the thin layer of paste, eventually exposing the pores on the nondigestible 3D-printed scaffold. This process would result in the creation of a unique surface pattern.

This yeast strain, commonly employed in the brewing industry, possesses a unique attribute: it utilizes dextrin as a nutrient source. Diastaticus, while typically considered a contaminant in conventional beer production due to its potential to cause unexpected beer can explosions, stands out due to its ability to degrade dextrin. Notably, this organism is reported to have three additional genes (STA1, STA2, STA3) that enable it to synthesize the enzyme glucoamylase, which it employs to break down sugar in the environment as an energy source.²⁹

Following an initial set of manual experimentation, B | reactor was used to vary the environmental conditions—primarily temperature, humidity, and airflow—to estimate a baseline degradation rate. Water was provided manually with small cups placed under the backlit plate. We assessed the degradation rate of 0.1-, 0.2-, and 0.3-mm layers of paste over a 72-h period. Subsequently, a week-long longitudinal study was conducted to optimize the moisture retention of the 0.2-mm film. Another study was undertaken to evaluate the impact of a commercial whey-based waterproofing stain on reducing water evaporation.³⁰ This stain was applied to both sides of the paste, resulting in a significant reduction in surface cracking. The evaluation of all experiments was carried out using machine vision, which analyzed the degraded areas on the surface using “blob” detection, during the growth process.³¹

The surface was periodically imaged, and the largest blobs were tracked over time to calculate a degradation rate (see Fig. 10). The image analysis capabilities of the platform are built into a camera module, which is equipped to run OpenCV algorithms to do surface roughness, texture, or shape analysis.

FIG. 10.

B | reactor’s dashboard analyzing the changes in the pore sizes as a starch-based coating is degraded by Saccharomyces cerevisiae var. diastaticus.

Discussion

Both cases are selected to showcase the use of biologically-active ingredients to realize novel designs with an emphasis on design workflows that minimize the need for professional biology labs. Figure 11 provides a list of requirements to execute the designs and a series of findings that were learned at the end of each case study.

FIG. 11.

Case study summary.

The end products were considered proof of concepts to demonstrate the technologies, not the efficacy or performance of the designs. It was also important that the cases did not require and specialized microbiology skillset and know-how such that a fashion creative and sneaker designer can focus on the design process and work in their design studios next to their 3D printers, and sewing machines, and so on.

Conclusion

In this article, we discussed a framework to consider bioreactors as additive manufacturing environments. We have emphasized two key distinctions that set them apart from traditional fabrication tools. First, bioreactors excel in their ability to engage with the dynamic agency of living ingredients. We have argued that “materializing” living matter fundamentally diverges from working with inert materials. Second, we have distinguished bioreactors from mere tools by highlighting their role as comprehensive “environments.” These environments facilitate intricate feedback loops between algorithms, biology, and mechanical systems, providing the essential conditions for realizing biobased designs.

To illustrate these concepts, we have presented two bioreactor platforms, namely the Microbial Design Studio and B | reactor. Both systems share the common goal of making biobased design accessible to nonexperts by simplifying equipment operation and reducing the dependency on specialized biolab infrastructure. In addition, we have showcased two workflows where designers utilized B | reactor to cultivate designs in both liquid and solid states. These designs explored the materializing microorganisms by actively paying attention to the interaction between biology and environmental conditions.

Besides what is discussed in this article, there are many other bioreactor, incubator, fuel cell, and growth environment typologies that can be considered as new research areas in additive manufacturing. These environments can either fabricate and materialize designs or grow organisms that can be used downstream in other fabrication tools as raw ingredients, bioinks, and so on. Through this article, our aim has been to draw parallels between traditional additive manufacturing and biobased manufacturing in terms of assembly, addition, and accumulation. Looking ahead, we anticipate the emergence of numerous hybrid fabrication paradigms that leverage the unique capabilities of living and inert materials to bring designs to life across various scales.

Author Disclosure Statement

The author acknowledges that there was no conflict of interest between this research and potential commercial interests of the companies involved. Biorealize Inc., ceased operations before the publication of this article.

Funding Information

The funds used for the research, design, and build of the biomanufacturing platforms Microbial Design Studio and B | reactor were provided by Biorealize.