Week 1 HW: Final Project Ideas
HTBAA Homework 1
Bacterial Cellulose and Post Consumer Textile Waste Biofoam
Author: Emma Briones Riquelme
Date: September 2026
1 What would you like to biomanufacture and why
I would like to biomanufacture a composite material from bacterial cellulose and post-consumer textile waste for modular, non-structural interior wall panels. The proposal seeks to harness cellulose-producing microorganisms to generate a fibrous matrix that grows on, around, or between recovered textile fibers, helping bind them together and transform them into a new material.
This material would be intended primarily for interior architecture applications, including wall coverings and panels with potential acoustic and thermal performance. Potential users include building-material manufacturers, architecture firms, construction companies, and organizations interested in incorporating circular materials into their projects. However, these functional properties must be verified experimentally and are not presented as demonstrated outcomes of the proposed system.
My interest arises from developing Claris, a project in which I work with biopolymers and textile waste to produce interior panels. This experience has allowed me to recognize both the potential of textile waste as a raw material and the difficulties associated with conventional or biobased binders, particularly fiber cohesion, porosity, moisture resistance, dimensional stability, and the durability required of construction materials.
The proposal addresses a global-scale problem. An estimated 92 million tonnes of textile waste are generated each year, and in 2023 only 8% of textile fibers produced came from recycled sources (United Nations Environment Programme [UNEP], 2025). In Chile, average clothing purchases increased from 13 garments per person in 2015 to 50 in 2020. Textiles may also account for nearly 7% of municipal solid waste, equivalent to approximately 572,119 tonnes per year (Ministerio del Medio Ambiente [MMA], n.d.).
Figure 1. Textile waste accumulated in the Atacama Desert. Note. Photograph by Tamara Merino. Reproduced from Atacama: de majestuoso desierto a enorme basural de moda fast fashion, by J. Bartlett, 2023, National Geographic.
Biomanufacturing offers the possibility of exploring a matrix that is not merely mixed with the waste but produced directly by a living system and developed in contact with the textile fibers. Bacterial cellulose is particularly promising because of its nanofibrillar structure, its ability to form continuous networks, and its potential to integrate with other fibrous materials (Lahiri et al., 2021).
Previous studies have examined textile waste as building insulation (Briga-Sá et al., 2013) and the production of low-thermal-conductivity bacterial cellulose aerogels (Fleury et al., 2020). However, the integration of compositionally variable post-consumer textile waste into a porous bacterial cellulose matrix for interior panels remains underexplored.
The objective is not to claim that bacterial cellulose can immediately replace the binder currently used in Claris, but to investigate whether it could serve as the primary matrix, a reinforcement, or a complementary component. The main questions are whether cellulose can grow uniformly between the fibers, how much waste can be incorporated without losing porosity, and how the combination affects cohesion, moisture response, fire behavior, durability, and thermal and acoustic performance.
As an architect, I am interested in developing new materials that contribute to energy efficiency and habitability. In an insulating material, porosity can immobilize low-thermal-conductivity air, while tortuosity hinders heat transfer. Performance also depends on density, pore connectivity, fiber orientation, and moisture content (Jelle, 2011). This work becomes increasingly relevant under future climate scenarios in which extreme heat events may compromise indoor comfort and safety (Intergovernmental Panel on Climate Change [IPCC], 2022).
In this way, the project would use biomanufacturing to explore new relationships among living organisms, waste, and architecture, advancing toward materials whose structure is partially grown rather than produced exclusively through conventional manufacturing processes.
2 What living system would you use
I would use a cellulose-producing bacterium from the genus Komagataeibacter, with K. xylinus as the reference organism. These aerobic bacteria convert sugars available in the culture medium into an extracellular cellulose network. Under static culture conditions, this network forms mainly at the air-liquid interface, where oxygen is more readily available. Final strain selection would depend on yield, availability, safety, compatibility with the textiles, and culture stability (Lahiri et al., 2021).
The process would begin by sorting the textile waste according to composition, followed by washing, drying, removal of non-textile components, and shredding. Fiber type and size would be recorded because these variables may affect distribution, oxygen availability, and material cohesion.
A culture medium containing water, a carbon source, and the nutrients required for bacterial growth would then be prepared. After adjusting the pH and sanitizing or sterilizing the system, the K. xylinus inoculum would be introduced.
Two integration routes would be compared. In the first, textile fibers would be distributed in trays and the cellulose would grow directly on and around them. This route would allow in situ biomanufacturing to be evaluated, although oxygen transfer and uneven growth could become limiting factors. In the second, cellulose would be cultured separately, disintegrated into a suspension, and subsequently mixed with the textile fibers. This alternative would provide greater control over composition and homogeneity but would require more conventional processing steps.
Temperature, pH, time, oxygen availability, and possible contamination would be monitored during cultivation. Once the cellulose network had integrated with the fibers, the material would be washed and purified to remove cells and culture-medium residues, producing a clean, inactivated biocomposite.
A porous structure could be created through physical foaming or controlled drying that prevents pore collapse. The material would then be molded, dried, and cut to obtain a dimensionally stable panel.
The product would be characterized through measurements of density, porosity, thermal conductivity, acoustic absorption, hygrothermal behavior, mechanical resistance, reaction to fire, and durability. The purpose of this sequence is not to assume that the material will work, but to compare both routes, identify their critical variables, and determine whether the biological integration hypothesis is viable.
3 How would you use automation
Automation would serve two purposes: accelerating experimentation and improving the repeatability of future production. I would not automate the entire process from the outset; I would first identify which variables account for most of the differences among samples.
During the experimental stage, I would use an automated liquid-handling system, such as Opentrons, to prepare variations of the culture medium, inoculate replicates, and conduct small-volume experiments. This would enable comparisons among carbon sources, pH levels, inoculum concentrations, textile proportions, and fiber sizes while reducing dosing errors.
The culture system would be complemented by temperature, pH, and oxygen sensors, together with continuous recording of environmental conditions. Periodic photography under controlled lighting would allow surface coverage, color changes, contamination, and material shrinkage to be observed. Each sample would have an identifier linked to its formulation, culture conditions, and final properties.
Automation would connect three groups of information: the formulation used, the actual process conditions, and the performance of the resulting material. Its value would lie not only in producing more samples but also in generating comparable data to identify which variables must be controlled during scale-up.
At the pilot stage, the liquid-handling robot would be replaced by modular trays, semi-automated dosing, and environmental control. Post-processing would require monitoring pressure, temperature, moisture, and mass to determine the end of drying and maintain consistent density and thickness.
Automation would be introduced progressively. It would first be used to understand what controls the material and then to reproduce those conditions at a larger scale. Automating the process before understanding its critical variables could increase production speed without resolving its biological variability.
4 How much would you need to make and how long would it take
a How much
Two scales are considered: a 1 m² demonstrator to validate the process and 20 m² to estimate its application in a pilot room. Preliminary parameters include a thickness of 0.020 m, a dry density of 50 kg/m³, and a composition of 60% textile waste and 40% bacterial cellulose. These are design assumptions and must be adjusted based on experimental results.
Dry mass is calculated as follows:
For 1 m²:
The panel would require approximately 0.60 kg of textile fibers and 0.40 kg of dry bacterial cellulose. With a 20% production margin, 0.48 kg of cellulose would need to be produced. If a provisional yield of 5 g dry cellulose/L is assumed, the required volume would be:
For a 20 m² pilot room:
This production would correspond to 12 kg of textile waste and 8 kg of bacterial cellulose. Including the 20% margin, 9.6 kg of dry bacterial cellulose would be required:
Rather than establishing definitive nominal values, this calculation identifies the variables that govern scale-up: thickness, density, cellulose proportion, biological yield, and process losses.
b How long
As a preliminary scenario, a parallel capacity of 480 L is considered, equivalent, for example, to 24 trays containing 20 L of medium each. This equivalence is used only to size the process. In static bacterial cellulose cultivation, productivity depends not only on volume but also on the available area at the air-liquid interface and on oxygen transfer.
At this capacity, producing the equivalent culture volume of 1,920 L would require:
If each cultivation cycle lasts approximately 10 days:
Including fiber and medium preparation, inoculation, purification, forming, drying, and quality control, the total time is preliminarily estimated at 55 to 65 days.
During prototyping, automation would be used to prepare formulations, control variables, and compare small samples. Pilot production would require replacing this system with modular trays, environmental sensors, and semi-automated dosing, washing, and drying operations.
The primary purpose of this estimate is not to predict industrial capacity but to identify the process bottleneck. The first experiments should therefore measure productivity as grams of dry cellulose per liter, per unit of culture surface area, and per day. These data would replace the initial assumptions and indicate whether scaling the material is technically and energetically viable.
5 What do you not know yet
The first uncertainty is whether bacterial cellulose can grow continuously and adhere around textile waste of variable composition, particularly natural, synthetic, and blended fibers. This would be evaluated by comparing direct growth on the fibers with the incorporation of cellulose produced separately and by observing material coverage, penetration, and distribution.
The second uncertainty concerns the relationship among composition, porosity, and cohesion. A higher fiber content could improve reinforcement, but it could also disrupt the cellulose matrix or create weak areas. The proportions of both components must therefore be varied and their density, porosity, strength, and thermal and acoustic performance measured.
The third uncertainty is the material’s stability under moisture exposure and aging. Bacterial cellulose is hydrophilic, so the panel could absorb water, deform, or support biological growth. This condition would be studied through absorption, water-vapor, hygrothermal-cycle, dimensional-stability, and reaction-to-fire tests.
In summary, the priority questions are: Can bacterial cellulose bind textile waste of variable composition? Which combination can preserve both cohesion and porosity? Can the material maintain its properties over a service life compatible with an interior application?
Use of AI
I used ChatGPT, developed by OpenAI, as a support tool to organize the document, improve the clarity of the writing, and verify the reference format. The idea, design decisions, assumptions, and interpretation of the project are my own. Artificial intelligence was not used to generate experimental results or replace review of the original sources.
The main prompts used were:
- “Review the bibliography of the assignment document and provide a summary of each source.”
- “Develop the quantity and time calculation, prioritizing the reasoning criteria over nominal values.”
- “Review the text as if you were an MIT evaluator selecting proposals for integration into research nodes.”
- “Reduce the content to the information strictly necessary to understand and evaluate the proposal.”
- “Review the references and correct their APA 7 formatting.”
The generated responses were reviewed, revised, and verified before being incorporated into the document.
References
Briga-Sá, A., Nascimento, D., Teixeira, N., Pinto, J., Caldeira, F., Varum, H., & Paiva, A. (2013). Textile waste as an alternative thermal insulation building material solution. Construction and Building Materials, 38, 155–160. https://doi.org/10.1016/j.conbuildmat.2012.08.037
Fleury, B., Abraham, E., De La Cruz, J. A., Chandrasekar, V. S., Senyuk, B., Liu, Q., Cherpak, V., Park, S., ten Hove, J. B., & Smalyukh, I. I. (2020). Aerogel from sustainably grown bacterial cellulose pellicles as a thermally insulative film for building envelopes. ACS Applied Materials & Interfaces, 12(30), 34115–34121. https://doi.org/10.1021/acsami.0c08879
Green Product Award. (n.d.). Bacterial cellulose foam. https://www.gp-award.com/es/projects/bacterial-cellulose-foam
Intergovernmental Panel on Climate Change. (2022). Climate change 2022: Impacts, adaptation and vulnerability (H.-O. Pörtner et al., Eds.). Cambridge University Press. https://doi.org/10.1017/9781009325844
Jelle, B. P. (2011). Traditional, state-of-the-art and future thermal building insulation materials and solutions—Properties, requirements and possibilities. Energy and Buildings, 43(10), 2549–2563. https://doi.org/10.1016/j.enbuild.2011.05.015
Lahiri, D., Nag, M., Dutta, B., Dey, A., Sarkar, T., Pati, S., Basu, D., Abdul Kari, Z., Wei, L. S., & Ray, R. R. (2021). Bacterial cellulose: Production, characterization, and application as antimicrobial agent. International Journal of Molecular Sciences, 22(23), Article 12984. https://doi.org/10.3390/ijms222312984
Ministerio del Medio Ambiente. (n.d.). Textiles. Economía Circular. https://economiacircular.mma.gob.cl/textiles/
OpenAI. (2026). ChatGPT [Large language model]. https://chatgpt.com/
Petzold, C. J., & Mukhopadhyay, A. (2025). From bench to biofactory: High-throughput technologies and automated workflows to accelerate biomanufacturing. Current Opinion in Biotechnology, 94, Article 103320. https://doi.org/10.1016/j.copbio.2025.103320
United Nations Environment Programme. (2025, March 27). Unsustainable fashion and textiles in focus for International Day of Zero Waste 2025. https://www.unep.org/news-and-stories/press-release/unsustainable-fashion-and-textiles-focus-international-day-zero