1 Introduction

The worldwide economic, social, and environmental challenges have led to a significant emphasis on sustainability. The concerted efforts of architects and research scientists in advancing green materials and leveraging sustainable bio-based resources have indeed yielded significant improvements. Through their commitment to waste reduction and the use of environmentally benign, renewable, economically viable, long-lasting, and repurposed materials in architectural designs, they are laying the groundwork for a future that is both sustainable and resilient. [1].The interconnection of nature with the man-made technologies by developing bio-composites and green materials will be the most enduring solution for solving environmental concerns and sustainability issues [2, 3].

Emphasizing self-sufficiency in environmental activities, including recycling, environmental purification, climate action, CO2 reduction, and conservation, holds paramount significance. Additionally, extending this focus to architecture by incorporating green sustainable alternatives aligns with the broader goal of fostering a balanced and sustainable relationship with the environment.[4,5,6]. In order to achieve noticeable changes in converting creative design ideas to physical artifacts, material thinking that entails accessible, cost-effective and sustainable solutions creating an environmentally responsive architecture with a high level of integration among shape, material and structure across scales must be implemented [7, 8].

Environmental sustainability has marked the attention for the enhancement of biomaterials specifically Bacterial Cellulose (BC) within the interior design industry. Bacterial cellulose which can be also named microbial cellulose is an eco-friendly material that has unique interconnected network with highly versatile three-dimensional carbon nanomaterials [9].This nano-biomaterial has the ability to biodegrade easily and considered one of the highest performance sustainable (going green) material since it is synthesized by several organisms such as yeasts, bacteria, molds and from everyday use reachable components such as sugar and tea [8].

Cellulose is considered an abundant and rich natural polymer that can be synthesized through oxidative fermentation by bacteria from the genus Gluconacetobacter, Sarcina, and Agrobacterium. Kampuchea tea fermentation arises as an excellent approach for the production of bacterial cellouse due to the interplay of the SCOBY (The Kampuchea symbiotic community of bacteria and yeast), Kampuchea tea is a known probiotic beverage which is obtained through fermentation of sugared black tea with the SCOBY for 7–16 days at ambient temperature [10]. Innovative advancements in culture methods, media formulations, fermentation techniques, and bioreactor designs have been documented, which significantly contribute to the improvement of the production and utilisation of novel materials such as Bacterial Cellulose (BC) in diverse domains, including Architecture Design. These technological improvements play a significant role in enhancing the growing environment for cellulose-producing bacteria, resulting in enhanced yields and increased quality of biochar (BC). Moreover, advancements in bioreactor designs ensure efficient production processes, scalability, and consistency in BC production.

Popa et al. [11]. Besides, for overcoming the high fermentation cost challenge, a promising approach for waste minimization is obtained by utilizing large waste biomass byproducts of several industries like agro, lignocellulose, food, bio-refineries and low-cost substrates as a source of various nutrient for Bacterial cellulose (BC) production [12, 13].

Bacterial cellulose (BC) have distinctive properties for its high degree of crystallinity, high resistance to traction, high purity and great biocompatibility, in addition to its robust physical & mechanical properties as large specific surface area, high mechanical strength, high water holding capacity, outstanding suspension stability, good chemical stability and have high stability towards high temperatures [10, 14]. Moreover, BC consist of fibrous network made from a well-arranged nanofibers that can lead to the formation of hydrogel film with a considerable porosity and large surface area [14, 15]. Hence, BC is deliberated as an ideal choice for fabrication and can be utilized in various applications not only in academic researches but also industrial areas [10].

Through a procedure known as "in-situ synthesis," carbon nanomaterials may be integrated into bacterial cellulose. In this method, the nanomaterials are created inside the bacterial cellulose structure while the bacteria are synthesising the cellulose. Carbon nanomaterial precursors, such as carbon nanotubes or graphene oxide, can be added to the bacterial growth medium to accomplish this. Once the bacteria start synthesizing cellulose, the carbon nanomaterial precursors get trapped within the cellulose structure, resulting in a composite material with enhanced properties such as mechanical strength, conductivity, and biocompatibility. The carbon nanomaterials are connected within the body of the bacterial cellulose through physical entrapment and interactions with the cellulose fibers. The nanomaterials can form strong bonds with the cellulose matrix, resulting in a homogeneously dispersed composite material [16].

The adoption of bacterial cellulose (BC) is widespread in various domains, such as architecture, owing to its biocompatibility, biodegradability, and exceptional characteristics. BC is employed in architecture to produce sustainable construction materials such as panels and insulation, hence promoting environmentally conscious building practices. The versatility of this material is seen in its application within the field of interior design, where it may be seamlessly integrated into acoustic panels, ornamental components, and furniture. Moreover, BC-based composites are utilised in the manufacturing of biodegradable building components, demonstrating their capacity to transform sustainable architectural methods and tackle environmental issues in diverse sectors [17, 18].

2 Research methodology

The methodology of this research is synthesizing Bacterial or Microbial Cellulose with deep investigation to capture the intellectual power of BC to generate soft architectural skin [19, 20]. The methodology phases are displayed in Fig. 1 showing the detailed process steps to attain a Bio Function-oriented design combined with a profound material knowledge [21, 22].

Fig. 1
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Navigating the Process: From Experimental Setup to Final Implementation. The experimental setup and procedures showing the results and the growth of bacterial cellulose is detailed discussed in (Sect. 3), while the mechanical characterization and testing that entails material analysis is deliberated in (Sect. 4). lastly the possible implementation in growing Architecture and other applications is shown in (Sect. 5). However, the prototyping and design challenging the properties of BC in order to visualize the potential architectural application or the direct implementation of the final system framework will be fulfilled in the future research

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3 Experimental work

3.1 Materials and chemicals

All chemicals used in this study were of purchased from Sigma Aldrich (Germany) (D- Sucrose 99.5% purity) and Tea Extract (acetic acid bacteria strain) were used without further purification. All solutions were freshly prepared using distilled water.

3.2 SCOBY cultivation technique

The medium for growth of SCOBY should necessarily contain a carbohydrate component as the carbon source and tea extract as a nitrogen source so that it can be assimilated in the fermentation process for cellulose production and microbial growth. Camellia sinensis is the scientific name of tea extract beside alkaloid content represented by caffeine it also contains fermentation yielded black tea polyphenols like catechin [23]. The most widely used carbon source is sucrose, hence, the cultivation of kombucha SCOBY has been investigated in this paper in two different experiments [24] [1]. Figure 2.

Fig. 2
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The meticulous process of cultivating and characterizing SCOBY

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3.2.1 Testing the optimum sugar -sucrose- amount

The first experiment was carried to find the optimum sugar (sucrose) amount.as on Fig. 3 1 Liter of distilled water was heated to a boil, afterwards, 4 g of black tea were added and left to brew for 5 min. After cooling, 7 batches of (100ml each) of the tea solution were placed in separate containers. Then the same amount of kombucha SCOBY layer was added to each container, with different concentrations of sucrose (5, 10, 15, 20, 25, 30, 35 g/ml solution) keeping the pH = 2.3 using acetic acid -vinegar-[25, 26].

After waiting for 16 days, the 7 containers were checked to examine the growth of SCOBY layer, as shown in Fig. 3.

Fig. 3
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Preparation of tea solution with different Sugar Concentration

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The growth rate was observed and plotted in Fig. 4. After drying the SCOBY for one week at room temperature the thickness of the layer. And in Fig. 5 From this graph, it is concluded that the optimum sugar concentration is 150g/L.

Fig. 4
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Samples after Drying 16 days

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Fig. 5
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Plot showing Sugar Concentration versus Thickness. Thickness of bacterial cellulose formed (SCOBY layer thickness)

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3.2.2 Integrating growth with jute fiber to create BC composite

In the second experiment, 1 Liter of distilled water was heated to a boil, afterwards, 4 g of black tea were added and left to brew for 5 min. The optimum amount of sugar was added to the solution (150 g/L, based on the previous experiment). After cooling, the tea + sugar solution was divided equally into 2 containers Figure 6.

Fig. 6
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Experimental Preparation

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In pottery plate (A), 1 layer of SCOBY bio-film was placed on the bottom of the plate, followed by 1 layer of Jute Fiber Fabric with dimensions of 10 × 15 cm, while In pottery plate (B) 1 layer of jute fiber was placed in between two layers of SCOBY bio-film. The jute fibers used are a naturally processed untreated plain woven jute fibers. Figure 7

Fig. 7
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Photos of jute after & before the experiment & after 16 days

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It was observed that In pottery plate (A), the SCOBY BC layer had high adhesion with the jute fibers, with visible permeation of grown film through the gaps in the fabric. In pottery plate (B) the SCOBY BC layer had grown but with no adhesion to the jute fabric. Therefore, the results show that one layer of SCOBY under the jute fiber layer can grow successfully, creating a SCOBY BC + Jute fiber composite.

3.3 Field emission scanning electron microscopy characterization

To investigate the attachment of SCOPY on burlap, images were acquired at different magnifications using FESM. The selection of magnification levels allowed for a comprehensive examination of the SCOPY attachment phenomenon, capturing both macroscopic and microscopic details of the material surface. At higher magnifications, the images revealed intricate features of the SCOPY attachment, providing a closer look at the individual fibers and their interaction with the burlap substrate. Conversely, lower magnifications offered a broader view, enabling the assessment of the overall distribution of SCOPY across the sample.

4 Mechanical characterization

Mechanical characterization is a critical step in discovering the potential for any developed material. For the developed SCOBY BC bio-film, determining properties like tensile strength, ductility and density with standardized methods provides an accurate overview about its load bearing capacities and weight, hence revealing its degree of fitness in the potential applications. Figure 8 shows the FESM for the prepared material with different magnifications.

Fig. 8
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FESM for the prepared material with different magnifications

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For this investigation, three materials are tensile tested to determine their maximum breaking strength and ductility (represented in %Strain): neat SCOBY BC bio-film, natural jute fabric, and SCOBY BC bio-film + jute fabric composite. Figure 9 shows the structure of the SCOBY bio-film with different magnifications using an optical microscope. The neat SCOBY properties provide the capabilities of the material itself without any reinforcement. The properties of the SCOBY biofilm + jute provide the potential for reinforcement of SCOBY bio-film with natural fibers. The SCOBY composite consists of 1 layer of SCOBY bio-film and 1 layer of untreated woven jute fiber, which corresponds to weight fractions of approximately 80% jute and 20% SCOBY. The jute fabric used is an untreated natural plain woven jute. Figure 10 shows the sheets from which the tensile specimens were cut according to the test standards. The cutting of the specimens was done using a razor blade in order to produce a sharp dimensionally accurate cut. From each sheet, Fig. 11 shows samples of the tensile specimens. In order to minimize the experimental error, three specimens are tested from each material and the average results were taken. Figure 12 shows one of the specimens during the tensile test Table 1 summarizes the standards followed for the procedure.

Fig. 9
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Microstructure of SCOBY bio-film with different magnifications

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Fig. 10
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Material Sheets—From left to right: Jute + SCOBY, Jute Fabric, Neat SCOBY

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Fig. 11
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Material Sheets—From left to right: Jute + SCOBY, Jute Fabric, Neat SCOBY Bio-Film

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Fig. 12
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One of the samples during the tensile test

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Table 1 Test standards followed
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4.1 Results and discussion

The tensile test results showed that the prepared neat SCOBY bio-film had a maximum tensile strength of 5 MPa and a corresponding maximum tensile strain percentage of 8%. Regarding the jute-SCOBY composite, the tested samples had an average tensile strength of 10 MPa and a corresponding maximum tensile strain percentage of 6%. Figure 13 shows the tensile stress–strain curves for the three materials tested. Figure 14 Shows the tested specimens after failure. It can be seen from the stress–strain behavior that the jute-fiber positively reinforced the SCOBY bio-film, increasing its tensile strength by 100%, but decreasing its ductility by 25%. This decrease in ductility is due to the brittle nature of the jute fiber, which is clear in the jute fiber stress–strain behavior. This significant increase in the tensile strength enables the SCOPBY bio-film to handle more load, facilitating its use in more architectural applications, especially if the decrease in ductility is an acceptable compromise. For example, the higher tensile strength will enable the film to withstand more wind loads in the case of low-cost biodegradable tents [27, 28].

Fig. 13
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Stress–Strain curves of the tested materials

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Fig. 14
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Tested samples after failure—Top: SCOBY Biofilm—Bottom: SCOBY + Jute Composite

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4.2 Validation of the results

Other researchers have carried out similar experimental research on SCOBY films to assess the mechanical properties, for example [29] prepared cellulose biofilms using sucrose and tea extract, their the produced bio-films had tensile strengths ranging between 0.1 and 0.2 MPa. The tensile test results in this research and within the range of results from [29, 30]. Jurgita et al. [30] also prepared film samples using sucrose and green tea; their bio-films had tensile strengths ranging between 0.4 and 27 MPa. The variation of the results for the same experimental research and in-between researchers can beiboth explained by high sensitivity of the produced film to variations in the growth conditions. A Krystynowicz et al. [31] studied the factors affecting the yield and properties of bacterial cellulose. Their results showed that the yield and properties are highly dependent on several different factors including but not limited to growth time, aeration, agitation, temperature of the growth medium, pH of the medium, type and amount of sugar used, strain of bacteria, and drying methods. Their results also showed that even slight variations of 0.5% in some of these factors lead to large changes in the amount of yield and properties of films as shown in Table 2.

Table 2 Summary of the properties of the tested materials
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Additionally, another important observation regarding the growth of films was noticed during the experimental work done here and previous work by other researchers; the produced films had varying thicknesses and micro-defects within the same growth batch. For example, the SCOBY bio-film shown in Fig. 14 shows light and dark locations, the darker locations have comparatively higher thickness which is likely to cause variation in mechanical properties, especially tensile strength. This variation can be mathematically reduced by measuring the thickness for multiple locations within the same specimen and then taking the minimum or average thickness in the equations of stress. An example of a micro-defect is shown in Fig. 15 where there are small air-bubbles resulting from the natural growth of the bacteria. These air-bubbles act as stress concentration sites where micro and macro failure is likely to occur first, decreasing the overall strength of the films [28]. Figure 16 shows Possible implementation of bacterial cellulose in architecture applications.

Fig. 15
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Mico air bubbles in the SCOBY bio-film

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Fig. 16
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Possible implementation of bacterial cellulose in architecture applications

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Expanding the utilization of Bacterial Cellulose (BC) as a self-sufficient basic material in the field of Architecture Design entails a multitude of potentialities and factors to be taken into account. (BC) exhibits a notable degree of sustainability, rendering it a promising material for numerous architectural uses on a wide scale. The employment of this resource, being both biodegradable and renewable, has the potential to significantly mitigate the environmental consequences associated with the construction sector Due to its robustness and longevity, it serves as a feasible substitute for conventional construction materials. Besides, the broad range of applications for this material enables its use in several domains such as structural components, insulation, coatings, and interior design elements. Moreover, it held Prospects for Innovative Design, the incorporation of sophisticated construction technologies, such as 3D printing and digital fabrication, significantly augment the suitability for BC in architectural applications on a broad scale. Furthermore, it helps in Carbon Footprint Reduction, the renewable nature and reduced environmental impact of this choice make it highly appealing for sustainable building techniques [1, 32].

In order to expand the production of BC, it would be imperative to enhance the cultivation of cellulose-producing bacteria. To address the growing need for architectural applications, it is feasible to accomplish this objective through the implementation of optimised fermentation techniques and the expansion of production infrastructure. Furthermore, it is advisable to consider the establishment or modification of regulatory frameworks to ensure the secure and efficient use of BC in architectural design, given its growing prevalence. The achievement of widespread acceptance will be contingent upon the assurance of compliance with construction rules and standards. Additionally, this may require collaborations among experts in biology, architects, engineers, and manufacturers. The promise for interdisciplinary collaboration lies in its ability to foster innovation and enable the integration of BC into traditional construction practices. When examining the extensive utilisation of Bacterial Cellulose (BC) in the field of Architecture Design, it is important to acknowledge and tackle several constraints. These obstacles encompass issues pertaining to production capacity, cost factors, material characteristics and standardisation, adherence to regulations, durability and long-term performance, integration with current construction methods, and the environmental consequences of cultivation. Addressing these constraints via additional study, technological progress, and industry cooperation is imperative in order to enhance and broaden the application of BC in extensive architectural endeavours, hence facilitating the development of a more sustainable and inventive constructed environment [1, 33].

5 Possible implementation in growing architecture and other applications

Biomaterials like BC have unique features that make them able to easily to integrate with design and architecture to make prototypes towards more sustainable solutions due to the ability of BC to self-assemble and self-heal and its multi-functionality, it was reported that BC is a remarkable solution for building the environment since it can be used as façade material in architecture designs due to the high water resistance ability. Furthermore, as shown in the following figure, BC has leather like appearance with high mechanical strength which make it a promising alternative that can be used in interior design architecture, for instance as a part of furniture design, seating chairs that can endures the weight of man, tables, etc. [34]. As a proof a study was done on xylinum bacteria about designing a framework for creating the cellulose fiber structure around wooden scaffolding [22].Similarly, the use of BC as leather alternative make researchers exploit it in finished products as coats, shoes, wallet and handbags, this leather like structure is obtained by the combination the model strain K. xylinum microorganisms that forms pellicles of cellulose which accumulates in extracellular medium [25, 35]

Reports stated clearly that BC has high stability towards high temperatures which make it a perfect candidate in making lights, replacement of plastic lamps or designs that need a suitable material when contacted with light [36,37,38]. Moreover, research studies about fiber reinforcement showed that fibers can be added through the growing process after the drying of a thin layer of cellulose to make a higher strength to the material [34, 39]. Other reports showed the importance of BC in packaging industry or as a raw material for films on the ground of its biodegradability, chemical stability, biocompatibility,non-toxicity, and renewability [40]. It was revealed that BC in Food packagingas instance is a successful approach since a test was done on dried biofilm sheets which covers storing vegetables, it was found that all vegetables and fruits were found to be fresh for a period of 8 days (2019) [41]. Besides, other study showed that BC is it can be remarkably versatile biomaterial has unique nanostructure and properties utilized for forming medical devices, sensors, biodegradable tissue scaffolds, flexible electrodes, organic light-emitting diode displays and wide range of applied scientific endeavors & tissue-engineered applications [22, 42].

A comparative analysis between the performance different promising materials as ethylene tetrafluoroethylene ETFE and Bacterial cellulose BC was studied which showed some similarity between them in that not only (ETFE) can be used with more durability as an alternative for glass and can be used in architectural context in Façades or roofs, but also BC is a promising substitute since they have extraordinary properties, for instance eco-friendly and high levels of stability, flexibility and, thermal insulation [43]. Moreover, ETFE is recognized by architects and designers as one the most innovative materials in the frame of modern architecture and is used as an inspiration for novel concepts that impact structural design for instance, ALLAINZ ARENA stadium, ETFE roofing of Burges Zoo ETFE cushions and ETFE facade systems. Similarly BC will be a future alternative that will solve environmental difficulties and will be degraded without leaving environmentally harmful footprints [43] [38, 44].

6 Conclusion

Recently, a noticeable escalation in sustainable practices and materials to diminish the negative impacts and carbon footprint accompanying with construction. In this research, the objective was the combination of interdisciplinary knowledge of science and architecture to form bacterial cellulose (BC) ecofriendly, novel, sustainable and smart material. Bacterial cellulose was experimentally synthesized, tested by mechanical testing and modified. The results indicate that the optimum sugar concentration is 150g/L. The mechanical characterization showed that the produced SCOBY bio-film had a tensile strength of 5 MPa and a maximum strain of 15%. Additionally, the SCOBY BC bio-film was successfully reinforced with jute fibers, increasing its tensile strength by 100% to reach 10 MPa. Overall, the mechanical properties of the neat SCOBY BC bio-film and its jute-fiber composite enable both materials to be used in a wide variety of applications, making them a low cost, sustainable and biodegradable material option.