Engineered living materials

ELMs are materials in which living cells function as structural or active components, enabling behaviours such as growth, regeneration, sensing and self-healing (Gilbert et al. Reference Gilbert, Tang, Ott, Dorr, Shaw, Sun, Lu and Ellis2021; Molinari et al. Reference Molinari, Tesoriero and Ajo-Franklin2021; Nguyen et al. Reference Nguyen, Courchesne, Duraj-Thatte, Praveschotinunt and Joshi2018). Situated at the intersection of synthetic biology and materials science, ELMs leverage biological processes to create responsive and adaptive material systems (An et al. Reference An, Wang, Huang, Wang, Liu, Xun, Church, Dai, Yi and Tang2022; Gilbert and Ellis Reference Gilbert and Ellis2018; Wang et al. Reference Wang, Hu, Li, Liu and Bian2025). Compared to conventional materials, ELMs can self-assemble, repair damage and interact with environmental stimuli (Rivera-Tarazona et al. Reference Rivera-Tarazona, Campbell and Ware2021; Wang et al. Reference Wang, Liu, Li, Chen, Liu and Zhong2022). Recent research has demonstrated their potential across domains, including biomedicine (Lavrador et al. Reference Lavrador, Gaspar and Mano2021; Omer et al. Reference Omer, Mohsin, Mohsin, Mushtaq, Huang, Guo, Zhuang and Huang2022), environmental remediation (Datta et al. Reference Datta, Weiss, Wangpraseurt, Hild, Chen, Golden, Golden and Pokorski2023; Wang et al. Reference Wang, Zhang, Ge, An and Zhong2024), energy production (An et al. Reference An, Wang, Huang, Wang, Liu, Xun, Church, Dai, Yi and Tang2022; Yuan et al. Reference Yuan, Xu, Liu, Zhang, Li, Liang, An, Paternò, Zhang and Tang2025) and construction (Geng et al. Reference Geng, Jia and Li2024; Wang et al. Reference Wang, Hu, Li, Liu and Bian2025). Because ELMs rely on biological growth and self-regeneration, they are often positioned as promising contributors to sustainability, potentially reducing resource extraction and enabling circular material lifecycles (An et al. Reference An, Wang, Huang, Wang, Liu, Xun, Church, Dai, Yi and Tang2022). However, while their transformative potential is widely articulated, many ELM materials remain at relatively low technology-readiness levels, and their long-term environmental performance, scalability and lifecycle impacts require further investigation.

Recent trends in the field of ELMs include diversification of organism types, scaling from microscale to macroscale structures, and increasing emphasis on controllability, durability and functional optimisation (Gilbert and Ellis Reference Gilbert and Ellis2018; Lu et al. Reference Lu, Huang, Cui, Wu, Jiang, Gu, Cao and Yin2024). Despite these technical advances, translation beyond laboratory contexts raises new challenges. While scholars increasingly acknowledge ethical and societal questions surrounding safety, regulation and responsible innovation (Heveran et al. Reference Heveran, Gerlach, Hernandez, Intemann, Meyer, Ajo-Franklin, Charrier, Srubar, Joshi and Nelson2024), empirical and design-oriented investigations of these dimensions remain scarce. One of the few studies addressing public perception highlights the potential “yuck factor,” suggesting that materials incorporating microorganisms may elicit affective responses such as disgust (Intemann et al. Reference Intemann, Lavoie, Elsass, Scott and Gerlach2025), linked to concerns about contamination, naturalness and moral boundaries. Relatedly, Ertürkan et al. (Reference Ertürkan, Karana and Mugge2022) propose a vocabulary for describing living materials across technical, experiential and relational dimensions, reflecting growing recognition that ELMs require new language to articulate qualities such as agency and responsiveness. However, while such conceptual efforts offer important groundwork, systematic design research examining how these dimensions are interpreted and negotiated in practice remains limited. More broadly, integrating living systems introduces uncertainties regarding lifespan, maintenance, user trust and interpretability (Kleiner et al. Reference Kleiner, Oh and Aubin-Tam2025; Molinari et al. Reference Molinari, Tesoriero and Ajo-Franklin2021). As a result, a gap persists between rapidly advancing technical capabilities and a deeper understanding of how ELMs might be meaningfully integrated into everyday contexts, particularly regarding how diverse stakeholders engage with these dimensions during development.

Social dimensions of emerging materials

Research across emerging material domains, including nanomaterials, smart and adaptive systems, and circular bio-based materials, demonstrates that material innovation reshapes not only technical performance but also ecological systems, economic structures, regulatory frameworks and everyday practices (Karana et al. Reference Karana, Pedgley and Rognoli2015b; Poblete et al. Reference Poblete, Romani and Rognoli2024; Rosato and Triana Reference Rosato and Triana2025). In many cases, environmental risks, governance gaps and user-trust issues became visible only after materials were scaled up or embedded in products and infrastructure (Gottardo et al. Reference Gottardo, Mech, Drbohlavová, Małyska, Bøwadt, Sintes and Rauscher2021; Le et al. Reference Le, Salomone and Nguyen2023; Linkov et al. Reference Linkov, Kurth, Hristozov and Keisler2015). These cases illustrate that material development is never purely technical, it reconfigures relationships between materials, users and institutions. In response, scholars argue that the implications of emerging materials should be explored during early development stages (Barati et al. Reference Barati, Karana and Hekkert2019; Ferraro Reference Ferraro, Ferraro, Kääriäinen, Pasold and Morer-Camo2023; Wilkes et al. Reference Wilkes, Wongsriruksa, Howes, Gamester, Witchel, Conreen, Laughlin and Miodownik2016).

Work on materials experience emphasises that sensory qualities, temporality and responsiveness influence how materials are trusted and integrated into practice (Karana et al. Reference Karana, Barati, Rognoli and Zeeuw Van Der Laan2015a). Speculative and critical design approaches further demonstrate that engaging with emerging materials through artefacts and co-creation can surface ecological, socio-economic and future imaginaries before infrastructures stabilise (Tufail et al. Reference Tufail, Wang, Tian, Li, Leung, Uzma, Park and Kim2023). These lessons are particularly relevant for living materials. Like other emerging materials, they promise sustainability and innovation while introducing uncertainties around safety, governance and adoption (Li et al. Reference Li, Fornasiero, Xu, Jia, Xu, Sun, Müllen, Zhang and Novoselov2025; Tang et al. Reference Tang, An, Huang, Vasikaran, Wang, Jiang, Lu and Zhong2021) However, they have the ability to grow, self-repair or have other ongoing biological activities, which challenge assumptions of stability and control, foregrounding questions of agency, care and co-evolution (Zhou et al. Reference Zhou, Doubrovski, Giaccardi and Karana2024). In biodesign, such materials can be conceptualised as Living Artefacts that unfold over time and require relational engagement rather than passive use (Karana et al. Reference Karana, Barati and Giaccardi2020). Despite increasing recognition of these dimensions, structured design approaches for exploring social implications during early-stage ELM development remain limited. In this paper, we use the term societal dimensions to refer to the interconnected ecological, social, economic, experiential and future-oriented considerations that shape how emerging materials are interpreted, governed and integrated into everyday life.

Co-design workshops in multidisciplinary settings

Co-design has become a widely used approach for exploring emerging technologies, particularly when they introduce uncertainty, complexity or open-ended future implications (Avila-Garzon and Bacca-Acosta Reference Avila-Garzon and Bacca-Acosta2024). By bringing together participants from different disciplinary backgrounds, co-design workshops create structured environments for mutual learning, shared framing and collaborative concept development (Bisson and Perondi Reference Bisson and Perondi2024; Penuel et al. Reference Penuel, Allen, Henson, Campanella, Patton, Rademaker, Reed, Watkins, Wingert and Reiser2022; Steen Reference Steen2013; White et al. Reference White, Deevy, Casey, Patocs and Raina2023). Rather than assuming a common language, such workshops function as translation spaces in which participants negotiate terminology, assumptions and problem framings across fields (Calvo and Sclater Reference Calvo and Sclater2021; Nofal Reference Nofal2023). This quality is especially relevant for designing (with) emerging materials with unique temporal behaviour. In such settings, card-based design tools have been shown to support inclusive ideation and shared vocabulary development, helping to bridge considerations of temporal, functional and experiential qualities (Parisi et al. Reference Parisi, McQuillan and Karana2024).

In domains such as synthetic biology and smart materials, co-design workshops have been used to examine how novel systems might be interpreted, maintained or trusted before implementation (Huang et al. Reference Huang, Lin, Chou and Hsu2024; Kim et al. Reference Kim, Zeng, Ellis and Karana2024; Moreira et al. Reference Moreira, Marshall and Staykova2023). For materials that may behave autonomously or appear “alive,” such early dialogue becomes particularly important, as participants must collectively define what acceptable, meaningful or responsible behaviour entails (Elsacker et al. Reference Elsacker, Zhang and Dade-Robertson2023; Kim et al. Reference Kim, Risseeuw, Groutars and Karana2023). Building on this body of work, the workshop presented in this study engages multidisciplinary teams in collaboratively developing applications and expressive self-healing processes for an emerging ELM. The aim is not only to generate concepts but to facilitate shared articulation of material behaviour and its broader implications before technical pathways are fixed.

Workshop context and aims

The co-design workshop was designed to explore how multidisciplinary teams engage with the design of an emerging self-healing ELM, in particular, how they conceptualise the application and expressive behaviour of a self-healing ELM, while also reflecting on its societal implications. The participants were recruited from two research consortia, NextSkins (2026) and FUNGATERIA (2026), which develop ELMs under the EU’s EIC-Pathfinder Challenge funding scheme. Twenty participants were invited from these consortia to reflect a range of disciplinary perspectives, including biodesign, bio-nanoscience, material science and engineering. Approximately half of the participants had prior knowledge or work experience with the self-healing BMBC (Yu et al. Reference Yu, Spiesz, Balasubramanian, Schmieden, Meyer and Aubin-Tam2021), which we used in the workshop. Prior to the workshop, a BMBC ELM material expert provided an introduction to this specific material, explaining its fabrication, properties and current and future capabilities. Furthermore, participants were able to touch and feel samples of the BMBC material. After that, participants were randomly assigned to six groups of three to four participants, ensuring that the backgrounds and two project consortia were mixed. The workshop was structured in three sequential phases: (1) concept development, (2) self-healing process design and (3) a group discussion on broader implications, to explore answers for the following research questions:

• • What future concepts are developers of self-healing materials envisioning?

• • What underlying motivations shape their imaginaries?

• • What concerns and opportunities do they foresee for self-healing ELMs?

BMBC material and self-healing capabilities

The material used as a case in this study was an ELM currently under development in the EIC-Pathfinder research project NextSkins (2026). The base material, known as Biomineralised Bacterial Cellulose (BMBC), is a bio-composite inspired by nacre (Yu et al. Reference Yu, Spiesz, Balasubramanian, Schmieden, Meyer and Aubin-Tam2021). It consists of biologically produced bacterial cellulose reinforced with calcium carbonate minerals through microbial activity. Based on the work of Yu et al. (Reference Yu, Spiesz, Balasubramanian, Schmieden, Meyer and Aubin-Tam2021), BMBC is strong, lightweight, impact- and fire-resistant and demonstrates high compressibility. It can be moulded, is biodegradable and is recyclable. In this study, self-healing was explored as a speculative extension of this material. The envisioned capability draws on microbial biomineralisation, a process in which microorganisms produce minerals that can strengthen or repair material structures, discussed as a promising pathway for regenerative and self-healing material futures (Vekemans et al. Reference Vekemans, Parisi, Martins, Wu, Aubin-Tam and Karana2024). For example, dormant bacterial spores could be embedded within the material structure and activated by environmental triggers such as moisture or pH, initiating local mineral formation at damaged areas. While such self-healing behaviour is not demonstrated in the current BMBC material as described by (Yu et al. Reference Yu, Spiesz, Balasubramanian, Schmieden, Meyer and Aubin-Tam2021), this envisioned capability served as a design case for the workshop.

Workshop procedure

Phase 1: concept development

This phase consisted of three rounds of ideation, in which groups generated and refined design concepts for the self-healing ELM. The first round lasted 8–10 minutes to familiarise participants with rapid brainstorming, followed by two shorter rounds of 5–7 minutes. Each round concluded with a concept, resulting in three distinct concepts per group by the end of the phase. After all three rounds, each group selected one of their three concepts and presented it in a short pitch to the plenary before further developing it in the following phase. In each round, participants received three design cards: a context card, a brainstorm card and an inspiration card. These cards were intended to provoke cross-domain associations and guide divergent thinking. A structured brainstorming canvas supported documentation of ideas, card selections and concept outcomes. For each round, one card from each of the three sets was randomly distributed to each group, allowing for diverse and unpredictable combinations (see Figure 1 for an impression of the co-design workshop during this phase). In the first two rounds, participants used general “What if?” brainstorm cards to stimulate divergent thinking. In the third round, these were replaced by a set of cards informed by the pillars of Living Artefacts for Regenerative Ecologies (Karana et al. Reference Karana, McQuillan, Rognoli and Giaccardi2023), to encourage participants to shift from object-scale functionality towards regenerative and ecosystem-oriented considerations.

Figure 1.

Impression of the co-design workshop, groups brainstorming about application concepts.

Probes in the co-design workshop

Since not all participants were trained in iterative design or creative brainstorming methods, the workshop incorporated structured probes to support inclusivity, stimulate imagination and facilitate shared understanding across disciplines. Four types of cards were developed: context cards, inspiration cards, brainstorm cards and emotion cards. The design of these probes was informed by literature on co-design, speculative design and design fiction, which use structured prompts to provoke cross-domain associations and challenge existing assumptions (Halskov and Dalsgård Reference Halskov and Dalsgård2006; IDEO 2015; Peters et al. Reference Peters, Loke and Ahmadpour2021; Roy and Warren Reference Roy and Warren2019).

The context cards introduced broad, material-relevant application domains in which materials are intensively used, exposed or embedded in everyday life and infrastructure. The selected domains spanned indoor and outdoor settings, ranging from personal-scale applications (e.g., wearables) to infrastructural contexts (e.g., mobility and transportation) and extreme environments, and were intentionally broad and not exhaustive to stimulate diverse interpretations across personal, societal and ecological scales. Inspiration cards were curated across three domains: nature, science fiction and materials science, each including a short description and visual example to support both functional reasoning and imaginative envisioning. The brainstorm cards consisted of open-ended “What if?” prompts designed to stimulate divergent thinking (Board of Innovation 2026; Peters et al. Reference Peters, Loke and Ahmadpour2021). The eleven prompts used in the first two rounds addressed experiential, configurational and economic dimensions (e.g., surprise, sharing, rental models). In the third ideation round, five prompts informed by the Living Artefacts for Regenerative Ecologies framework (Karana et al. Reference Karana, McQuillan, Rognoli and Giaccardi2023), intentionally shifted the focus from product-level functionality to ecosystem-level, relational and regenerative thinking.

The emotion cards were derived from two complementary affect classification models (Barrett and Russell Reference Barrett and Russell2014; Desmet Reference Desmet2018), combining dimensional accounts of affect (e.g., valence and arousal) with discrete emotion categories (e.g., joy, pride), thereby offering both structured and interpretable emotional framings. Some overlap between categories was intentionally retained to allow interpretative flexibility and enable different groups to explore related affective qualities from distinct angles. The probes were iteratively refined through collaborative discussions among the authors and piloted in a rehearsal session prior to the workshop to assess clarity, timing and usability.

In addition to the cards, a structured A3 brainstorming canvas was developed to scaffold documentation and iterative concept development, supporting visual and verbal articulation across disciplines (Medeiros Leopoldino et al. Reference Medeiros Leopoldino, Aguirre González, de Oliveira Ferreira, de Melo and de Vasconcelos2017). To guide the detailed articulation of self-healing processes, participants used the X_Heal Toolkit, developed in prior design research as a structured framework for analysing and characterising dynamic, temporal self-healing behaviours in living materials (Vekemans et al. Reference Vekemans, Parisi, Zeng, Wu and Karana2025). Before engaging with the toolkit, participants received a brief introduction to its underlying taxonomy and an example application to ensure shared understanding of key variables such as colour, texture, hardness, dimensional change and temporal dynamics. This enabled participants to specify perceptible transformations and healing trajectories in a systematic and comparable manner. An overview of all materials is provided in Table 1. Representative visual examples of the probes are included in Appendix A, and the full set of brainstorm prompts is listed in Appendix B.

Table 1.

Overview of design probes and materials used in the co-design workshop

Table 1. Long description

The table presents seven design probes used throughout the workshop together with visual examples, composition, examples, role, and workshop phase. Visual examples include digital context cards showing application domains, inspiration cards combining images and short descriptions, brainstorm cards containing “What if?” prompts, emotion cards with a sketch of the emotion and the word, a structured brainstorming canvas with spaces for card identifiers, sketches and concept descriptions, and the X_Heal annotation template used to map self-healing processes over time through variables such as colour, texture, dimensional change, direction, and speed. The table explains how each probe supported ideation, reflection, or specification of self-healing behaviours during different workshop phases.

Data collection and analysis

The collected workshop data included brainstorming canvases, X_Heal Toolkit annotation templates, concept sketches and descriptions, as well as transcriptions of team pitches and the final plenary discussion. Figure 2 provides representative examples of completed brainstorming canvases from Round 1 of the workshop, illustrating how participants documented ideas, card combinations and emerging concepts. Figure 3 presents two completed X_Heal Toolkit annotation templates, demonstrating how temporal changes and material variables were specified during the self-healing design phase. Together, these materials comprised visual and verbal representations of participant thinking. A two-part thematic analysis (Braun and Clarke Reference Braun and Clarke2006) was conducted to examine (1) the design modes and orientations that emerged during the workshop and (2) the reasoning participants used about the future implications of self-healing ELMs.

Figure 2.

Two filled-in Brainstorming Canvases of two different groups during the co-design workshop, round 1.

Figure 2. Long description

The figure shows two completed A3 brainstorming canvases from different workshop groups. Each canvas contains fields for context, inspiration, and brainstorm card identifiers, spaces for sketching and note-taking, and a section for describing a final concept. Handwritten annotations, sketches, keywords, and concept descriptions illustrate how participants documented and developed ideas during the first ideation round. The examples demonstrate the use of the canvas to structure brainstorming, combine prompts, and record emerging application concepts for self-healing materials.

Figure 3.

Two completed X_Heal Annotation Templates from two different groups during the co-design workshop, phase 2.

Figure 3. Long description

The figure presents two completed X_Heal Annotation Templates produced by different workshop groups during Phase 2 of the co-design workshop. Each template is organised around a timeline of a self-healing process and includes fields for describing the type of damage, healing direction, duration, and changes in material properties. Participants documented transformations in variables such as colour, texture, hardness, dimension, and form, together with sketches representing different stages of the healing process. The completed examples illustrate how the template was used to systematically describe and communicate dynamic self-healing behaviours, making temporal and perceptible material changes explicit during concept development.