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KojiGotchi

Biodesign Challenge

2025

Binanox

iGEM Leiden

2022

Creative Fields

Biodesign,
Electronics,
Food Fermentation

Responsibilities

Project Management,
Experimental Design,
Creative Direction

Location

Copenhagen, DK

Year

2025


KojiGotchi: Your companion into post-human futures

Keywords

tamagotchi, food fermentation, ethics of care

Collaborators

Team: Rasmus Emil Tofthøj, Tania Safa, Taylor Rayne
Supervisors: Dr. Adrien Rigobello, Dr. Joshua Evans

Featured in

:: Algae Magazine: Issue 03 – Regeneration
:: iGEM 2025 Art & Design Exhibition
:: Cocoon.bio Virtual Exhibition

KojiGotchi is a speculative wearable exploring the ethics of care and co-dependence between humans and microorganisms. Designed as a living artifact housing Aspergillus oryzae (koji), a fungus central to Asian fermentation traditions, the device relies on the wearer’s body heat to sustain life. In return, the user becomes an active host, establishing a demo-version of a reciprocal relationship of care, in which neglect or attention directly determines both the functionality of the device and the organism’s fate.

For the video, we leaned into the 90s aesthetic. In doing so, we not only paid tribute to the core inspiration–the tamagotchi–but also explored the plurality of aesthetic choices, often overlooked in biodesign in favor of clean & neat.


Genesis

If you’ve ever scrolled through dazzling visions of the future, all green and sleek, you might’ve noticed they often propose a profound shift in our relationship with microorganisms and nature at large. Yet, these futures of more-than-human ecologies and symbiotic relationships often feel so distant from our current reality and lived experiences. They can seem unattainable, almost destined to remain on the shelf of theoretical utopianism. So, how do we make those radical ideas less abstract, and more, well, personal?

Our vision for this project was to embrace precisely this challenge: to translate ambitious biodesign concepts into something truly tangible and accessible for everyone. Our muse? The iconic Tamagotchi. This device, widely recognized for fostering care for a digital pet–a bond unconventional to our traditional perceptions–offered a perfect parallel. We envisioned a similar, engaging framework to introduce the living future, designed to guide users in a new kind of care for the microbial world.

Philosophy

Biodesign isn’t just about new materials; it’s a huge shift in how we see our place in the world. We’re moving past the old idea that humans control nature. Instead, we’re looking to life itself as a guide for design. Imagine objects that aren’t just tools, but active partners that can sense, respond, and even design themselves. This is the more-than-human future, where synthetic biology shows us that livingness is a key quality in materials, making us think about how life and technology are deeply connected.

This project emerged from a personal frustration: the difficulty of truly sharing the bio-future’s profound concepts with our own families and friends. The complex narratives surrounding biodesign often create an elitist barrier, preventing wider audiences from engaging with its transformative potential. Our team formed specifically to address this disconnect. We aim to bridge the gap between abstract bio-design principles and tangible, everyday experiences, inviting everyone to understand and participate in this living future.

  • Post-Human

    This concept questions the traditional idea of humans as separate and superior to nature and technology. It suggests a future where our identity is intertwined with non-human life and advanced systems, leading to new ways of being.

  • More-than-Human-Centred Design
    This design idea includes non-human parts like animals, plants, microbes, and smart tech. It’s about designing with everyone and everything, not just humans.
  • Holobiont
    A living unit made of a host (like you) and all its tiny microbes. It shows we’re not just individuals, but complex, linked ecosystems.
  • Designing-with

    This way of designing means working with humans and non-humans, not just for them. It sees us all as connected by materials, ethics, and our very existence.

  • Care
    More than just looking after something, ‘care’ here means a mindful way of acting and relating to devices and living things. It’s about truly listening, noticing, and building connections where everyone relies on each other.
  • Surfaced Livingness

    This is how a living system shows its life in clear ways, like its growth, smell, changes, and actions. It makes the living thing immediately clear and interesting.

  • Autopoiesis

    This term describes a system, like a living cell, that can produce and maintain itself by creating its own components. It highlights life’s unique ability to self-organize and stay alive.

Product Design

We drew inspiration from the cultural phenomenon of the Tamagotchi. This device once introduced us to portable, attention-demanding digital technology, unknowingly preparing us for today’s mobile world. By analogy, we envisioned a similar, engaging device for the bio-futures that so many biodesign projects propose. The KojiGotchi is that living interface, designed to help you interact with microbes. Through an experience built on care, it teaches a mindful, hands-on approach to science, demonstrating mutual interdependence between humans and microorganisms. This isn’t about simple consumption; it’s about shifting from control to co-production with life itself, inviting you into a truly shared, living future.

Why Tamagotchi?

We chose the Tamagotchi as our blueprint because it’s a universally known format that doesn’t trigger any adverse reactions; it’s instantly relatable. More importantly, it’s a powerful tool for practicing caretaking, easing users into the idea of nurturing a living entity. The Tamagotchi framework avoids extreme direct exposure to microbes, instead focusing on gently teaching users about what microbes need and how to provide attentive care for them.

Why Koji?

Koji was chosen for three key reasons. First, its accessibility: rice and koji spores are easily ordered online, and the tangible outcome—fermented food—is incredibly relatable, helping users grasp the transformation. Second, koji’s ideal growth temperature (25-35°C) perfectly matches human body surface temperature, allowing users to practice attentive care by literally engaging in a symbiosis, nurturing it like an actual egg. Lastly, koji’s livingness is distinctly surfaced by its unique aroma, providing immediate, sensory feedback on the success of their caretaking efforts.

Why Digital Interface?

While some radical biodesigners criticize proxy interfaces that mediate human-biology interaction, we believe a step-by-step learning process is essential. Therefore, we designed KojiGotchi to offer partial direct engagement through metabolic symbiosis and smell, but we still provided a digital interface. This interface facilitates the crucial learning process, helping users understand the subtle needs and cues that koji provides, making complex biological interactions approachable and comprehensible.

KojiMoji

With our experiments complete, we identified all the necessary parts for the KojiGotchi. However, sifting through the data, we realized we needed a simpler way for users to understand how well they were caring for their koji. Drawing clear inspiration from the Tamagotchi, we designed our own digital avatar: the KojiMoji. This character reacts to environmental conditions and offers gentle prompts, acting as a digital guide for fermentation. It helps you understand your koji’s needs and build your own sensory fluency. You can interact with the KojiMoji directly on the main page.

20°C
50%
0ppb
400ppm

User studies

To better understand how people connect with biodesign and the microbial world, we conducted a two-part user study: an interactive session and an online survey. The interactive session allowed us to directly observe participants’ sensory responses to koji and their real-time interaction with our KojiGotchi device, giving us invaluable qualitative insights.

The interactive session aimed to deeply understand the public’s sensory responses to koji and observe their direct interaction with our KojiGotchi prototype. Participants were invited to engage with koji samples, which included smelling, touching, and, optionally, tasting. They were also asked questions about their experiences and perceptions.

The online survey aimed to gain a deeper understanding of the public’s perception of fermentation and microbially-powered technologies. It revealed several key insights into people’s comfort, curiosity, knowledge, and concerns.

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    Experiments

    In order to inform our product design and to verify the feasibility of the proposed functionality, a series of experiments were conducted. These were primarily aimed at evaluating the essential and redundant environmental variables for sustaining the growth of koji.

    Throughout the few couple of experimental setups, we tested the proof of concept: is body heat sufficient to sustain the growth of koji? After successfully confirming this hypothesis, we proceeded to test our electronics so as to identify the parts that had to be included in the final prototype to facilitate the most educational and engaging experience for the users.

    • 17_graphs-781174cd

      Color sensor readings for red, green and blue diodes of TCS34725 captured during the green koji on rice growth experiment. Average and standard deviation shown for n=2.
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      Temperature measurements of the probe submerged in rice and suspended in the air throughout the duration of the growth of white koji on rice. Average and standard deviation shown for n=3
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      Experimental setup in the incubator