Bio-digital systems that merge microbial life with technology promise new modes of computation, combining biological adaptability with digital precision. Yet realizing this potential symbiotically – where biological and digital agents co-adapt and co-process – remains elusive, largely due to the absence of a shared vocabulary bridging biology and computing. Consequently, microbes are often constrained to uni-directional roles, functioning as sensors or actuators rather than as active, computational partners in bio-digital systems. In response, we propose a taxonomy and pathways that articulate and expand the roles of biological and digital entities for synergetic bio-digital computation. Using this taxonomy, we analysed 70 systems across HCI, design, and engineering, identifying how biological mechanisms can be mapped onto computational abstractions. We argue that such mappings enable computationally actionable directions that foster richer and reciprocal relationships in bio-digital systems, supporting regenerative ecologies across time and scale while inspiring new paradigms for computation in HCI.

Food and flavors are integral to our existence in the world. Nonetheless, taste remains an under-explored sense in interaction design. We present Füpop, a technical platform for delivering in-mouth flavors that leverages advances in electronics and molecular gastronomy. Füpop comprises a fully edible pouch placed inside the mouth against a cheek that programmatically releases different flavors when wirelessly triggered by a focused ultrasound transducer from outside the cheek. Füpop does not interfere with activities such as chewing and drinking, and its electronics may be integrated into devices already used near the cheek, such as mobile phones, audio headphones, and head-mounted displays. Füpop’s flavors are from “real foods,” not ones imitated with synthetic reagents, providing authentic, nutritive flavors. We envision that with Füpop, flavors may be synced to music, a phone call, or events in virtual reality to enhance a user’s experience of their food and the world.

Skin-based electronics are an emerging genre of interactive technologies. In this paper, we leverage the natural uses of lotions and propose them as mediators for driving novel, low-power, quasi-bistable, and bio-degradable electrochromic displays on the skin and other surfaces. We detail the design, fabrication, and evaluation of one such “Lotion Interface,” including how it can be customized using low-cost everyday materials and technologies to trigger various visual and temporal effects – some lasting up to fifteen minutes when unpowered. We characterize different fabrication techniques and lotions to demonstrate various visual effects on a variety of skin types and tones. We highlight the safety of our design for humans and the environment. Finally, we report findings from an exploratory user study and present a range of compelling applications for Lotion Interfaces that expand the on-skin and surface interaction landscapes to include the familiar and often habitual practice of applying lotion.

Providing electrical power is essential for nearly all interactive technologies, yet it often remains an afterthought. Some designs handwave power altogether as an “exercise for later.” Others hastily string together batteries to meet the system’s electrical requirements, enclosing them in whatever box fits. Vim is a new approach – it elevates power as a first-class design element; it frees power from being a series of discrete elements, instead catering to exact requirements; it enables power to take on new, flexible forms; it is fabricated using low-cost, accessible materials and technologies; finally, it advances sustainability by being rechargeable, non-toxic, edible, and compostable. Vims are decomposable battery alternatives that rapidly charge and can power small applications for hours. We present Vims, detail their characteristics, offer design guidelines for their fabrication, and explore their use in applications spanning prototyping, fashion, and food, including novel systems that are entirely decomposable and edible.

Sustainability is critical to our planet and thus our designs. Within HCI, there is a tension between the desire to create interactive electronic systems and sustainability. In this paper, we present the design of an interactive system comprising components that are entirely decomposable. We leverage the inherent material properties of natural materials, such as paper, leaf skeletons, and chitosan, along with silver nanowires to create a new system capable of being electrically controlled as a portable heater. This new decomposable system, capable of wirelessly heating to >70°C, is flexible, lightweight, low-cost, and reusable, and it maintains its functionality over long periods of heating and multiple power cycles. We detail its design and present a series of use cases, from enabling a novel resealable packaging system to acting as a catalyst for shape-changing designs and beyond. Finally, we highlight the important decomposable property of the interactive system when it meets end-of-life.

The access and growing ubiquity of digital fabrication has ushered in a celebration of creativity and “making.” However, the focus is often on the resulting static artifact or the creative process and tools to design it. We envision a post-making process that extends past these final static objects — not just in their making but in their “unmaking.” By drawing from artistic movements such as Auto-Destructive Art, intentionally inverting well-established engineering principles of structurally sound designs, and safely misusing unstable materials, we demonstrate an important extension to making — unmaking. In this paper, we provide designers with a new vocabulary of unmaking operations within standard 3D modeling tools. We demonstrate how such designs can be realized using a novel multi-material 3D printing process. Finally, we detail how unmaking allows designs to change over time, is an ally to sustainability and re-usability, and captures themes of “aura,” emotionality, and personalization.