Floating Companion: Exploring Design Space for Soft Floating Robots in Indoor Environments | Proceedings of the 2026 Designing Interactive Systems Conference

AbstractAbstractSoft floating robots (SFRs) represent a shift from rigid machines, offering gravity-defying, compliant, and tactile embodiments for indoor cohabitation. However, their development remains fragmented across isolated prototypes, lacking a coherent design vocabulary. Without a systematic understanding of their interactional capabilities, designers struggle to leverage SFRs’ unique affordances, and these systems often remain limited to novelty applications that are difficult to integrate into everyday life. To address this, we propose a design space for interaction with SFRs. Informed by an exploratory study with 12 experts from HCI, Design, and Robotics, we identify ten design dimensions spanning physical, interactive, and behavioral properties, along with a range of application scenarios. We further present proof-of-concept design examples to demonstrate how this design space can support diverse interaction possibilities. This work contributes a structured framework for understanding and designing interactions with SFRs, supporting their integration into everyday indoor environments.AI Summary AI-Generated Summary (Experimental)This summary was generated using automated tools and was not authored or reviewed by the article's author(s). It is provided to support discovery, help readers assess relevance, and assist readers from adjacent research areas in understanding the work. It is intended to complement the author-supplied abstract, which remains the primary summary of the paper. The full article remains the authoritative version of record. Click here to learn more.Click here to comment on the accuracy, clarity, and usefulness of this summary. Doing so will help inform refinements and future regenerated versions. To view this AI-generated plain language summary, you must have Premium access.Figure 1:We explore how soft floating robots (SFRs) can integrate into indoor environments through varied relational, assistive, and atmospheric interactions. Illustrated here are different SFR forms supporting users in daily life (left to right): (1) a fish-like SFR exhibits lifelike swimming motions, circling around the user and offering gentle, calming touch that evokes the tranquility of an underwater world for emotional support; (2) a balloon-shaped SFR follows and orbits the user, providing on-demand assistance while freely navigating across floors and varied terrain; (3) a jellyfish-inspired SFR uses pulsating rhythms as visual cues for breathing, guiding meditation and fitness through embodied

tempo; (4) an agile omnidirectional SFR enables remote interaction with pets at home, supporting playful engagement when the owner is away; (5) a cloud-like SFR gently approaches to deliver reminders, such as upcoming schedules or prompts to take a break after prolonged desk work.1 IntroductionFrom the mischievous glow of Tinker Bell1, the gentle drift of Ghibli’s Soot Sprites2, and the loyal companionship of airborne pets like Pokémon’s Drifloon3 and Mew4, popular culture has long imagined gentle, floating beings that share our living spaces. In fantasy role-playing games, such as Dungeons & Dragons5, these entities often act as extensions of the player, enriching perception and experience. Such visions reflect a persistent human desire for gentle, floating presences that are soft, ethereal, and untethered from the ground, cohabiting our full three-dimensional (3D) spatial environment rather than remaining bound to surfaces.Recent developments in lighter-than-air soft floating robots (SFRs) bring us closer to this possibility. Defined as lighter-than-air robots with soft helium-filled envelopes, SFRs combine buoyancy-based 3D mobility, soft compliance, and relatively quiet operation [70, 113], making them promising for close-proximity indoor interaction under appropriate safety constraints [57, 105, 112].Prior work on SFRs reveals several unique material and interactional qualities: (1) Safety through compliance: Their soft, lighter-than-air construction enables lower-risk gentle contact and operation above people [105, 112], unlike rotor-based drones; (2) Quiet and gentle 3D mobility: They utilize mid-air space for spatial interaction without downwash or noise of drones [70, 113]; (3) Customizable form: their inflatable bodies support diverse morphologies, from marine animals [13, 30, 31, 111, 112] to clouds [94, 117], humanoid silhouettes [24], and geometric shapes [42, 66, 113]. In summary, SFRs hold significant potential to enrich our physical environments with embodied spatial experiences.

We envision a future in which floating companions drift through indoor spaces, taking on companionship-oriented, assistive, and ambient roles that enhance daily life. In this paper, we use the term Floating Companion to describe one relational orientation in which soft floating robots support nearby co-presence and interaction in shared indoor environments. This is not intended as a label for all SFR applications; rather, the broader design space also includes assistive and atmosphere-based roles. In that sense, we use the term companion to describe entities that engage in ongoing, non-hierarchical co-presence with users, encompassing emotional, ambient, and assistive interactions beyond purely instrumental use. By embracing human imagination, SFRs can open new avenues for ubiquitous computing, aligning with a broader shift toward adaptable, seamlessly integrated robotic systems [17, 35, 92].Yet, despite promising progress, we lack a coherent design vocabulary for this emerging morphology. Most studies investigate single prototypes or narrow scenarios, offering limited guidance for designing interactions more broadly. As a result, we lack a systematic understanding of how SFRs can move, behave, and interact with humans across diverse contexts. There is currently no unified design space that articulates the interactive possibilities afforded by SFRs, leaving designers without actionable guidance for developing interactions with soft floating robots.To address this gap, we move beyond singular prototypes and present a design space that maps the interactive possibilities of this emerging class of robots. Our goal is to establish a foundational framework that can inform future research and design. We explore how SFRs might support a broader range of activities in everyday indoor environments and how their unique 3D mobility can extend their usefulness beyond functional tasks. As floors, tables, and other surfaces become increasingly saturated with smart devices, the volumetric mid-air space remains an underutilized interaction space—one that SFRs are uniquely positioned to occupy. Leveraging this spatial layer offers new opportunities for SFRs to provide meaningful support in people’s daily lives.While prior work has introduced diverse SFR prototypes, the field lacks a unified framework to guide their interaction design. This study addresses this gap by moving beyond isolated examples to establish a structured foundation for interaction with SFRs.

Our study explores the following research questions:RQ1:What is the design space for creating interactions with soft floating robots?RQ2:What roles and functions might soft floating robots fulfill in everyday indoor environments?To answer these questions, we conducted an exploratory study with 12 experts from HCI, HRI, Design, and Robotics. Through thematic analysis of the interview data and informed by existing literature, we derived a ten-dimensional design space describing how SFRs can move, behave, and engage with humans and environments (Sec. 4). The study also yielded a rich set of application use cases, expanding the known functionalities of these robots (Sec. 5). Then, we ground these possibilities in engineering reality through a Physics-Design Dependency Framework (Sec. 6.1), synthesizing actionable design principles (Sec. 6.2). Finally, to demonstrate the generative power and technical feasibility of the design space, we implemented proof-of-concept demonstrations that instantiate design dimensions and principles (Sec. 7). Collectively, our approach highlights how SFRs can be leveraged to enhance and support contemporary lifestyles.In summary, this work establishes a foundational framework for SFR interaction through four key contributions:(1)A 10-dimensional design space for creating interactions with SFRs, derived from an expert study—to our knowledge, the first systematic framework for SFR interaction design.(2)A diverse set of application cases that illustrate the range of SFR roles, spanning presence-based, function-based, and atmosphere-based scenarios.(3)Three core design principles distilled from the design dimensions. Grounded in the physics-design entanglement of lighter-than-air bodies, these principles provide actionable guidance for navigating trade-offs and leveraging SFRs’ unique qualities.(4)Proof-of-concept design examples implemented on a representative flapping-wing platform, illustrating how the principles can be instantiated to enable novel SFR interactions.2 Related Work2.1 Soft Floating Robots: Embodiments and ActuationOur work builds on the growing interest in materiality within HCI. Researchers have explored soft interfaces [14, 83, 95] to support physical and emotional interactions.

In parallel, a substantial body of work has investigated flying robots designed to interact with people in human-drone interaction (HDI) [9, 46, 53, 61, 77, 93, 106], conceptualizing them as flying companions that could enter everyday life [38, 40, 58]. However, most of this research has focused on rigid, propeller-driven drones. In contrast, soft floating robots (SFRs) extend this line of inquiry into mid-air by combining softness and buoyancy, thereby liberating soft interfaces from ground-based constraints and opening new possibilities for aerial interaction.Figure 2:Actuation taxonomy of soft floating robots (SFRs). Based on propulsion mechanisms, SFRs can be broadly categorized into vectored-thrust propulsion and bio-inspired propulsion. Vectored-thrust systems rely on controlled force generation, typically using propellers or equivalent mechanisms: gondola-type propeller-driven SFR (e.g., [115]), omnidirectional multi-propeller array SFR (e.g., [34]), external-mounted propeller SFR (e.g., [18]), shrouded propeller SFR (e.g., [50]), and propeller-free SFR using alternative thrust mechanisms (e.g., [113]). Bio-inspired systems emulate biological motion patterns, such as flapping or oscillation: multi-wing flapping SFR (e.g., [81]), two-wing flapping SFR (e.g., [30]), tail-fin oscillation SFR (e.g., [25, 64]), and jellyfish-like peristaltic SFR (e.g., [32]).Our research focuses on soft floating robots. For this study, we define a soft floating robot (SFR) as an untethered, autonomous, or semi-autonomous agent that can typically hover in the air without active power. An SFR satisfies three core conditions:(1)Its primary interactive surface is soft and compliant.(2)It possesses controlled actuation and sensing, enabling mobility and interaction.(3)It is lighter-than-air, generating lift primarily through static buoyancy (e.g., helium).This definition explicitly distinguishes SFRs from heavier-than-air soft drones (e.g., [44, 107]).