Plant-Inspired Robot Design Metaphors for Ambient HRI

Authors: Victor Nikhil Antony, Adithya R N, Sarah Derrick, Zhili Gong, Peter M. Donley, Chien-Ming Huang · HRI 2026

Licences

Open Access
Paper: CC BY 4.0

Everything below draws on the full paper under its CC BY 4.0 licence; its figure is credited to the authors.

TL;DR

A research-through-design study that builds plant-like robot leaves, stems and pots, combines them into four prototypes, and draws design considerations from workshops with 11 people.

Why it matters

The paper gives mechanism-level detail for slow, quiet, soft actuated forms suited to robots at home or on a desk, including what failed, such as noisy and jittery servos. Its design considerations on presence, expressive palette, timing and shape apply to any robot meant to stay in the background.

Problem

Most HRI design draws on human and animal models, which tend to produce overt, attention-demanding interaction whatever the robot's role. Plants offer a different model, a low-demand presence that still shapes routines through slow rhythms and subtle gestures, but earlier plant-inspired robotics covered isolated functions or materials rather than how plant metaphors could reshape HRI as a whole.

Proposed solution

Through iterative prototyping the authors built four primitives: a 3D-printed TPU leaf that curls and straightens as a string through its spine is tensioned, a stem of concentric TPU and PET-G bellows bent by rack-and-pinion, rotating or mobile pots, and LED flowers, driven by stepper motors with TMC drivers. They combined these into four prototypes (Snake Plant, Flower Plant, Keeper Plant, Dancing Pot), showed a storyboard scenario for each in three 90-minute workshops with 11 participants, and turned the results into design considerations.

Key insights

Servo motors were too noisy and jittery for ambient expression; stepper motors with TMC drivers and microstepping gave near-silent, fine-resolution motion.
Plant gestures are open to interpretation: the Keeper Plant's pulsing read as a gentle reminder to some participants and as inexplicable to others.
Subtle gestures can go unnoticed: the Keeper Plant's slow unfurling was easy to miss unless seen up close, a concern for medication reminders, while the Snake Plant's flutter and the Dancing Pot's swaying were well received.
Mixing plant gestures with human-like cues helped: the Snake Plant's pulsing leaves read as a celebratory 'clap' that participants enjoyed.
Participants valued non-reactivity: one said a plant-like robot would be easier to talk to than a robot with a face because it would not frown at them.

Main results

Four prototypes built from the primitives: Snake Plant (three actuated leaves on a rotating, angled pot), Flower Plant (actuated stem, flower and passive leaves on a rotating pot), Keeper Plant (four actuated and four passive leaves around a cavity, with a light sensor) and Dancing Pot (mobile pot with a two-tier leaf crown).
Three 90-minute workshops with 11 participants aged 19–82 (M = 39.7, SD = 24.8), one made up entirely of older adults, produced an annotated portfolio for each prototype.
Participants were critical of the Flower Plant steering conversation (pointing at snacks felt 'awkward' and 'pushy') and moved social mediation toward classrooms, family mood plants and paired 'twin' plants for long-distance relationships.
Participants extended the Snake Plant posture nudge to wider wellbeing cues and proposed a flower-shaped video-call camera that closes for privacy, a dimming lamp for sleep routines, and habit-tracking plant gardens.
Workshop ideas led the authors to build two more non-literal prototypes afterwards: a plant-inspired lamp and a robotic bookmark.
The findings were organised into design considerations on four axes: Presence, Palette, Rhythms and Shape.

Limitations

The prototypes are speculative probes, not fully functional systems, and the flower primitive was explored only to a limited extent.
Actuation noise, torque, motion granularity, heat management and power limited form and gestures, and multi-material manufacturing made aesthetic quality hard to reach.
Robotic plants carry a large ecological footprint and could displace real plants, which the authors raise as a direction for future work.
The prototypes used only low-fidelity sensing such as light and touch, while many imagined uses need richer awareness of context.
Eleven workshop participants, and the micro-interaction design phase was skipped in Workshop #3 for lack of time.

Field impact

Honourable mention for the HRI 2026 Best Paper Award (Design track, full papers), with 1 citation. The authors release the robotic plant prototypes as open source through a materials link given in the paper.

Abstract

Plants offer a paradoxical model for interaction: they are ambient, low-demand presences that nonetheless shape atmosphere, routines, and relationships through temporal rhythms and subtle expressions. In contrast, most human–robot interaction (HRI) has been grounded in anthropomorphic and zoomorphic paradigms, producing overt, high-demand forms of engagement. Using a Research through Design (RtD) methodology, we explore plants as metaphoric inspiration for HRI; we conducted iterative cycles of ideation, prototyping, and reflection to investigate what design primitives emerge from plant metaphors and morphologies, and how these primitives can be combined into expressive robotic forms. We present a suite of speculative, open-source prototypes that help probe plant-inspired presence, temporality, form, and gestures. We deepened our learnings from design and prototyping through prototype-centered workshops that explored people’s perceptions and imaginaries of plant-inspired robots. This work contributes: (1) Set of plant-inspired robotic artifacts; (2) Designerly insights on how people perceive plant-inspired robots; and (3) Design consideration to inform how to use plant metaphors to reshape HRI.

Open Source Robotics