Lemmy — smart companion robot for the elderly

Context

Lemmy is a social companion robot for older adults who live independently at home. It was developed in the national R&D project “Commercialization design and development of Intelligent Product-Service System for personalized full silver life cycle care” (MOTIE/KEIT, task 20015056) by a consortium of UNIST, the manufacturer Shinsung Delta Tech and the design firm J Design Works. Besides the robot, the system includes a sensing pot that collects everyday data, an assistant caregiver device and an app for family members and caregivers.

Challenge

Care robots for daily living were mostly technology-driven, with little design input and no systems view. The team had to turn the needs of people in their 60s to 80s into behaviours a robot could actually perform, and then into requirements that engineers in three organisations could build against.

My role

• Specification development (lead). I led the translation of user scenarios into functions, components and engineering specifications, applying and refining the method that became my PhD research, and compiled the functions-and-components list for the prioritised scenarios (2023).
• User scenarios. Together with Bertha Barrera Garza I wrote the English scenario book (2022) that defines how Lemmy behaves. I tested the scenarios with older adults and experts and helped design the Kano-based evaluation used to prioritise them.
• Robot character. I contributed to the personas, the robot's personality, its size and form, and the expression catalogue — including the robot's voice (2025).

Process

From research to scenarios. The team interviewed six domain experts, held focus groups with 12 older adults and visited 15 households to interview 16 older adults at home. This research, together with internal and external workshops, led to 47 scenarios grouped under seven need areas, from sleeping and medication to entertainment and social life. Each scenario pairs what the user does with how Lemmy responds — on screen, in sound and in movement. After expert and user validation they were narrowed to 15 priority scenarios, and a Kano-based evaluation sorted the functions into must-be (for example, emergency detection and medication reminders), attractive and questionable ones.

From scenarios to specifications. Each scenario was broken into action steps, then into design requirements, functional components and target values, so that designers and engineers worked from one traceable chain instead of separate documents. The approach was first tested with the project's 28-person design and engineering team and was later published as the Scenario-Oriented Specification (SOS) method; the scenario-to-specification method became one of the project's design guides.

Size, form and character. Full-scale foam mock-ups of different sizes were compared in six households to settle Lemmy's size, and I took part in these size and form studies. The exterior was narrowed from 14 proposals to 7, then to 2 candidates and the final design, developed with J Design Works and Shinsung Delta Tech. In parallel, three personality concepts were sketched for different groups of users.

Expression. With the design team I worked on the expression catalogue: 23 emotions, each defined across the face on the display, movement, LED light, voice and sound, and tied to a line from a scenario. Besides basic emotions, it includes states a care robot needs, such as lonely, concerned, attentive and relieved.

Voice. I benchmarked the voices of commercial companion robots and found that voice type follows a robot's size and role. For a mobile robot that older adults must understand easily, I chose a humanoid-leaning voice with a subtle synthetic identity, then produced a voice expression for each emotion in the catalogue with Typecast and documented the process.

Deliverables

• English scenario book and the prioritised scenario set
• Scenario-to-specification method and the functions-and-components list
• Voice expression set and its documentation for the expression catalogue