EX-TEM

Temi is a commercially available service robot used in healthcare, hospitality, and accessibility contexts. Its existing capabilities include navigation, voice interaction, and video communication — but it lacks the ability to physically interact with objects, severely limiting its usefulness for people with mobility impairments.

Fundación ONCE identified this gap and partnered with UDIT to challenge students to design a gripping attachment that could extend Temi's capabilities without modifying its core structure. The attachment had to be non-invasive, reversible, and manufacturable with accessible technology.

The user research phase involved direct contact with people with different mobility conditions — from reduced hand dexterity to full wheelchair users. Their feedback shaped every design decision: handle size, grip force range, interaction interface, and the scenarios the system needed to support (picking up fallen objects, delivering medication, carrying light bags).

This human-centered approach was not just a methodological choice — it was the entire foundation of EX-TEM. The design only succeeded when tested by the people it was meant to serve.

The gripper mechanism was designed in Rhinoceros using a parametric approach that allowed rapid iteration on jaw geometry, finger count, and travel range. Three different configurations were modeled before settling on a two-finger adaptive grip that could handle objects from a 30mm cylinder to a 180mm wide flat surface.

The mounting interface was designed as a universal clamp that attaches to Temi's existing arm socket without tools — a snap-fit and quarter-turn lock mechanism that can be installed or removed in under 20 seconds.

All structural components were 3D printed using Raise3D and BambuLab X1C Carbon printers in PETG-CF (carbon fibre reinforced PETG) for maximum stiffness-to-weight ratio. The final prototype weighs 340g — well within Temi's arm payload capacity.

Keyshot Studio was used to produce the final presentation renders, showcasing both the technical detail of the mechanism and the human interaction scenarios — demonstrating the system in the context of its actual use.

The first prototype was functional, tested, and validated with real users from Fundación ONCE. The feedback was overwhelmingly positive — particularly regarding the ease of object retrieval in seated positions and the intuitive interaction model.

Key learnings: grip force calibration required more granularity than originally anticipated; a soft-touch outer coating significantly improved user confidence; and a status LED feedback system proved essential for user orientation.

A second iteration has been scoped, incorporating the user feedback: improved tactile coating, a refined force-feedback control loop, and a wider object compatibility envelope. The collaboration with Fundación ONCE remains open for continued development.

EX-TEM represents the kind of design work that matters most — not a concept, but a physical object that genuinely changed the experience of the people who used it.