A Pivot-Based Kirigami Utensil for Hand-Held and Robot-Assisted Feeding

TL;DR

This paper introduces a pivot-based kirigami utensil adaptable for both hand-held and robot-assisted feeding, improving food security and usability for individuals with mobility challenges through a simple, customizable design.

Contribution

The paper presents a novel, reconfigurable kirigami utensil that functions as both a spoon and fork, designed for accessibility and robot integration, with a focus on user-centered design.

Findings

Users preferred the kiri-spoon over existing utensils for spill prevention.

The design is highly accessible, requiring only four 3D printed parts.

The utensil's force characteristics can be customized through design modifications.

Abstract

Eating is a daily challenge for over 60 million adults with essential tremors and other mobility limitations. For these users, traditional utensils like forks or spoons are difficult to manipulate -- resulting in accidental spills and restricting the types of food that can be consumed. Prior work has developed rigid, hand-held utensils that often fail to secure food, as well as soft, shape-changing utensils made strictly for robot-assisted feeding. To assist a broader range of users, we introduce a re-designed kiri-spoon that can be leveraged as either a hand-held utensil or a robot-mounted attachment. Our key idea -- developed in collaboration with stakeholders -- is a pivot-based design. With this design the kiri-spoon behaves like a pair of pliers: users squeeze the handles to change the shape of the utensil and enclose food morsels. In practice, users can apply this kiri-spoon as either a spoon (that scoops food) or as a fork (that pinches food); when the handles are closed, the utensil wraps around the morsel and prevents it from accidentally falling. We characterize the amount of force required to open or close the kiri-spoon, and show how designers can modify this force through kinematic or material changes. A highlight of our design is its accessibility: the hand-held version consists of just four 3D printed parts that snap together. By adding a servo motor, we can extend this same kinematic structure to robot-assisted feeding. Across our user studies, adults with disabilities and elderly adults with Parkinson's reported that the kiri-spoon better met their needs and provided a more effective means of spill prevention than existing alternatives. See a video of our kiri-spoon here: https://youtu.be/FFIomm5RL98