The Kiri-Spoon: Research turns robotic hardware into flatware for assisted eating TechTricks365

More than 2 million adults living in the United States rely on a caregiver’s assistance to eat daily meals. In addition to human caregivers, technology has been developed to provide assistance. For example, tabletop and wheelchair-mounted robotic arms have been programmed to pick up foods and bring them to the human operator.

Assistant Professor Dylan Losey brought a team together with backgrounds in both assistive robotics and computer science to explore new technological possibilities for those with limited mobility. Their study on an origami-inspired tool was published on the arXiv preprint server after a successful human trial. The Kiri-Spoon, from “kirigami,” the Japanese art form of cutting paper, can both grasp like a fork and scoop like a spoon.

“Existing systems for robot-assisted feeding use standard forks and spoons, but robots struggle to dexterously manipulate these utensils and consistently deliver food from plate to mouth,” said Losey. “We wanted to create a new utensil that gave the robot a mechanical advantage, something that would make it easier for robots to pick up, hold, and deliver food.

“In parallel, we needed algorithmic intelligence that could carefully control the robot and manipulate the utensil. Most importantly, our solution needed to be a system that people actually liked to use.”

New tools for helpful robots

Losey has an extensive background in assistive robotics, leading projects that use artificial intelligence and machine learning to adapt the software of mechanical helpers for a variety of tasks. For this project, his team applied that robotic intelligence to physical tools, ultimately combining computer hardware with new, innovative mechanical flatware.

“When we started this project, the team knew that the best solution would combine both hardware and software improvements,” Losey said. “Good engineering solutions should have both.”

For this reason, Losey’s team collaborated with Tapomayukh Bhattacharjee’s team at Cornell. The students in Losey’s lab led the mechanical development of the utensil, and the Cornell team provided the code that told the robot how to move the utensil.

“We spent a lot of time brainstorming,” said student first author Maya Keely. “We wanted something that could give a normal spoon look, so that it would be comfortable and familiar to the users. But we also knew that robots struggle to use basic forks and spoons, so we needed something that would robustly hold food, even if the robot tilts, moves quickly, or changes direction. After a lot of trial and error, we ended up with our kirigami design.”

The Kiri-Spoon is composed of a flat, 3D printed plastic similar in thickness to a sheet of paper. By itself, it looks like a standard spoon. When both ends of the kirigami sheet are extended, the 2D sheet becomes a 3D bowl that pinches and encloses food; when delivering that food to the user, the sheet retracts to a normal spoon shape, with the robot controlling its extension.

Striving for comfort

“Engineering is really only half of the story,” Losey said. “This is supposed to be an assistive system for people who can’t eat on their own. To come up with an effective solution, we needed to work with actual users and see what they really needed.”

Keely, Franco, and Grothoff took the prototype to The Virginia Home in Richmond, a center for residents with irreversible physical disabilities.

“Conducting user studies and discussing our ideas with Virginia Home residents was really eye-opening,” said Keely. “We had solutions that seemed great from an engineering perspective, but when users tried them out, they completely failed. The feedback from users and caregivers really guided our process.”

While the robot was able to wield the utensil and deliver food, residents told researchers that the metal ring that supported the kirigami sheet was not very comfortable.

“It was obvious when they pointed it out. But it’s not something we would have thought of on our own,” said Grothoff.

Team members went back to the lab. They changed the metal hoop for a nickel titanium wire that was coated with food-safe plastic. This wire allowed for additional flexibility, making it a better design than the original, and the second round of testing was a success.

“Our new Kiri-Spoon design is more comfortable and functional, but it will still take time for people to eat using this technology,” said Nemlekar. “Eating is an integral part of daily life, and we hope that our efforts can make this process more seamless for people with disabilities and make a difference in their everyday lives.”