The UX Of A Public Robot

Robots are increasingly cropping up in public spaces. The design studio Ammunition reveals how it devised an automated barista to look friendly–but not too friendly.

Sometimes when you need caffeine, the last thing you want to deal with is an overly cheerful (or overly) grumpy barista. And for the last year, a robot barista called Cafe X has been fulfilling that desire for San Franciscans. It features a robotic arm that can deliver Americanos, caffe lattes, and flat whites to waiting customers in just a few seconds.


But seeing a robotic arm that’s typically used in factories brew a cappuccino for you might be a little unsettling, especially because it can brew a single cup in a little over 13 seconds. You might be just a little nervous around the fast, mechanical motions of the arm as it picks up and drops off cups of coffee right before your eyes. We’re not used to seeing robots so flagrantly out in the open–and it can feel ominous.

So for its next version of the robot, Cafe X partnered with the San Francisco-based design firm Ammunition–which has designed everything from headphones to smart travel mugs–to design some personality into the robotic arm. “We worked to figure out a whole method of choreographing the arm so that people are getting coffee from the machine, but there’s also a novel and surprisingly friendly aspect to it, rather than just a purely robotic machine serving you,” says Ammunition senior UX designer Zack London.

The first version of the robot would wave to customers after they picked up their coffee, and version two will continue to do that as well. The team has also programmed the robot to inspect the coffee containers, which has a dual purpose: doing a double-check on how much coffee is left in each machine, and making the robot seem a little bit more like your average human barista. The robot will also give your cup a swirl–a gesture that’s just fun to watch. Cafe X founder and CEO Henry Hu also wants the robot to acknowledge customers’ presences when they first enter their code into the pick-up station, which is the trigger for the robot to bring them their coffee. It adds another layer of humanlike interaction to the entire experience–and Hu believes people will like it as much as they seem to love the robot’s wave as they leave.

This gif shows a gesture the designers recommended that Cafe X perform.

When the newly designed Cafe X opens for business in San Francisco on February 27, it won’t have all these features yet–instead, the team will roll them out slowly so they don’t unnecessarily slow the robot down, as it takes between 10 to 15 seconds to deliver a single person’s drink and perform a gesture, like a wave. Right now, it can make three drinks in about 40 seconds, and that’s with some of the personality programmed into the robot. But care went into making the robot friendly, not ominous, and earnest, not silly.

[Image: courtesy Ammunition]
The designers knew that regardless of what they did, people were going to anthropomorphize the robot. It’s a human tendency, to see humanity in non-human things–be that animals, robots, or even the faces we see in clouds. It’s something that many robot designers rely on, and has resulted in cutesy home bots like Kuri or Jibo that have faces and almost act like pets. But for London, giving the Cafe X robot a personality didn’t mean literally giving it a face. “We acknowledge that the way it moves you’re going to attribute some personality. It has idiosyncratic twists and turns and bobs. To that effect we wanted to explore how personality could be shown just through the way it moves, be that when it’s idle or when it’s serving coffee or making coffee, and when it’s engaging customers,” he says. “We basically realized that rather than give it googly eyes or give it fur or give it a face or voice, we could achieve that subtle glimmer of personality purely through choreographing arm’s movement.”

The robot wasn’t originally designed to have a personality. It’s a six-axis industrial robot normally used in factories to move small components around or do light assembly. As a result, it was originally designed to move as fast as possible from point A to point B to achieve simple repetitive tasks very quickly. But it was precisely this kind of fast, jerky movement that made the robotic arm feel a little too ominous.


[Image: courtesy Ammunition]
The team focused first on smoothing out the robot’s movements so it doesn’t move quite so fast on its path from point A to B. To do so, Hu and his team programmed a third point, a point C, in between A and B that the robot would be required to stop at first. It was their way of slowing down the robot’s movements and smoothing out its actions slightly. It’s not something you’d be able to notice, but it is meant to give the robot a slightly friendlier appearance.

As the team tested the smoother movements and began adding gestures, they primarily focused on the feedback they’d gotten from Cafe X version one–particularly around the robot’s wave–with no additional user testing. That might be necessary to navigate the fine line between a gimmick and something that feels natural. “We don’t want to end up in situation where 15 people are waiting for their coffee and the robot is doing a dance,” Hu says.

[Photo: courtesy Ammunition]
They decided that the robot will focus almost entirely on serving as many coffees as quickly as possible during the morning and afternoon rush hours–though not compromising on some of the basic gestures that make the bot seem friendlier. But during idle times, the team sees opportunity to have fun and make the robot even more approachable. Over the next year, the team hopes to try out gestures like the robot playing tricks with cups or using a brush to clean its environment. The latter could actually be useful as well. The health department requires that the countertop of the machine be sanitized every four hours. Right now, Cafe X’s team has to pause the robot and do this manually, but eventually Hu hopes that the robot arm will be able to do it on its own.

Ammunition’s efforts to make Cafe X’s robotic arm seem friendly rather than ominous is part of a larger discussion about the role that robots play in our lives. Should they have personalities? Should they have faces? Should they use the same modes of human interaction, like nods and waves, that we’re used to?

Until robots enter our lives in a more mainstream way, it’s hard to say. Is Cafe X merely a glorified vending machine? Or is its robotic arm personality a beacon of where our culture is headed? It’s up to UX designers to ensure a smooth transition to a society where robots are more prevalent.

About the author

Katharine Schwab is an associate editor at Co.Design based in New York who covers technology, design, and culture.