What’s your favorite feeling in the world?

Besides that one.

Most people want to feel free, high, weightless. That’s what they told Dr. Patrik Künzler, a medical doctor and mechanical enthusiast, as he sought to understand what makes people feel good—and build a way to do it. His solution was one you wouldn’t expect (unless you read the headline to this article).

He built a chair.

The Chair That Makes You Feel Weightless

In 2006, Künzler was working at the MIT Media Lab and trying to answer a simple question: Can we design something using the brain as a starting point? Rather than letting form follow function, Künzler and his team wanted to let form follow emotion.

By conducting a series of student surveys, the team learned two important facts: people love the feeling of weightlessness, and people hate sitting in chairs. “So we said, ‘Can we create a chair that makes you feel like you're flying, like you're weightless?’” Künzler recalled.

Thus was born the Limbic Chair, a chair that makes you feel weightless. Prototyping with plywood, Künzler and his team developed a seat that uses movement and touch to create a sense of weightlessness in the sitter. The Limbic Chair consists of two shells which wrap delicately around each of a seated person’s thighs. The sitter can move each leg independently with six degrees of freedom from the specially balanced shells. There is no backrest.

Drawing upon his medical background, Künzler explained the principles behind the Limbic Chair.

“It's very comfortable because we combined two things, the pelvic and spinal physics,” he said. “When you're standing or walking leisurely, your back gets automatically upright and relaxed. You'll always have what we call micro movements, little movements that you don't even notice. In the Limbic Chair, we have the spinal physics of standing or walking, but at the same time your legs are supported like when you're sitting. We have the advantages of both worlds. It’s as relaxing as sitting, but you are automatically upright and you have the micro movements so your spine can always move a little bit and doesn't get tired.”

The form and physics of the Limbic Chair enable what Künzler calls incentivized movements, where sitters will naturally move their body in ways that make them feel best.

“We designed the shells so that, if you don't focus on sitting, you automatically start moving because of the way they touch you,” he said. “They prod your body into movement. We call those incentivized movements, meaning movements that express happiness or lead to happiness.”

The Limbic Chair: More Than Just a Seat

Künzler and his team started a company, Limbic Life, to sell the Limbic Chair. Their production capacity was limited, but they found many customers who could benefit from the special seat.

“It's actually very good for your back,” Künzler said. “We have health insurance to pay for the chair. We've had cases where a receptionist is 52 years old and can only work 20 or 30 percent because of her back, and after a month [with the Limbic Chair] she can sit again.”

While the health benefits of the Limbic Chair are impressive, Künzler and his team soon realized that the Limbic Chair could be much more than just a seat. The independent shells, with their six degrees of freedom, almost begged to be put to practical use.

“We were playing around and then somebody said, ‘Hey, let's play computer games like this.’ We hacked into a PlayStation and we started through a racing game. We started doing the steering with the chair instead of just moving that little joystick on your controller. The students liked it a lot, and even Marvin Minsky, who was 80 in those days, he liked it,” Künzler recounted. (Minsky, a titan of artificial intelligence research, passed away in 2016.)

The idea was too good to ignore, and the team soon realized that the Limbic Chair could act as an input device for virtually any application. “From an evolution point of view, [it’s] something our body can do better than our hands,” Künzler explained.

Künzler and his team attached sensors to the Limbic Chair and sought to understand how to make it an intuitive controller. They brought in test subjects and observed how the subjects naturally used the chair for movement. Given a VR headset, the subjects were asked to move a helicopter in different directions using the Limbic Chair. For another test, subjects were shown a distant view of the planet Earth and asked to bring it closer to them—in other words, to zoom in.

“We watched how they do it, what was intuitive for people. That was our starting point. We always tried to start with how humans function, what their instinct is,” said Künzler.

This proved an effective technique, as it revealed intuitions on the level of automatic reflexes. If you see a baseball flying at your face, you’ll duck; if you put your hand on a hot stove, you’ll jerk it back. These reactions don’t require any conscious thought. The Limbic Chair can tap into that same programming, according to Künzler.

“That's all dinosaur brain, spinal instincts,” he said. “We tried to go down to that level of the programs that are older than humans, that are really coded in the deeper layers of our brain—hence, the limbic system—and we tried to activate those programs. So, A, they're intuitive. B, they're fast and reliable. C, learning is very, very fast. And D, it does not occupy your brain. You don't have to think about it.”

Limbic Chair VR

The Limbic Life team began fleshing out their new input system. They called the sensor-equipped chair the Limbic Chair VR, pointing towards what they felt would be one of the best use cases of the technology.

“We really believe we can change how people use VR, because right now it's just awkward,” Künzler said.

But VR is only the beginning. Limbic Life developed an application that allows users to fully configure the Limbic Chair input system, which can be wired to the user’s computer or connected with Wi-Fi or a 900MHz receiver dongle. You could set it up so that squeezing your knees together activates the space key, or pushing your left leg down lowers the volume. But it would be much easier to follow the application-specific pre-sets that Limbic Life has designed.

Computer aided design (CAD), for example, is an exciting potential application of the Limbic Chair VR. According to Künzler, CAD users adapted to the chair almost immediately. “We have shown it to engineers, and one of the things people say is it's much more intuitive to learn than a 3D mouse,” he said.

The Limbic Chair VR has dedicated plug-ins for Siemens Solid Edge and Blender, which allow users to configure their settings and turn the chair on or off. “It's important that the users can fine tune, because as you become more proficient, you might want more shortcuts,” Künzler explained. “You might want a faster axle input-output ratio, and so on. It's like using a 3D mouse for the first time.”

Another exciting application of the Limbic Chair VR is in the medical field. It’s an area that Künzler himself knows well, and he’s seen many medical professionals embrace the Limbic Chair.  For doctors, the biggest advantage is that the chair leaves their hands free for other tasks.

“We all need three to five hands,” Künzler joked. “For example, we have a project with radiologists where they zoom through their MRIs and CT scans. In their left hand, they have a dictation device, in their right hand, they have a mouse, and in their third hand, they have a keyboard. With the chair we give them the zooming, and the panning, and the rotating. They love it because their hands can relax and it's good for their backs. Everybody in the medical world is completely overworked, so it's a great relief for them.”

Limbic Life is working to develop an ecosystem of apps for doctors, engineers and gamers that are specially designed to take advantage of the Limbic Chair VR.

“We are going to create a system, a world of apps,” explained Künzler. “We've also had third parties asking if they can create software that works with the chair, or make the chair work with their software. What we envision is that, like for a smartphone, you can have many, many, many apps to use with the chair, because everybody who sits on it has a different need, a different desire.”

The Weightless Chair Gets Off the Ground

In 2008, Künzler took the Limbic Chair back to his native Switzerland to further commercialize the product. There, he partnered with a local manufacturing company, Schätti AG Metallwarenfabrik, to bring the Limbic Chair into mass production. The engineers at Schätti modeled the Limbic Chair in Solid Edge and brought the data into NX CAM to manufacture the shells with plastic injection molding. Schätti used Siemens Teamcenter for PLM. The electronics for the Limbic Chair VR were also redesigned with bigger batteries and faster processors.

Künzler tells us the redesigned Limbic Chair will be in mass production in Q2 of this year, and will retail for 2,900 Swiss Franc (about US$3,030). That’s less than half the price of the original Limbic Chair (7,500 Swiss Franc, about US$7,840).

When we spoke to Künzler about the Limbic Chair, his excitement for the product was palpable. He spoke to us while sitting in his wife’s pink and red Limbic Chair, feeling weightless and relaxed. It’s a feeling he wants to spread to others.

“Movement is so essential in the human experience, we just want to give it back to people,” he said. “Now I sound like a mad scientist, I know.”

For a visual demonstration of the Limbic Chair, check out Künzler’s TEDx talk. To learn more about the Limbic Chair, visit the Limbic Life website. For more information on Solid Edge, NX or Teamcenter, check out Siemens’ website.