Chairless Chair Exoskeleton System
A Pain in the Back
When people need to spend a long day at work standing on their feet, complaints of back pain and leg fatigue are extremely commonplace. In many cases sitting down at work is not possible, due to chairs getting in the way. The only option is to spend all day on your feet, which can be quite uncomfortable and wearing. This frequent and repetitive standing work can have a detrimental effect on concentration and performance, as well as physical fatigue. It can also result in worker complaints and more time taken off work, especially amongst older employees. Swiss start-up company, Noonee, has now developed a solution for relieving the strain on legs and backs that is both imaginative and simple – the chairless chair. Unlike other exoskeleton concepts, the batteries of the chairless chair are not limited to only lasting a few hours, but rather they can last several days. Compact, flat DC motors also play a part in the system's design.
Substantial Support With Stamina
An exoskeleton ("exo" = external) is a supporting apparatus which is on the outside of the body, in contrast to an internal skeletal structure. We know of the natural version from crabs, insects, and other arthropods and artificial exoskeletons have been featured in science fiction and action films. In movies, these exoskeletons are imagined to be fighting machines that turn ordinary beings into invincible super heros. However, artificial exoskeletons have long since existed in reality, in different forms and for different purposes. They can provide assistance in cases where natural muscle power is inadequate, e.g. for lifting heavy components or working overhead with a bulky grinding machine for long periods. People with paraplegia can walk again with an exoskeleton, as was demonstrated in Brazil at the kick-off to the opening game of the football World Cup in 2014.
These real exoskeletons have two serious disadvantages: they are fairly heavy, usually significantly more than 20 kilograms, and their batteries last for little more than two hours. For these reasons alone, they are therefore far from capable of being used in everyday life.
Keith Gunura, CEO of Noonee, had researched exoskeletons before he established the start-up enterprise together with Olga Motovilova in Rüti, near Zürich. "We wanted to construct a supporting system that was extremely light and simple, did not run out of power during continuous operation, and also provided a solution to a wide range of everyday problems" Gunura explains.
In order to sit, the shock absorber element is locked by the FAULHABER micro DC motor, and the lock is released when walking. The seat inclination is infinitely variable.
A Promise of Relief, For Workers and Management Alike
Gunura had his own experience of complaints caused by standing for long periods during a student job at a packing service provider in England. "Particularly older co-workers had problems, and I heard the concern of fatigued colleagues every evening", he recalls. The two founders of Noonee discovered that management teams of major companies were also concerned about this problem by jumping into the deep end. During a workshop for start-up entrepreneurs at the Swiss Technical University in Zurich (ETH), one of the exercises involved calling potential customers and asking about their interest in a product. "The workshop leader dialed a number and handed us the receiver, saying that someone from one of the biggest car manufacturers in the world would answer the phone" explains Keith Gunura.
To the surprise of both founders they were not met with skepticism, but rather with open doors, even though they didn't even have a prototype yet. And when the first prototype failed during the demonstration, the automotive industry managers just wanted to know when the next attempt was taking place. "German companies in particular view demographic development and the increasing shortage of experts as a major strategic challenge" explains Keith Gunura about the major interest shown by potential customers. "They desperately wanted to do something to relieve the strain on their experts during production, and make it possible for employees to remain active for longer."
Proof In Execution
A practical test was carried out at the Audi plant in Neckarsulm, which provided some important tips for optimizing the first prototype generation. A second series of tests were carried out a few weeks later in three-shift operation at the Ingolstadt plant. "The managers thought that the employees would be skeptical. Instead, they contacted the management and volunteered to take part in the experiment. It only took a few minutes to learn how to use the equipment."
Noonee has actually succeeded in keeping the concept and the technology extremely simple. A supporting strut, which also serves as the seat, is fastened to the back of the legs. The prototypes were made from titanium, but could be also made from carbon fiber in the future, which would make them even lighter. A joint at knee height provides flexibility, and the shock absorber element behind the lower leg can be locked in stages if the user wishes to sit down. The entire Chairless Chair is attached using straps at the hip, knees and ankles. When sitting, the weight is led directly into the ground, therefore relieving the legs and the lower back. The entire construct only weighs a few kilograms, is easy to put on and is hardly noticeable when walking.
The human legs are still responsible for movement – which is an advantage compared to active exoskeletons, which can result in muscle wastage due to "over relief". The users can sit down anytime, anywhere, while attaching parts to a vehicle chassis, for example. They have freedom of movement and their seating facility is always available.
Support for A Diverse Userbase
To turn the flexible construct into a stable seat, all you have to do is operate a switch that is attached to the strap. Two FAULHABER small DC motors activate the stop valve in the hydraulic elements of the shock absorbers, and the support locks in the required position. The lock releases again when the user stands up.
"We required an extremely flat motor with high torque and steps that were as small as possible for this application", explains Keith Gunura. "Of course, it had to be as light as possible and have minimal power consumption." The cogging-free small DC flat motor with a gearhead was just the job for these requirements. As well as its small dimensions (26 mm in diameter x 19 mm in length), its strengths include extremely low current consumption with a low starting voltage, and high dynamics thanks to the minimal inertia of the rotor. The small 6 Volt battery still did not require recharging during the practical test, even after a week of continuous operation. The motorized lock also passed the stress test (two full shifts in succession) with flying colors.
The product is not yet ready to go into production, but development is continuing at full throttle with active support from potential customers and (as far as the motor and its functionality are concerned) FAULHABER. Meanwhile, the fledgling company's inbox has already received a flood of inquiries. "We receive multiple emails every day from people who are interested in our seat support" says Olga Motovilova, who is now responsible for operational business as COO. "They come from people such as surgeons, priests, film crews, hunters and anglers from all over the world." The plan is for the first chairless chairs to be delivered mid-2016.
To learn more about the chairless chair, and to keep up with this startup company, visit the Noonee website.