"Oh, my legs! Aargh, my back!" Complaints like this are not uncommon when people have to spend a long day standing up. In many cases it is not possible to sit down at work because there must not be any chairs in the way. You are therefore on your feet all day, which can be quite uncomfortable. This can have a detrimental effect on concentration and performance. It can also result in physical 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 exo-skeleton concepts, the "Chairless Chair" batteries don't just last for several hours, but several days. Motors from FAULHABER also play their part.
Substantial support with stamina
An exo-skeleton (exo = outer) is a supporting apparatus which is on the outside of the body, in contrast to our bones. We know of the natural version from insects and the artificial exo-skeletons in science fiction films. In these films, exo-skeletons are imagined to be fighting machines that turn ordinary beings into invincible warriors. However, artificial exo-skeletons have long since existed in reality, in different forms and for different purposes. They provide assistance in cases where muscle power is inadequate, e.g. for lifting lift heavy components or working overhead with a bulky grinding machine for long periods. People with paraplegia can walk again with an exo-skeleton, as was shown in 2014 in Brazil at the kick-off to the opening game of the football World Cup.
These real exo-skeletons 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 generally used in everyday life. Keith Gunura, CEO of Noonee, had researched into exo-skeletons before he set 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 provided a solution to a wide range of everyday problems", he explains.
Holding on to experts by means of relief
He 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 cry 'oh my legs' every evening“, he remembers. The two founders discovered that the management 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 dialled 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 scepticism but wide open doors, even though they didn't even have a prototype yet. And in spite of the fact that 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."
Proven in practice
A practical test was carried out at the Audi plant in Neckarsulm, which provided some important tips for optimising 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 sceptical. 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 fibre in 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 exo-skeletons, 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.
Car manufacturers, surgeons and priests
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 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 DC flat motor with gearhead was just the job for these requirements. As well as its small dimensions (26 millimetres in diameter x 19 millimetres 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 motorised lock also passed the stress test (two full shifts in succession) with flying colours. 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 in mid-2016.