Not so long ago, children with a rare neurological disease were able to walk for the first time thanks to a new robotic exoskeleton. These devices - which are essentially robotic suits that give artificial movement to the user's limbs - are becoming an increasingly common way to help people who cannot use their legs to walk. But while modern exoskeletons are mostly clumsy, heavy devices, new technologies could make them much easier to use and more natural. You've probably already guessed where this is heading: fake leather.
Exoskeletons have been in development since the 1960s. The first exoskeleton was a bulky set of legs and clawed gloves that only vaguely resembled an Iron Man suit. He had to use the power of hydraulics to help industrial workers lift hundreds of kilograms of weight. That project was unsuccessful and did not work, but the options that followed got better and better. Today, people can finally use exoskeletons to partially enhance their own capabilities, re-learn to walk with their help, or even interact with computers using touch or "tactile" feedback.
Typically, these devices consist of a chain of links and strength joints that work in tandem with a person's own bones and joints. Artificial limbs are securely attached to the limbs of a person and continue his movements. The exoskeleton can be controlled by a computer - for example, if it is performing a physiotherapy routine - or by monitoring the electrical activity in the user's muscles and supporting the force they generate.
Heavy and painful
Despite half a century of research, exoskeletons are still not widely used. This is largely because they were uncomfortable to wear for long periods of time, as people's bodies are different from costumes, which are made as one Procrustean bed. Some exoskeletons fit the human body better, but if the robotic joints and the user's real joints do not rotate synchronously, discomfort or pain may result. All this is compounded by the rigidity of each part of the suit.
Another problem, especially with upper body exoskeletons, is their weight, as they are made of durable materials that can hold heavy weights and support the body. Modern suits also don't cope very well with changes in temperature or rain, making them difficult to use in the real world. And people still cannot get used to their appearance.
To make exoskeletons more practical and pleasing to look at, we need innovation: we need to make them a "second skin" rather than a giant robotic suit. Usually exoskeletons use heavy electric motors, but lightweight actuators can also be used as pneumatic muscles. They can apply similar efforts as electric motors, only they will weigh several times less. These muscles consist of a rubber bladder surrounded by a woven sleeve. Under pressure, they increase in diameter and contract in length, pushing the joint. And although they are made of lightweight materials, they can apply force, which is enough to lift many hundreds of kilograms.
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Soft robotics
Yet even these lightweight actuators must be attached to a rigid mechanical structure on the user's body. Scientists at the University of Salford's Center for Autonomous Systems and Robotics are developing another alternative: soft robotics. This technology uses physically soft, advanced materials to perform the same tasks as traditional rigid robotic devices. They are particularly well suited for interacting with people, as soft often means light and there is less chance of injury when hitting a person.
They recently developed a new "soft continuum drive" that bends like an elephant's trunk. Unlike a traditional rigid robotic joint, encountering resistance in one part of the body, it will bend in all directions along its entire length. By wearing a tight-fitting suit with such drives, we could have a soft exoskeleton that flexes exactly where the wearer's joints are. Consequently, the suit is perfectly suitable for different wearers without the need to mechanically adjust or calibrate it. Plus the system is lightweight and can be worn as clothing instead of a bulky mechanical frame.
Exoskeletons are starting to be marketed commercially and we are likely to see a lot of new things in the years to come. In 2012, the paralyzed woman Claire Lomas even completed the London Marathon wearing an exoskeleton. But there are still many engineering problems that will have to be solved before we see widespread use of such systems. At the very least, we need a way to power these suits without having to plug them in every half hour.
ILYA KHEL