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Exoskeletons: A tale of super-humans

When we think of robots, we might imagine a metallic humanoid machine. In my earlier blogposts in the field of robotics I also mostly wrote about anthropomorphic robots. We asked ourselves where human-robot resemblance gets creepy and if robots can have a race.

Today I want to give you an overview of a completely different type of robots: exoskeletons.

History

Robotic exoskeletons are nothing new: the first proposal to develop a “body frame” connected to human limbs and controlled by the human brain dates back to 1883. The first patented exoskeleton design dates back to 1890 and is presented below.

Yagn, N. U.S. Patent No. 420,179 A. Washington, D.C.: U.S. Patent and Trademark Office (1890).

Early exoskeletons had a rough start: they were rigid and clunky, not easy to take on and off and – last but not least – super expensive. And until now, only few exoskeletons have moved from research labs and universities to real-life applications available on the market.

But recent developments in artificial intelligence and advances in robot technologies speed up the process and raise hopes for super-human strength for soldiers, rehabilitation after strokes and factory workers that never get tired.

Definition

Robotic exoskeletons are wearable electromechanical devices that have been developed as augmentative devices to enhance the physical performance of the wearer or as orthotic devices for gait rehabilitation or locomotion assistance.

– Definition by Science Direct

As the field of exoskeletons is continuously evolving, the range of different types is expanding which makes it difficult to define exoskeletons. At least it’s safe to say that exoskeletons are robotic devices that work together with the user and not instead of the user.

Moreover, exoskeletons are not mechanical prosthetics that replace body parts. In contrast, exoskeletons are placed on top of the user’s body and aim to amplify or reinforce human performance. Exoskeletons can cover the whole body or only specific body parts such as upper or lower extremities. The main application area for exoskeletons are the military, industrial contexts and the medical field.

Industrial applications

Exoskeletons can augment the capabilities (such as strengths, agility) of healthy individuals which is beneficial for soldiers or factory workers. Tasks that can be augmented by exoskeletons include heavy lifting, walking in production facilities and extended standing. Companies such as Ford are already using Exoskeletons in their factories. With more than ¼ of Europeans reporting to experience back injuries due to work, exoskeletons in an industrial and commercial context have social and economic implications, too.

Quartz employee tries the Ford factory exoskeleton

New Advancements

Nowadays, many exoskeletons carry tons of sensors and actuators to make the interaction more fluid and natural and protect the user from harm. Other advances cover the material use: Exoskeletons no longer need to be made out of rigid and heavy metal or carbon fiber.

Researcher Conor Walsh, Professor of Engineering and Applied Sciences at Harvard University, and his team are working on exoskeletons that are entirely made out of soft and elastic fabric.

We are developing next generation soft wearable robots that use innovative textiles to provide a more conformal, unobtrusive and compliant means to interface to the human body.

– retrieved from Harvard Biodesign Lab
Bill Gates visiting Harvard Biodesign Lab

One of the biggest limitations of state-of-the-art exoskeletons is the limited information flow between human and machine. Nowadays, exoskeletons only enhance movements of the body or try to predict intentions of the wearer. To create a more natural and seamless interaction, exoskeletons need to be controllable by the wearers’ thoughts!

Prof. Dr. Surjo Soekadar is currently trying to build this bridge between human brain and wearable robotics. At Charité Universitätsmedizin in Berlin he’s the first German professor of Clinical Neurotechnology.

Soekadar is heavily focusing on brain-computer interfaces. His research demonstrated that brain-controlled hand exoskeletons can enable quadriplegic patients to eat and drink independently again.

Open Questions

With technological advancements also come ethical and social considerations: Especially due to the close integration of exoskeletons with the human body, several ethical questions arise: With current high costs of exoskeletons for rehabilitation, will there be unequal accessibility for different social classes? Are we treating humans like machines if we use exoskeletons in the military or industrial field? Are we developing human enhancement? These social concerns should be addressed with the same due diligence than working on technological advancements and monetization of exoskeletons.

Source: Agarwal, Priyanshu & Deshpande, Ashish. (2019). Exoskeletons: State-of-the-Art, Design Challenges, and Future Directions. 10.1093/oso/9780190455132.003.0011.