How Close Are We to Having Powered Exoskeletons?

Technological advances have often focused on making life easier for people, either by saving them time or adding an element of convenience to completing tasks by reducing the amount of effort needed. However, there are also technological developments that aim to enhance human performance rather than simply making tasks easier. One example of this is powered exoskeletons. Here is an overview of the purpose and potential applications for these devices, and a look at how close we are to getting powered exoskeletons.

What is a Powered Exoskeleton?

Powered exoskeletons are wearable mobile machines that are powered by various technologies, such as pneumatics, electric motors, hydraulics, levers, or a combination of these technologies. The purpose of these devices is to improve the strength and endurance of limb movement. While the idea of such a device may seem modern and innovative, it is actually a concept with a long history as the first powered exoskeleton was developed in Russia in 1890. This passive device required human input and used energy stored in compressed gas bags. A collaboration between the United States Army and General Electric led to the first true mobile machine in the 1960s. The powered armor suit they created was called Hardiman, and it was powered by a combination of electricity and hydraulics.

The Applications of Powered Exoskeletons

There are four main applications for powered exoskeletons; medical, military, civilian, and industrial.

• Medical0 There is the potential for powered exoskeletons to play an important role in elderly care. Another medical use is in the rehabilitation of patients who have suffered a spinal injury or stroke. Furthermore, it is possible that surgeons could wear powered exoskeletons to perform surgery with enhanced precision.
• Military - Military applications have been an important focus of developments. A powered exoskeleton could allow soldiers to carry heavier loads while running. It may also increase their productivity and decrease fatigue.
• Civilian- There are lots of possible applications for civilians, but one that has gained attention is for firefighters and other rescue workers to wear them to increase chances of survival in dangerous situations.
• Industrial- Industrial workers could wear powered exoskeletons to help them with repetitive tasks and lifting greater loads. It is also a useful technology in industrial environments because of the aging workforce. Older workers are at greater risk of work-related musculoskeletal diseases, and this technology could reduce this risk.

What is Available Now?

Although powered exoskeletons are not at the point where they are being used or are available to buy, there have already been some examples of working powered exoskeletons. According to How Stuff Works, defense contractor Raytheon demonstrated the experimental XOS-2 in 2010. This is a wearable robotic device that is guided by the human brain. Without any effort on the part of the wearer, the user can lift up to three times the amount of the weight of an unassisted human.

Is There Anything Under Development?

One of the main players in the development of powered exoskeletons is the United States Army, says Futurism. They want to enhance the capacity of soldiers on the battlefield, but their developments could also have other applications. The technologies developed by their contractors range from full-body suits to smaller devices, such as mechanized ankle supports. The US Army has now employed two companies to focus on developing powered exoskeletons. Lockheed Martin has been given $680,000 to further develop the Onyx system. This is an exoskeletal system for the lower body that attaches to the feet and legs. The other company the Army is using is Dephy. Although the US Army would prefer a full-body suit, Dephy is developing the Exo-boot, and this product is a lot further ahead than many other products in the powered exoskeletal race.

The Limitations of Powered Exoskeletons

So, if powered exoskeletons already exist, why are they not in use or available on the market? This is because powered exoskeletons still have any limitations, and it is important that these are resolved before these technologies can be put to use. Some of the limitations include the following:

• Power supply- At the moment, powered exoskeletons care only powered for a couple of hours at the most. One of the main problems that designers face is in developing these systems is creating a power source that is capable of powering an exoskeleton for much longer.
• Skeleton- Finding the right material to create the skeleton has posed some challenges. Current creations have used either steel or aluminum. However, steel is not ideal because of its weight, and the outfit has to work harder to move because of this. Aluminum is also not the best choice because although it is lightweight, the exoskeletons soon break due to fatigue.
• Actuators- The actuators are the parts that make the joints move, and weight has been one of the issues with these. Hydraulic cylinders have been a popular choice as they are powerful and precise. However, the weight of these is an issue. A further problem is that pressurized hydraulic fluid is potentially dangerous to humans if it leaks. An alternative to hydraulic cylinders is electronic servomotors as these are efficient and power dense.
• The flexibility of joints- It is tricky to create joints in exoskeletons that can exactly replicate the motion of ball and socket joints, such as the shoulder and the hip. A further challenge is the spinal flexibility. The spine is like a stack of limited motion ball joints, and it is difficult to match the movement externally.
• Power control and modulation- A single-speed device with no controls is not an option as this is too limiting.
• Size variations- It is impossible to create a one-size-fits-all powered exoskeleton as there are too many variations in the size of humans and the lengths between their joints.

How Close Are We to Having Powered Exoskeletons?

Many companies and organizations are continuing to work on powered exoskeletons. Although there have been many successes in making devices that function well, there are still many challenges that the developers must address. It is likely that partial exoskeletons, such as boots or lower body powered exoskeletons, will reach the market long before a fully functioning full-body powered exoskeleton. No time scale has been given for when these will hit the market, but developers believe they are getting closer.