Mad about Science: Powered Exoskeleton

By Brenden Bobby
Reader Columnist

The idea of a powered human exoskeleton is an old one. Sigourney Weaver whooping the crap out of the xenomorph queen with a power loader in 1986’s Aliens is forever ingrained into my mind whenever the subject comes up. The idea of artificially empowering our frail human bodies is a very attractive one in the age of rapid gains and exploding technology. Humans have made tremendous advances in the fields of cancer treatment, weight loss and dietary supplements in recent years.

Powered exoskeletons — sometimes called power armor in contemporary sci-fi — have limitations just like everything else. Lifting heavy objects requires enough force applied to move the weight, which means the item lifting the heavy object needs to be sturdy enough not to break while exerting those forces.

The powered exosuit from Aliens. Courtesy photo.

Organic structures are really good at applying varying amounts of force because of the self-replicating nature of our cells. A person attempting to lift something heavy may struggle at first; but, if they keep lifting lighter objects over a period of time, they’ll eventually be able to lift it with relative ease. Whenever you exercise, particularly with weights, your muscles tear. Tears in your muscles signal your body to repair those tears by adding cells to fill the voids, creating more bulk and more muscle, effectively preparing your body to face that challenge again in the future. This needs to be done organically and over time, so as to not cause severe and permanent damage to your body. Our cells are great at fixing little things and improving, but they’re not as good at addressing catastrophic damage.

The real key to success in designing a powered exoskeleton for a healthy body is not to replace the function of your muscles, but to augment and improve upon them, as well as taking some of the stress from them and placing the bulk of fatigue on a non-feeling structure, such as a metal rod.

There is a greater purpose to designing a powered exoskeleton for a body that no longer functions the way it was intended, due to damage or genetics. One example of this is the Lifesuit, developed by former Army Ranger Monty Reed. Reed broke his back while parachuting in 1986, which robbed him of the use of his legs. In an attempt to regain mobility, he spent a number of years developing a powered exoskeleton that would give him the opportunity to walk again — not just for a few feet, but to complete a 5K race. In 2005, Reed competed in Seattle’s St. Patrick’s Day Dash, utilizing the exoskeleton to walk around 2.5 feet per second. As a point of reference, the average human walking speed is around 4.7 feet per second.

Power armor and exoskeletons are frequently showcased in militaristic science fiction. Popular video game franchises like Fallout and Halo have power armor front and center, presenting an alternate future in which knight-like warriors perform superhuman feats augmented by powerful technology. Seems like something the military would be into, right?

It turns out a number of factors have pushed the military away from trying to utilize power armor suits. The biggest and most obvious factor is powering it. How often does your phone fail to charge, only to die mid-selfie during peak lighting? Imagine that, but it’s your entire body now locked in a standing position in an active warzone.

Additionally, equipping infantry with multi-million dollar suits is obscenely expensive. Building a vehicle that can achieve more with the same investment serves multiple purposes including transporting highly mobile personnel is far more attractive to military leaders than super-powered infantry that would make prime targets for enemy drones or rockets. The military has explored this multiple times, particularly through the 1980s, but it’s never made sense to make the leap.

You would think the power loader exoskeleton from Aliens would make sense to develop and use instead of a cumbersome vehicle like a forklift that requires extensive training and certification to operate. This is actually not the case. Forklifts and motorized pallet jacks are extremely agile and fully capable of completing the bulk of logistical necessities required of them. However unusable a forklift or power jack may be in rough or rural terrain, an easier solution is to simply devote the resources needed to pave an area seeing a higher influx of goods being transported in high enough quantities to necessitate the use of a lift or jack.

The best uses for power exoskeletons harken to their original design in 1890, to assist in movement for those that may be lacking in strength or endurance due to debilitating injury or genetic deficit. Initially, these were powered by compressed gas similar to the powered gate piston of your car’s hatchback. Speed and power critically lacked in these early designs, but that may have been a good thing, as proper designs to reduce catastrophic failure such as extreme hyperextension weren’t actively developed until the 1960s.

Imagine for a moment your arm being physically bound to the arm of a forklift. Your movements control the lift for the most part, but if something goes wrong, that machine could easily tear your arm right out of the socket. That was the danger of early exoskeletons.

Much of the research conducted into these types of suits has been recently applied to humanoid robots intended to be utilized by first responders when dealing with situations too dangerous for humans to approach. There have also been applications to help reduce the effort required for firefighters to ascend stairs in major metropolitan areas. Another major field of research is applying this to telemobility, such as the applications for remote assembly or surgery. The ability to train workers in impoverished countries remotely, while still interacting directly through something like a robotic arm mirroring your own movements could be transformative for leapfrogging technology and economic growth in struggling areas.

One day, I’ll own a set of Mjolnir Mark V armor; maybe then I’ll finally be able to dunk a basketball.

Stay curious, 7B.