The dawn of the age of the exoskeleton

In recent years, members of Seattle Mountain Rescue have been exploring an intriguing piece of technology on their rescue missions. These individuals don exoskeletons, powered assistive devices attached to their hips and legs, designed to enhance lower-body strength during climbing or carrying heavy loads. These devices, known as human exoskeletons, aim to boost the speed and endurance of rescuers when every second counts—during critical searches for stranded individuals.

Human exoskeletons are external mechanical structures that attach to specific body parts, augmenting the wearer's physical capabilities. They are increasingly being adopted in physically demanding fields, including warehouse work, assembly lines, rescue operations, and firefighting. Companies like IKEA, Ford, Boeing, Mazda Toyota, and even the Ukrainian military have started integrating these devices into their operations.

The potential benefits of exoskeleton technology have been demonstrated in various settings. A Finnish project called ExoPELA found that exoskeletons reduced muscle load and strain in rescue and firefighting tasks, leading to noticeable improvements for users. Meanwhile, Ukrainian soldiers wearing Hypershell exoskeletons reported becoming less fatigued, working faster, and maintaining combat effectiveness for longer periods on the front lines.

These findings highlight the growing interest and promise of exoskeleton technology in enhancing human performance across a range of demanding tasks.

The development of exoskeleton technology has been driven by advancements in robotic motors, sensors, and control systems, making these devices more affordable and accessible. The concept of augmenting human performance with exoskeleton-like devices dates back earlier, with the first patent filed in 1890 by Russian inventor Nicholas Yagn for a wearable exercise apparatus.

Over the past century, numerous actuated robotic exoskeletons with electronic control systems have been developed, leading to a surge in research and commercial applications.

Modern exoskeletons typically consist of lightweight mechanical frames with ergonomic attachments to the human body, such as the waist, trunk, and upper or lower limbs. Actuators within the device convert electric power from batteries into mechanical movement, generating forces that support or enhance the wearer's movements. Control units embedded within the exoskeleton define the trajectories of these movements and determine the amount of force applied to the user.

The device adapts its assistance based on the task and the user's state, using sensors to determine the necessary force and trajectory.

Exoskeleton assistance can be categorized into three main types: power augmentation, assist-as-needed, and full robotic control. Power augmentation increases the force capabilities of the user, commonly seen in assistive exoskeletons like those used by IKEA and in Ukraine. Assist-as-needed or resist-as-needed settings provide support only when necessary, often used in rehabilitation devices to help users recover lost capabilities.

Full robotic control, on the other hand, allows the exoskeleton to assume complete control over a part of the body, typically for users with lost motor functions, such as someone with a spinal cord injury. These different modes of operation can be combined and tailored to specific tasks, environments, and user needs.

Currently, most exoskeletons rely on sensor feedback to define their behavior, relying on mechanical components for operation. However, future advancements could potentially enable exoskeletons to be operated with signals from the wearer's muscles or brain, although this remains a significant challenge due to the need for invasive interfaces and extensive user-specific calibration.

Despite these challenges, the power and potential of exoskeleton technology continue to grow, with estimates suggesting that the sector could double or even triple in size by the mid-2030s.