What are exoskeletons, and how do they work?

Exoskeletons are wearable devices designed to augment, support, or restore physical movement by providing external structural and mechanical assistance. They consist of a framework worn on the body, often incorporating sensors, actuators, and control systems to interact with the user’s movements. These devices can be passive (relying on mechanical components like springs or counterweights) or active (using motors, hydraulics, or pneumatics). For example, medical exoskeletons help individuals with mobility impairments walk, while industrial exoskeletons reduce strain on workers lifting heavy objects. The core idea is to transfer load or enhance strength by working in tandem with the user’s musculoskeletal system.

Exoskeletons operate by detecting the user’s intended movement through sensors, such as electromyography (EMG) sensors that monitor muscle activity or inertial measurement units (IMUs) tracking limb position. The control system processes this data to trigger actuators—like electric motors—that generate force or torque at joints (e.g., knees, hips). For instance, when a user wearing a lower-body exoskeleton begins to stand, sensors detect muscle activation and joint angles, prompting actuators to assist in extending the legs. Some systems use preprogrammed gait patterns for rehabilitation, while others adapt in real time via feedback loops. Power is typically supplied by batteries, with efficiency being a critical design consideration to balance performance and weight.

Developers working on exoskeletons face challenges like ensuring low-latency response, minimizing device weight, and optimizing energy consumption. Software plays a key role: control algorithms must interpret sensor data accurately to avoid misalignment with the user’s natural movement. For example, a factory exoskeleton might use torque sensors in its arms to detect when a worker lifts a box, then apply proportional force to reduce back strain. Biomechanical compatibility is also crucial—exoskeletons must align with human joint kinematics to avoid discomfort. Open-source platforms, such as ROS (Robot Operating System), are sometimes used to prototype control systems, allowing developers to test and refine actuation strategies before hardware integration.