Bionic revolution: 8 exoskeletons leading the field

Sharing a lineage with the first untethered powered exoskeleton, which was developed in a U.C. Berkeley lab, the Ekso GT is a wearable bionic suit that enables individuals with any amount of lower extremity weakness to stand up and walk over ground with a natural, full weight bearing, reciprocal gait. It is currently used in clinical settings to help with gait training, and a progressive step mode helps facilitate patients' escalating skills. In autonomous use, patients utilize crutches to fire each step.

Designed at Vanderbilt University, the technology behind the Indego was acquired and developed by Parker-Hannifin. The 26-pound exo enables clinicians to conduct over ground, task specific gait training and offers people with mobility impairments a new level of independence. It was designed for personal use, but like the Ekso it is currently being researched in clinics as a tool for therapy. Actuation is initiated by leaning forward or backward.

When a person moves, the brain sends various signals to muscles via nerves. Those bioelectrical signals are readable on the skin's surface.

HAL's Living Support Model reads a wearer’s BES and reinforces muscles in the lower limbs accordingly. The suit enables wearers to walk, stand up, and sit down just by thinking.

A budget model, the Power Loader Ninja from Japanese manufacturer Activelink  is expected to sell commercially for about $5000 when it debuts sometime this year. The suit is meant to be a workhorse, not a rehabilitative tool, and at the price point the company expects it to appeal to farm workers and delivery personnel.

Boasting first-in-class FDA clearance, the ReWalk system provides user-initiated mobility through the integration of a wearable brace support, a computer-based control system, and motion sensors. The system allows independent, controlled walking while mimicking the natural gait patterns of the legs, similar to that of an able-bodied person.

Exoskeletons made their debut in the battlefield. HULC is an un-tethered, hydraulic-powered anthropomorphic exoskeleton developed in the same U.C. Berkeley lab that gave rise to Ekso Bionics. Hydraulic actuation is more robust than electro-mechanical actuation found in other models, which makes it well suited to the rigors of war.

Not to be left behind, Chinese officials debuted an exoskeleton last year. The device appears to be hydraulically actuated. A CCTV report said that the exoskeleton has a coefficiency of 5:1 -- for every ten pounds it carries, the wearer feels one pound. The CCTV report also said that the PLA would be refining the device for frontline use in years to come.