"It turns workers away from being a weightlifter and into a craftsman," Maxwell said.
While Ekso Bionics' Harding sees exoskeletons on an evolutionary path toward ever-greater sophistication — much as large portable phones of the early 1990s morphed into today's smartphones — it may not be that easy to cut costs, simplify the technology and ensure widespread adoption.
"Even though there are processors and sensors, there's still a lot of physical matter that has to be machined and built," said Discern's Saffo, who is also a consulting associate professor at Stanford University's engineering school.
The other limitation is battery life. Batteries can be made only so powerful before turning into a bomb, Saffo said. Boeing knows the risks in working with larger versions of the lithium-ion cells found in mobile phones and other electronic gadgets: It's still trying to figure out the cause of electrical faults that grounded its 787 Dreamliner.
"Until you have higher-density power storage, you're always going to be looking for a plug for your exoskeleton," Saffo said.
The exoskeleton industry is attractive because the potential is vast and the large competitors are few, according to Lockheed and Cleveland-based Parker Hannifin.
Lockheed envisions a leap forward in battlefield mobility with its Human Universal Load Carrier — whose HULC acronym evokes images of Marvel Comics' Incredible Hulk, a green, super- strong mutant and sometime-ally of Iron Man. HULC is intended to let a soldier lug a 200-pound pack with minimal effort over a 20-kilometer (12.4-mile) hike, Maxwell said.
Back strain is the most common non-combat injury because of the heavy packs soldiers carry, Maxwell said. Lockheed licensed some technology from Ekso Bionics to produce the HULC, which is set to enter a second development phase this year as the system is refined so it can be worn under a uniform.