TOKYO — It takes the engineer about two minutes to adjust the exoskeleton. It's worn like a rucksack, with large straps around the chest to hold it tight. The rest is made up of two disks located on the hips, at the body's rotation axis, and thin rods join cushions on the front part of the thighs. The whole device weighs a little over 6 kilos (13 pounds), distributed between shoulders and thighs.

In front of you, a 30-kilo (66 pounds) water-bottle crate awaits lifting. The first attempt, without the exoskeleton, results in immediate tension in your lower back muscles, and you start to feel fatigue after just two movements. But for the second try, the engineer activates the device. You lift up the crate five, six, seven times in a row without effort. The thrust intervenes on your thighs and upper chest. The movement is quick, almost abrupt, but is still controllable.

The assist suit AWN-03 is the first commercially available product from Japanese company ActiveLink, a Panasonic subsidiary. ActiveLink was among the brands that participated a few weeks ago in Tokyo's International Robot Exhibition, the world's largest robotics show. In the exhibition's "social" and "service" areas, where there were humanoid prototypes designed to intervene in natural disasters, all eyes were on the exoskeletons.

Their development and implementation in Japan fall within a particular context. A low birth rate and a strict immigration policy mean the archipelago's population is aging fast. From 127 million people in 2014, the number of inhabitants is expected to drop below 100 million by 2050. Among the primary collateral effects are a significant work force reduction and growing demand for elderly care, consequences that call for new measures.

Prime Minister Shinzo Abe and his government intend for innovation to boost the performance of the working-age population. Intensive automation is one of the key measures, especially in the services sector and for small- and medium-sized businesses. Larger groups in the car-making and electronics industries are already highly robotized.

The government's "New Robot Strategy" report, published in early 2015, calls for turning Japan into a vast "robot hub" by focusing on the conjunction of the "Internet of Things" and a daily robot presence. According to the Mitsubishi Research Institute, service-oriented robotics in Japan will grow from a $500 million industry in 2014 to a multi-billion dollar one by 2035.

Exoskeletons in Japan find their utility at the junction of three challenges: health care, physical assistance and maintaining the country's level of production despite a shrinking work force. ActiveLink's website features images of a man whose hair has started to turn grey lifting up a small container without effort, and photos of a young woman easily transporting what seems to be a heavy parcel.

Yasunori Nishi, an engineer at Fukunishi, the company that sells ActiveLink products, says the exoskeleton detects the user's movements and assists thanks to a lithium-ion-battery-powered electric engine. It costs about $10,000.

The Japanese aren't the only ones working on exoskeletons. In Europe and in the United States, a number of projects will soon be unveiled in the sectors of defense, industry and rehabilitation. Robo-Mate, an exoskeleton with passive arm modules, has received support from the European Union and is said to have attracted interest from Fiat. The American company Lockheed Martin has developed Fortis, a non-motorized exoskeleton that transfers loads endured by the hands on to the hips and feet. Swiss startup Noonee is meanwhile putting the finishing touches on its Chairless Chair, a portable system that allows users to stand in a sitting position without effort, a concept drawing the interest of several car manufacturers. In the military field also, armors such as KOS or TALOS (dubbed "Iron Man Suit") promise to transform soldier performance.

In Japan, the commercialization of exoskeletons is already underway. Innophys, a startup founded in 2013 at the Tokyo University of Science, has already dispatched about 1,000 units across the country, in particular to Asahi-Sun, an elderly care supplier. Lighter than ActiveLink's AWN-03, Innophys' Exo-Muscle is a little less quick but offers more flexibility for a similar lifting capacity of 22 to 30 kilos (48 to 66 pounds). But Exo-Muscle uses an entirely different technology: compressed air, which is injected into rubber valves that inflate and contract.

"The key part with exoskeletons is the controlling: The device has to understand when to initiate the movement," explains Takashi Fujimoto, Innophys CEO. "As far as we're concerned, we're banking on a switch that reacts to respiration intensity." A sensor placed inside the mouth detects the wearer's exhalation. It's thus possible to control Exo-Muscle without using your hands and without risk that the exoskeleton might activate by mistake. Prices start at about $6,000.

An Innophys exoskeleton — Source: Official Facebook page

Cyberdyne, a global leader in medical exoskeletons, has solved this controlling issue in a more ambitious way. Working together with the robotic department at the University of Tsukuba, Cyberdyne has developed a system of dermal patches with sensors that can detect electrical signals from our nervous system. That way, Cyberdyne's robotic suits react directly to the user's movement intentions.

The HAL exoskeleton series the company has developed includes one model on show at the exhibition, the impressively smooth HAL-CB01. Lighter than all its competitors and also less cumbersome, it sheathes the thighs and hips, and the sensors are located on the lumbars. The assistance it provides is less powerful but more precise and more progressive. More importantly, you can work with the HAL-CB01 for an entire day, for example in a hospital. But the costs are substantial. Only 300 units are available for now, at a rental price that can vary from $800 to $2,000 per month.

Cyberdyne is already working on other prototypes that can assist all four limbs, the torso and even the head. Its Disaster-Recovery model, an entire titanium and carbon-fiber body armor with an anti-radiation jacket, is still in research and development. Last year, the company and Tokyo's Haneda airport announced a partnership for the progressive introduction of portable and mobile robotic material. Eventually, the two wish to team up to develop a new generation of robots designed specifically for civil aviation needs.