Japan's cleverest robot is named Takeru Sakurai, and he was born human. When the 24-year-old engineering student dons his custom-tailored robot suit, he suddenly acquires supernatural powers. From a seated position, Sakurai can just about effortlessly lift a 20 kilogram water canister, almost as if it were a loaf of bread. And it's almost all brain power.

Eight sensors positioned on Sakurai's skin pick up the impulses his brain transmits to his muscles and sends them to the robot suit. Then, using motors attached to the hip joints and knees, the robot suit performs the walking and sitting movements intended by its human wearer. With each new movement, the control computer, which Sakurai carries in a backpack, learns how to perform even more physical tasks for its human proxy.

Sometimes, while modeling the robot suit, Sukarai forgets what he is: Is he still a human being, or has he already been transformed into a futuristic machine being? But one thing is clear: In Japan, the divide between human beings and robots is beginning to narrow. Which is, for Sakurai at least, part of the goal. In the future, Sakurai hopes, the suit will help the elderly and the handicapped move more easily.

Sakurai and some of his fellow students at Tsukuba University near Tokyo are currently preparing their invention for an even more impressive feat of strength. The robot suit will be one of the star exhibits at Expo 2005, which begins March 25 in Japan's western Aichi Prefecture. Japan, as the host country of the World Expo, plans to display a veritable army of more than a hundred robots and to remind the rest of the world of its role as an innovative developer of high-tech gadgets and equipment. The robots will greet visitors, perform music, console lost children, sweep, collect garbage and even act as security guards.

Robots in every household

But the world's second-largest industrialized nation isn't just planning to use its tremendous array of robots -- including an astonishingly large number of two-legged, human-like ones -- to upgrade this year's Expo (an event whose purpose has been called into question at least since the Hannover Expo in 2000). More importantly, the hosts intend to bind their domestic industry to an ambitious technological vision: Within as little as ten years, the machines are to become almost ubiquitous in private households, hospitals and companies.

The Expo site near Nagoya, the capital city of Aichi Prefecture, still resembles a drafty concrete structure. But Japan's corporations are already busy trying out the latest tricks with their robots. Even though the country still makes most of its money manufacturing and selling cars, DVD players and sewing machines, hardly any Japanese firm can afford to do without the future-oriented image robots provide.

Toyota is planning the biggest spectacle of all. The world's second-largest automobile manufacturer (the company's motto is "Nothing is Impossible") plans to entertain the Expo's visitors on a daily basis with an entire orchestra of machine beings. Toyota's robots -- some will walk on two legs while others with have wheels -- will play trumpets and wind instruments. Some are even capable of moving their lips, breathing air through artificial lungs, moving their fingers, playing drums and dancing.

The carmaker, which currently has about a hundred of its engineers busy training the robot brigade for the world Expo, is hoping to achieve more than just a PR coup. At company headquarters in Toyota City, head developer Soya Takagi, 56, is seriously thinking about how his so-called partner robots will be able to use their abilities as household helpers or as intelligent vehicles.

The mustachioed engineer is just the right man for this mission. Takagi spent years developing laser robots that are now used in automobile manufacturing. Ever since the 1973 oil crisis, Japan, a country with few natural resources, has placed its bets on industrial robots in an effort to save costs. By now, Japan's factories are filled with about 350,000 robotic devices that perform tasks such as welding, punching and screwing. In fact, Japan has about half the world's industrial robots. Initially, however, the machines were generally used for less sophisticated tasks, while human workers were considered indispensable for manual precision tasks. What's more, the occasional unfortunate incident led many to view the machines as sinister and dangerous. Japan's first victim of robotic activity, a worker at a Kawasaki gear factory named Kenji Urata, was killed 24 years ago when he attempted to revive a defective robot arm. Suddenly the machine began operating on its own, crushing Urata.

My co-worker the robot

But Toyota, encouraged by the heightened intelligence of the current robot generation, even plans to have robots working alongside human assembly line workers during final assembly in the future. Thanks to built-in cameras and sensors, modern robots are becoming increasingly adept at reacting to their human environment. For example, if a human were to touch a robotic arm, today's generation of robot would be more likely to carefully withdraw its arm, instead of stubbornly lashing out.

But there is a deeper motivation behind the Japanese craze for robots. Japan's population is aging more rapidly than that of any other country. By 2050, one-third of all Japanese citizens will be older than 65. Instead of importing foreign workers, Japan, hoping to preserve its relatively homogeneous culture, prefers to meet its needs for workers or care-giving personnel with homegrown machine beings.

The affection that the Japanese lavish on their electronic creations may seem a little odd to western sensibilities. But it's not that unusual in a country whose traditions are based on ancient, nature-oriented religions that also deify inanimate objects such as stones.

Entire generations of Japanese grew up with cartoon series in which robots are portrayed as heroes. In fact, Toyota developer Takagi and his team have even drawn some of their inspiration from a cartoon hero named Gundam, a warrior robot. Just like Gundam, Toyota's two-legged robot "i-foot" is able to carry people in a sort of litter.

Today, it is Toyota that is putting its Japanese competitors on the spot with its robot brigade. But it was Honda, in the mid-1990s, that became the first automaker to unveil a human-like robot. Soon all of Japan had adopted the machine as a mascot of sorts. Then Prime Minister Yunichiro Koizumi even took the robot, named "Asimo," along on a state visit to the Czech Republic.

Now Asimo is getting a facelift and an upgrade from Honda engineer Satoshi Shigemi. By improving the robot's balance, Shigemi has managed to up its top speed from 1.6 to 2.5 kilometers an hour. Asimo also uses visual sensors to analyze human movements, enabling the robot to hand over objects or to accept articles that are handed to it.

Mixing biology with technology

Japan's robots will need these kinds of skills if they are to be used as helpers in daily life. The Japanese government sees its use of robots at the Expo as an important test case to determine how successfully robots can coexist with human beings, says Kayuza Abe of Japan's State Organization for New Industrial Technology (NEDO), which has provided 3.2 billion Yen (€23.56 million) to fund the robot demonstrations. The extra funding is necessary; robots have never been operated in such close quarters with thousands of visitors as will be the case at the Expo, says Abe in a conversation in his office in a Tokyo skyscraper. While speaking, Abe flips through a thick blue binder containing the robot models, some still top-secret, that Aichi will be showing off to the world.

The Japanese engineers want to be absolutely certain that the Expo robots will not be able to injure anyone, even if they fall over by mistake. It's also important to ensure that they won't begin moving independently or be short-circuited if it rains. As an extra precaution, each worker robot will always be accompanied by a human minder at the Expo.

When visitors arrive, "Wakamaru," a rolling robot made by Mitsubishi Heavy Industries, will greet them in four different languages. The mechanical host has a vocabulary of about ten thousand words. Meanwhile "PaPeRo," contributed by electronics manufacturer NEC, will have the job of entertaining children while their parents explore the Expo.

A group of robots will likewise be rolling around the exhibition space to provide security for visitors. They'll use their camera eyes and sensors to locate fires and suspicious objects, promptly reporting anything they discover to a centralized computer command center. At night, cleaning robots manufactured by electronics giant Matsushita will sweep the site and vacuum up paper, empty beverage cans and other refuse.

Helping the elderly and disabled

But the real stars of the show will be the prototypes of newest generation robots the Japanese plan to unveil. A special building will display robots designed as helpers for the elderly or the disabled, including Takeru Sakurai's robot suit and an intelligent care-giving robot.

Earthquake-prone Japan is also placing high hopes on robots with animal-like features. For example, "Studious," a six-legged robotic bug with learning capabilities, is designed to crawl through collapsed buildings, locate survivors and then transmit its observations wirelessly to a computer. "Tekken" ("iron dog"), unlike Sony's well-known mechanical puppy "Aibo," won't just be able to play around like a real dog, but will also act as a guard dog, even chasing after would-be burglars.

But the darlings of many Japanese developers are the so-called humanoids -- robots in human form designed to serve as household helpers. The developers insist that the only way to dispel people's fears of machine beings is with robots that actually look like humans. But these artificial beings still have many hurdles to overcome before they are able to successfully coexist with human beings in the household -- hurdles that in many cases are as seemingly innocuous as a fold in a carpet.

Even "Qrio," the two-foot humanoid robot made by electronics manufacturer Sony, is not immune to involuntary plunges. In Sony's robot laboratory in Tokyo's Shinbashi district, developer Takashi Katoku and his team are tweaking the robot's computer software to make him more sure-footed. As soon as Qrio's sensors detect that he's about to fall over, Qrio lifts an arm to protect his face and turns his head to the side.

Of course, Qrio certainly has an easier time of it than many robots of the same species. As a creation of the entertainment industry, Qrio is even encouraged to play around. With the click of a mouse, Katoku can instruct the Sony robot to dance. A green light suddenly begins flashing in Qrio's eye sockets, which is supposed to be a sign of inner composure and deepest concentration, and then the robot starts performing a rhythmic Japanese folk dance.