OSAKA -- Research into the creation of humanoid robots is leaping ahead. Robot comedians are already making audiences laugh, and department store customers can get help from robotic shop assistants.
But there are far bigger implications in such advancements. In developing robots, researchers ask, "What does it mean to be human?" The continuing evolution of the robot is providing valuable insight into this most fundamental of questions.
Step by step
The word "robot" was first used around 1920 in a play by Karel Capek. In 1969, Ichiro Kato, at the time a professor at Japan's Waseda University, created the WAP-1, a robot with just legs. In 1973, he developed a bipedal robot with arms, legs, eyes and ears. Eleven years later, he introduced a robot that could walk at almost the same speed as humans.
Japan has continued to be a world leader in the development of bipedal robots. In 1996, Honda Motor introduced the P-2, the predecessor to Asimo. This highly sophisticated robot, which did not require any external cables and had autonomous control, surprised the world. Next in line, Sony unveiled its Qrio, a robot that dances.
But while both Asimo and Qrio can walk on two feet -- one of the foremost characteristics of human beings -- both robots have boxy torsos and limbs and come in such colors as white or silver. In other words, they look like robots.
Hiroshi Ishiguro, a professor at Osaka University, wanted to do something about this. In 1999, he developed Robovie, a robot modeled on the upper body of a human. Since then, he has been developing increasingly humanlike robots.
Ishiguro created a buzz when he unveiled a robotic "woman" with skin made out of resin at Expo 2005 Aichi Japan. The following year, Advanced Telecommunications Research Institute International, or ATR, developed Geminoid HI-1, a robot that looks like Ishiguro. It received worldwide acclaim.
Ishiguro went on to develop robots that function as department store clerks and Beicho Android, a robotic replica of storyteller and national treasure Katsura Beicho. With the help of playwright Oriza Hirata, he even put on a play performed by Geminoid F, a female version of the robot.
Humanoid robots at stores or on stage immediately draw attention and are useful for entertainment. But Ishiguro says his ultimate goal in robotic research goes further: "By creating something that looks human, I'm trying to understand what it means to be human."
In the attempt to recreate human characteristics, we can begin to see what it is that defines us as human beings. For instance, when we breathe, movement is found not only in the chest but also slightly in the shoulders. To make a humanoid look like it is breathing, adding movement only to the chest is not enough, and it ends up looking rather like a wax dummy. Similarly, robots that can only make formulaic responses during a conversation or fail to react instantly to loud noises appear far from human.
Research into humanoids may also help understand how people interpret expressions of anger or joy. "Robots are a mirror to the human soul," Ishiguro said.
The key to giving robots more humanlike movements lies in artificial muscles. A team of researchers at the Tokyo Institute of Technology developed such muscles out of hundreds of thin rubber tubes made from reticulated synthetic fiber. By inflating each of the 400 tubes with air, the fibers start to move in way similar to real muscles. Nagoya University, meanwhile, has developed a material that can stretch up to 10 times its own size. Using supple artificial muscles will make humanoids increasingly indistinguishable from humans.
Facial expressions are another factor that makes humans what they are. The Beicho Android can close and open its eyes and move its eyebrows and cheeks. "Expressions such as surprise or sadness are relatively simple," said Kohei Ogawa, an assistant professor at Osaka University who helped develop the humanoid. "The difficult expression is shyness." Another difficulty? Extreme anger can cause a humanoid's resin skin to rupture.
Ishiguro is busy working on creating humanoid men and women that are attractive -- and then some. By combining the elements of a beautiful face and body, "I want to see if I can create something that is not simply humanlike, but which goes beyond existing human beings," he said. A perfectly symmetrical humanoid will potentially begin to look less and less human. His goal, he said, is to discover how far one can go in this direction while still retaining human characteristics.
The more humanoids begin to look like humans, the creepier they tend to become. This is called the "uncanny valley" and has long been the upper threshold of humanoid development. Although it may depend on how and where the humanoids are used, the birth of a robot that is indistinguishable from humans could come sooner than we think.