Why Should We Be Friends?

Meet Wakamaru and Roomba, two householdhelper robots with very different pedigrees. Wakamaru, from Mitsubishi Heavy Industries, is a waist-high bot with a canary yellow exterior and limpid eyes. It can recognize 10,000 Japanese words, identify eight family members by face or voice, remind you to make an appointment or take your meds and, if somebody breaks into your house, send photographs of the intruder to your mobile phone. When the machine rolled off the assembly line in 2005, Mitsubishi expected U.S. sales to reach 10,000 models a year, despite the bot's $15,000 price tag. Instead, the company filled only a few dozen orders. Wakamaru is now off the market and being rented out as a receptionist at $1,000 a day.

Roomba, by contrast, looks more like an appliance than a robotic friend. The Frisbee-like disc's sole purpose is to vacuum, which it does automatically, thanks to sensors that adjust the settings to suit different floor types, avoid drop-offs like stairs and navigate between table legs and household pets. Starting price: $130. Massachusetts firm iRobot Corp. has sold more than 3 million of the machines.

Wakamaru and Roomba represent radically different approaches to the next big thing in robotics: the use of robot assistants in the office, hospital and home. The Japanese, who have long been fascinated by the robot as android, are concentrating on making machines that look and act like human beings. U.S. firms, on the other hand, have eschewed the flashier android approach and instead are emphasizing products that, like Roomba, are narrowly targeted to specific tasks like mowing lawns, cleaning pools and taking patients' vital signs.

So far, the success of Roomba suggests that the U.S. firms have the upper hand. But the race is only beginning and the stakes are potentially huge. The market for personal and service robots is about $3 billion now but is expected to reach $15 billion by 2015, according to the Japan Robotics Association and market analysts like ABI Research. In 10 years or so, experts predict, sales of personal robots could surpass sales of industrial robots, now about $4.6 billion a year.

The issue for robot developers is whether the technology of artificial intelligence will allow Japanese developers to fulfill their vision of friendly robots capable of working alongside people. If so, Japan could be in a position to dominate the next phase of robotics. If not, the Americans, with their pragmatic but uninspiring designs, could win the race.

Japan approaches this new market from a position of strength. Over the past 50 years, it has become the undisputed leader in industrial robots, supplying 40 percent of the world market. At the same time, Japanese pop culture has become saturated with images of friendly droids from manga cartoons and animé, and bots by Sony and Honda are as famous in Tokyo as Jessica Simpson is in Texas. Japan's robot industry—with the help of $100 million in research funding from the government—is driven in large part by the dream of a day when droids will aid humans in almost every aspect of daily life.