New Games Use Motion-Sensitive Controls

The mechanical part of a motion-sensing chip used in the controller for Nintendo Co.'s Wii game console is shown above on top of a penny to illustrate its size, Tuesday, Nov. 14, 2006, in New York. The chip, made of silicon using the same techniques used to make electronic chips, contains two spring-loaded weights and is packaged together with an electronic component into the larger assembly seen on the lower part of the coin. The chip is supplied by STMicroelectronics NV. (AP Photo/Mark Lennihan) (Mark Lennihan - AP)

So where has this technology been until now?

Accelerometers have been used to guide missiles and aircraft, said Richard Marks, who worked on an underwater robot before his job as head of special projects at Sony Computer Entertainment America.

"We had a $25,000 inertial system that was probably comparable," to the one in the Sony controller, he said. "These things have become so much less expensive."

In the past, accelerometers were large mechanical devices, with springs or liquids that sensed orientation and movement. The reason they can go into game devices now is that they're made not by assembling mechanical components, but with the same techniques used to make computer chips.

Vigna described a method of successively adding and etching away layers of silicon on large platters with hundreds of individual chips to build up the mechanical part of the accelerometer. The platters are then broken up into individual chips. That means the chips can be made consistently and cheaply with precision down to the micron _ one millionth of a meter, or about one hundredth of the width of a human hair.

Other so-called microelectromechanical systems, or MEMS, that are made in similar ways include chips in video projectors (where they flip thousands of tiny mirrors to build up the image) and in inkjet heads. MEMS technology is seen as a fertile field and is related to another hyped area, nanotechnology (which deals with even smaller scales).

The auto industry started using silicon accelerometers in the late 1980s for the sensors that activate air bags, Vigna said, and each successive generation since then has become smaller and cheaper.

"What ST is doing now is bringing this from the automotive industry to the consumer," Vigna said.

ST says their chip now costs "less than $1 per axis," but wouldn't say exactly what Nintendo is paying.

Accelerometers have made their appearance in game equipment before. In the late 1990s, Microsoft Corp. put out a game controller with a limited "tilt" function, but it never did well. In 2001, Nintendo released a Game Boy Color cartridge that sensed motion, but it worked only for the included game.

But with the Sony and Nintendo controller, accelerometers look set for a breakout in consumer devices.

Laptop makers, including Sony, Lenovo Group Ltd. and Apple Computer Inc., are using them to detect when a computer is in free fall. This signals the read/write heads of the hard drive to park, preventing damage when the laptop lands.

ST has big hopes for the cell-phone market, and is in talks with three phone manufacturers, according to Vigna.

Nokia this year launched a "sports" cell phone, the 5500, with an accelerometer that not only controls a game, but works as a pedometer as well. Other potential uses for such a chip in a phone include managing the user interface: pat the phone or flip it over to send a call to voicemail, Vigna suggested.