SAN JOSE, Calif. — A secret side project for a Hewlett-Packard engineer has quietly spawned an ultra-sensitive accelerometer. Now the PC giant hopes to leverage the novel device to propel it into a position in sensor networks, an emerging market it sees as the next big wave of computing.

HP claims its MEMS-based motion sensor is a thousand times more sensitive than the devices used in today's game controllers and air bags at a roughly similar size, power and cost. The company is using the device to lure partners across a wide range of vertical markets who want HP to design sensor network systems for them using the accelerometer.

The HP sensor can measure motions of less than 100 nano-Gs per root Hertz. By comparison, the gravitational pull the moon exerts on a single human being is about three micro-Gs, or thirty times the level the HP sensor can measure.

Inside HP's 100 nano-G accelerometer. Click on image to enlarge.

Such sensors could be highly valuable for applications such as mining for oil or gas, or monitoring traffic, cargo shipments or the integrity of a large structure such as an airplane.

"Dozens or hundreds of these sensors could be put on a bridge to show its performance under changing load or temperature to detect a change in vibration before a catastrophic event," said Rich Duncombe, a distinguished technologist and strategist in HP's technology development group..

Market watcher Frost & Sullivan estimates the sensor network market is growing about ten percent a year and will reach nearly $70 billion by 2013. HP sees this market as a fourth wave of computing it dubs "IT everywhere," although it's current growth rate is about that of the PC.