Special report: Automotive MEMS drive themselves

Automotive intelligence opens the throttle on the era of anytime, anywhere connectivity. We report on the progress, and point out the speed bumps, in our special all-digital edition. Following is a story from the Special edition on Automotive Intelligence, our latest multimedia report. -- Nicolas Mokhoff, ed.

LONDON --Microelectromechanical systems made from etched silicon started out as an alternative form of pressure sensor for industrial and extreme­ environment ap­plications in the 1980s, in an imple­mentation pioneered by Motorola.

In the 1990s, MEMS devices hit the mainstream as accelerometers for automotive airbag sensors. From there, MEMS devices went on to function as "drop" sensors in hard drives before finding myriad slots in consumer electronics controls. "Automotive is still a very big market [for MEMS], and one of the big applications is [still] the airbag sensor. We reckon there are three to 3.2 airbag sensors per vehicle," said Laurent Robin, market analyst for inertial sensors at market research company Yole Développement.

The MEMS market was worth about $8.7 billion in 2010, according to Yole; automotive MEMS claimed about $1.48 bil­lion of that total, or 17 percent. The market is set to grow by 8 percent in value terms in 2011, Robin said; but the dollar growth fig­ure, mitigated by strong downward price pres­sure of 5 to 20 percent per year, does not reflect the market’s strong unit growth.

The main types of MEMS sensors in automotive use are pressure sensors, used in tire pressure monitoring system (TPMS) designs; accelerometers, used in airbags; and gyroscopes, used for orientation and electronic stability control.

Although the number of cars produced each year is climbing, as is the number of electronic subsystems per car, the automo­tive MEMS market is largely driven by man­date and regulations, said Marco Ferraresi, automotive business development manager for STMicroelectronics.

The TPMS mandate, for example, was intro­duced in the United States in 2007; in the European Union, starting in 2012, all new passenger cars must be equipped with TPMS solutions that meet even tighter specifica­tions than in the States, Ferraresi said. Japan is expected to adapt the EU legislation for its industry approximately one year after the European rollout, said Ferraresi, and South Korea is expected to introduce the legal re­quirement for TPMS in 2013.

"Airbags, which use accelerometers as part of a trigger, are standard in the United States and Europe but not in the BRIC coun­tries," Ferraresi added. But "airbags are coming in Brazil and China" and are likely to be mandated in those countries eventually, presenting a growth opportunity for MEMS.

Meanwhile, demand is high in Brazil for sub­systems that track stolen vehicles. The tech­nology is GPS­based, but accelerometers are used for the wake­up function. The vehicle­tracking market also presents a medium­term opportunity for inertial sensors, including gyroscopes, Ferraresi said.