25 March 2010—Nowadays, a phone that doesn’t know where it is or where it’s going can’t really call itself ”smart.” To orient themselves properly, smartphones require not just GPS capability but also an electronic compass, an accelerometer, and increasingly, digital gyroscopes.
The point of a gyroscope is to sense any change in an object’s axis of rotation. Up until now, gyroscopes measured movement around the three axes with three sensors—one for pitch, one for yaw, and another for roll. At most, two of these sensors would be combined on a single die. The best you could do was, say, match up a 3- by 5- by 1-millimeter yaw sensor with a 4- by 5- by 1-mm sensor that would detect pitch and roll. But on 15 February, STMicroelectronics unveiled a 4- by 4- by 1-mm gyroscope whose single sensing structure tracks all three angular motions. It’s a triumph of microelectromechanical systems (MEMS) engineering.