When you swung a Nintendo Wii remote fitted with Wii MotionPlus, a tiny InvenSense gyroscope measured the turn. The Sunnyvale company built motion sensors on silicon: chips with microscopic moving parts that sense rotation and tilt. Nintendo accounted for a big share of its sales, and its prospectus warned that Wii sales were falling. When InvenSense went public in November 2011, smartphones were the next market, and the company wanted its sensors in every one.

Gyroscopes on a Chip

Steve Nasiri founded InvenSense in California in 2003. Gyroscopes had been large and costly. InvenSense used its own manufacturing process to put them on chips small and cheap enough for consumer gadgets. It then combined gyroscopes with accelerometers in single packages, with software to fuse their readings. The first big win was gaming. Next came camera image stabilization and phones, where motion sensing powered screen rotation and games.

Phones, Then TDK

InvenSense priced its IPO at $7.50 a share in November 2011 on the New York Stock Exchange. Its sensors went into popular smartphones, and its revenue grew fast. Competition from larger chipmakers squeezed prices, and Nasiri left the company in 2012. In December 2016 Japan's TDK agreed to buy InvenSense for about $1.3 billion, and the deal closed in 2017. It now operates as TDK InvenSense.

Cover: Acrobats at the Cirque Fernando (Francisca and Angelina Wartenberg), Pierre-Auguste Renoir. Art Institute of Chicago, public domain. Chosen for young acrobats (balance and motion).