Microelectromechanical system (MEMS) chips have been built into the Olympic Torch--not the one that traveled around the world, but the replicas that spectators will wave at the 2008 Beijing Summer Olympics.
Fans will be able to spell out messages in midair by brandishing their Waving Torches in the stands. Built-in LEDs will spell out preloaded sayings, or the units can be plugged into a computer for uploading a personalized message, said Yang Zhao, founder of Memsic Inc. (Andover, Mass.), which designed the accelerometer used in the item.
Formerly a MEMS engineer at Analog Devices, Zhao claims he was disheartened while at ADI by the necessity of building a special semiconductor fab for the MEMS process that etches out moving parts in three dimensions on silicon chips. Zhao invented a technology that instead harnesses hot air as its moving part, and formed Memsic to commercialize the approach. According to analysts, Memsic has been a driving force in moving the price of MEMS accelerometers within striking distance of $1 because the devices can be manufactured on any standard CMOS line.
The Waving Torch uses the accelerometer to detect the beginning and end points of a movement as the torch is waved. On the front edge of the torch, the linear array of LEDs spells out the stored message by synchronizing the LEDs' illumination with their position in space. By dividing messages into vertical lines of pixels, the waving action can be used to illuminate each column of the message as the torch moves, because the eye-brain system "remembers" images for a fraction of a second. "Our sensor detects the left end and right end of the motion when you wave the torch," said Zhao. "The one-line LED synthesizes the message by using the human eye's slow response effect to 'store' the pixels after each column is illuminated."
The Waving Torch idea itself is not new; what's novel is using a MEMS chip to measure the movement.
"Memsic's deal with the Olympics committee gives us the authorization to sell the Waving Torch with the Olympic logo at the games in Beijing, as well as at the 5,000 Olympics stores throughout China," Zhao said. p