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The Mechanics of Motion Sensing
Dr. Eggman writes, "The AP has a short technology piece on the mechanics that go into the motion-sensing capabilities of the Wii and PS3 controllers. It also details some of the past uses of the technology and gives a nice overview of just how far the technology has come from the earliest missile-guidance sensor equipment."
They're so minute and move so little you will never have to worry about them breaking. Because they are so tiny you can never build up appreciable inertia in them. They are functionally considered solid state devices and they should last pretty much forever.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
A good picture of a two-axis accelerometer can be seen here: http://users.wpi.edu/~cfurlong/me-593Mech.html (second picture down). Sensing is usually performed by capacitive combs, structures which act as capacitors, with their capacitance varying with displacement.
MEMS accelerometers have dropped in price in recent years because there's a big market: the automotive sector. A typical new car needs two accelerometers, one for the traction control system measuring roughly plus-or-minus 2 to 4g, and one for airbag deployment measuring more like 50g.
Two big manufacturers are Analog Devices and ST Microelectronics, though others exist.
The high demand of the automotive sector has driven prices right down; sensors which would have cost hundreds of dollars in the past can now be purchased in bulk for less than $4. In fact, you could order one right now; component retailers will sell you one for less than $15.
"Goodness me, how unlike the FBI to abuse the trust of the American public." -- The Onion
The Nintendo Wii Remote one-ups the Sony controller by including an infrared camera.
I think they meant to say: The Sony controller dumbed down the Wii Remote by excluding the infrared camera.
Hobby Robotics
Should - and do. One of Freescale Semiconductor's clients' more popular uses for accelerometers is in industrial applications -- BIG kit -- on things that vibrate constantly. Things that vibrate more and more as bearings dry or wear (hence the need for the accelerometer - so you can perform detect this and perform maintenance before your printing press, or whatever, self-destructs). The accelerometers outlive any of the parts they are supposed to look after.
Freescale has some pretty cool electonmicrographs of their 2-axis and 3-axis accelerometers - www.freescale.com, sensors, accelerometers, and browse around - I can't actually find the images now. I have a PPT on my work laptop, but that's no use. Grab a ZSTAR for <$50, and simply have a play with one yourself - (that includes everything - hardware and development kit).
Also FatPhil on SoylentNews, id 863