An Accelerated Opening Olympic Cermony

The Olympics are over and we can all return to our regular lives without waiting to see which country has the most gold medals, who is up in the overall medal count, whether the favorite will make it across the finish line or whether some newcomer will cause a worldwide upset... If you watch the Games, which have been around since 776BC, you know that the Opening ceremonies are a grand spectacle with every host nation trying to outdo the one before.

This year, Vancouver had a grand task ahead of them, but no one can forget the splendor, precision and grandeur of the Beijing Summer Olympics. To say that no detail was left uncovered would be an understatement. Everything down the to the items people would wave in the stands was preconceived. The Olympics brought to mind one of the marquee application using MEMS accelerometers that left every viewer at the game with a piece of this technology.  Forget handwritten signs saying John 3:16 or foam fingers in your team colors, viewers at the Beijing games were given a Waving Torch, a replica of the Olympic Torch. Inside each torch, a MEMSIC accelerometer used to detect the beginning and end points of a movement as the torch was waved. On the front edge of the torch, the linear array of LEDs spells out the pre-loaded message in midair by synchronizing the LEDs' illumination with its position in space.

The MEMS-featured torch was definitely not your ordinary flash light, although it could be mistaken for one from a distance. Electronic torches at the Beijing games actually spelled out messages and images, such as the five official Olympic mascots (known as Fuwa), images of many different sports, the Olympic logo and Beijing's Olympic logo, Welcome to Beijing, and many Chinese characters. With the 92,000 viewers in the stadium waving the torches in coordination with the professional performers, the effect created was astounding.

The Olympic stage provided a showcase for MEMSIC's unique thermal sense operating principle that offers a superior motion sensing performance compared with traditional MEMS devices. This MEMS sensor operation is based on the thermal laws of convection and operated like other accels having a static component which is hot air (gas) in MEMSIC's accels.

A single heat source, centered in the silicon chip, creates a thermal gradient and thus a density gradient of the gas in the sealed package. When external forces are applied to the device (such as acceleration, deceleration, gravity, vibration, etc.), the gas moves accordingly within the package due to its minuscule inertial mass. The applied force is detected by sensing and measuring changes in temperature around the heat source. The design has no moving parts, making its MEMS highly reliable - a feature no other MEMS supplier can claim!

A Compass in Every Smartphone - Courtesy of MEMSIC

MEMSIC's capability to address new applications due to the performance vs. price points that their sensors can achieve was recently featured in IEEE Spectrum. Here is an excerpt from the article:

An old axiom says that in order to know where you're going, you first have to know where you are. To that, add that you should know which way you're facing. Makers of wireless handsets, having already installed GPS receivers, are poised to flood the market with phones containing tiny electronic compasses that allow the gadget to sense exactly what direction it's facing.

According to electronics industry analysis firm iSuppli Corp., in El Segundo, Calif., we can expect to see an increasing number of cellphones containing electronic compasses. Analysts predict the market for magnetic compass sensors will grow from the 8.7 million manufactured in 2008 to more than 540 million in 2013.

Underlying the jump is a combination of consumer demand for the whiz-bang feature of the moment and a steep drop in price fueled by manufacturing process improvements.

"Navigation is emerging as a must-have feature in smartphones," says Richard Dixon, a senior analyst at iSuppli. Consumers are already looking to their phones for turn-by-turn directions. With the addition of compasses, the beginnings of location-based augmented reality are also emerging, wherein a street map or even the phone's camera image could be overlaid with highly detailed information about what's in front of you.

The component that handset makers are exploiting to make these feats possible is the three-axis magnetometer. The sensor system's job is to home in on Earth's magnetic field and use that as a reference for determining the handset's orientation along the x-, y-, and z-axes. Three axes are important "because that third sensor allows the handheld device to correct for the orientation of Earth's magnetic field at a given location, as well as the relative position of the device," says Mark Laich, vice president of worldwide sales at Memsic, a maker of electronic compasses based in Andover, Mass. "Otherwise users would have to hold the phone precisely parallel to the ground or in some other position that may not correspond to how they normally use it."

Like the rest of the electronics industry, electronic compass makers have been making their products smaller, cheaper, and more energy efficient. And they reached a watershed moment in 2009, when the price of three-axis magnetometers dipped below US $1 per device. "Six months ago, magnetic sensors were selling at $1.50 each, but the price is coming down rapidly," says Laich. "They're now at the sub-$0.50 point and look to get even cheaper as production volumes increase."

Memsic and other new entrants into the magnetometer market for mobile devices mostly sell sensors that take advantage of amorphous magnetic alloys whose resistances change when acted upon by the planet's magnetic field. Memsic, for example, uses three chips, each containing a thin film of the alloy. The chips, which are set at right angles to each other, are incorporated into a Wheatstone bridge circuit so that when you move the phone, the change in resistance resulting from the perceived change in the strength or direction of the magnetic field is output as a change in voltage.

Aichi Steel, Honeywell, Memsic, and Sensitec have all developed magnetoresistive sensors in an effort to take a bite out of AKM Semiconductor's 95 percent share of the mobile phone compass market. AKM, in San Jose, Calif., uses a technology that relies on the Hall effect, in which electrons racing through a conductor in the presence of a magnetic field are forced to one edge of the conductor, creating a voltage difference whose orientation is perpendicular to the magnetic field. AKM's competitors claim their devices are power misers compared with Hall effect sensors, a really big deal in palm-size devices that barely have room for the batteries they stow. The companies also say that their sensors are more sensitive and have quicker response times.

The competition is making important inroads. Geneva-based STMicroelectronics, a leading accelerometer maker, chose Honeywell's magnetoresistive technology over Hall sensors to make the first single-package combination accelerometer-magnetometer on the market. One reason ST cited was that the device provides the same sensitivity in all three axes without the need for the magnetic flux concentrators that Hall effect sensors require. And as for the degaussing issue, ST found it required only a matter of microamperes.