What is wearable computing? The simplest definition is any electronic device that's designed to operate on your body. A Bluetooth headset would be an easy example, but incomplete. Wearable computing should do more than replace wires. It should compute, communicate, and connect. Thanks to the efforts of companies large and small, wearable computing will soon achieve the potential of its name -- computers so close, they're practically a part of you.

This is the trend that will define the next computing revolution. Each stage of computing progress has driven us toward greater integration of man and machine. PCs were distant. Mobile was intimate. Wearable computing will be as close to a cyborg existence as most human beings will ever get. It's already in motion, so it's up to you to learn more before you get left behind.

Here, you'll learn as much about the hardware behind this wearable revolution as I can teach you -- within reason, of course, and with fair use of the trusty crystal ball. Let's get right to it.

Controlling the wearable revolution
To be clear, "hardware" refers to any part of your wearable computing getup that acts as or controls the nerve center of the entire operation. Sophisticated software will run through these elements, and you'll control that software directly through your commands to these pieces.

The first major part of your wearable computing revolution will be your smartphone, or something like it. A flat screen of reasonable size will still be important for direct input, though you won't use it much when you're not issuing commands. It'll probably be wrist-worn, as Apple's (Nasdaq: AAPL) iPods occasionally are today. The truly dedicated might even implant magnetic connectors in their wrist to secure the device, as one body-mod enthusiast in New Jersey did earlier this year. These devices will probably be commoditized quickly since their development won't require extremely substantial changes to already-existing products.

The computer is a part of you
The central hub of your wearable computing experience will likely be an augmented-reality projected display, worn as eyeglasses. Google (Nasdaq: GOOG) created a viral sensation when it first publicized Project Glass, the first such functional device aimed squarely at the consumer market. The device has since been used to stage a team skydive into Google's developer conference, and will become available to early developers in 2013.

Apple's also moving into the face space, but its known efforts are limited to a patent for "peripheral treatment for head-mounted displays." It'll probably be named "iGlass," but "iFace" could be a dark-horse handle. Apple's product-design prowess might be an even greater advantage here than it has been in mobile devices. However, its software will also have to be near-flawless, and here Google will likely have a multiyear development head start.

Head-worn display technology tends to take up the same facial real estate as glasses. That's a major opportunity for Luxottica, which is by far the largest eyeglass and sunglass manufacturer in the world. Luxottica owns or licenses virtually every major brand in this space, and it would be a natural extension for it to provide fashion expertise and support to head-mounted manufacturers. It could also push into the technology on its own -- the company's long wearable-tech history has generated a 600-patent-deep innovation portfolio.

Controlling the screen
Wearable displays will almost certainly use voice control functionality as well as touch control. These voice commands will most likely be routed through cloud servers for processing purposes, much as Apple's Siri and Google's voice controls are today. Because of this need, integrated wireless connectivity will be even more important in head-mounted computing than it is in current mobile devices. Hardware real estate will be a bit constrained, unless users are willing to look like complete dorks.

Several major microprocessor manufacturers already produce such chips, most notably Qualcomm, but NVIDIA (Nasdaq: NVDA) and Intel are both working on integrated chip designs as well. My fellow Fool Evan Niu covered Intel and NVIDIA's efforts earlier this year, and you can click here to read more.

Some will win, some will lose
There are losers in every great technological leap forward. PC and display manufacturers are likely to be on the firing line. When your display is always in front of you, will you really need a PC and a monitor? They won't disappear, but Hewlett-Packard and Dell have an awful track record of adapting to the new mobile reality. That doesn't bode well for their future success.

Makers of costly display components will also be squeezed as people move more of their interactions in front of their faces. Corning (NYSE: GLW) is already struggling with the commoditization of big-screen displays. A shift to head-mounted augmented reality might make its smartphone initiatives irrelevant before they become fully established. Universal Display (Nasdaq: PANL) is in better shape, but it also risks falling behind if its various LED technologies are partly replaced by projection hardware.

The pieces come together
Hardware is only one element of the wearable computing revolution. Sophisticated sensors, which will take in your movement, field of vision, and the state and position of your body, will also be vital to effective wearable interfaces. Those wearable interfaces will require some of the best software ever designed, because it will need to be more connected to our lives than any software we've used before.

I've covered those aspects of wearable computing in companion articles that you can read here:

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