How Wearable Technology Works

The end goal of wearable technology is to make tasks easier, more efficient, more effective or simply more fun. All of these devices are part of the so-called quantified-self movement, which is about blending each aspect of your life with technology that continuously gathers and crunches data.

Whether you're consciously seeking to collect data regarding every moment of your life or you just want to track the metrics of your morning jog, wearable technology functions in all sorts of interesting and helpful ways. Ultimately, they're all part of the Internet of things, an all-encompassing phrase that describes interconnected digital gadgets that log, report and control data from your body and across the planet.

Right now, smartphones are a linchpin in this system. Smartphones paired with the right app or hardware become a hub for hundreds of activities and purposes. Because they can send data to and from the Internet, they provide a way to integrate connectivity options into all sorts of wearable goods.

Google Glass is a prime example of the current evolution of wearable technology. Glass is a computer in the form of a pair of eyeglasses and includes an optical head-mounted display. In short, Glass does a lot of the things that your smartphone can do. For instance, you can use a voice command to display a map and then use your finger to swipe through driving directions. The Glass does have WiFi capability, but when you're out of range, you can switch to Bluetooth, which connects to the Internet via your smartphone.

It has GPS, a camera, a microphone and 16GB of internal flash memory (12 user accessible). You can conduct video calls, send pictures and video clips, check your e-mail, post to Facebook and Twitter and a whole lot more.

Glass, though, is just one well-publicized incarnation of wearable technology — and it's still in testing. On the next page you'll delve into one of the biggest markets for body-mounted tech.

The term wearable technology implies that these devices rest on your body. So it's only natural that many of them focus on the wearer's health and fitness.

Smart watches are among the most established wearable tech. Often, these stylish watches come with integrated GPS to log the distance and time of your workout, and many versions will keep tabs on your heart rate, cadence and calories burned. Nowadays, the tech wizardry is getting more magical. With the correct sensor and power source, a wearable item can track just about any metric you want.

Smart medical devices already measure the blood glucose levels in diabetics, helping them monitor their condition and preventing life-threatening situations [source: Guk et al]. Digitized wristbands could warn food service or medical technicians when they haven't sufficiently washed their hands, which could prevent the spread of myriad diseases and improve public health.

Some products are already a reality, including Cityzen Smart Sensing fabric. "Smart" because it combines tiny sensors into a comfortable garment, which can be anything from mittens to pants, depending on the application. Connect the garment to a compact, battery-powered transmitter, turn on your smartphone's Bluetooth connection, and suddenly you have a customized body monitoring system.

The fabric communicates with an app on your phone to keep tabs on heart rate, respiration and metrics. Ultimately, the system notes how tired or stressed you are, and could even alert you to the onset of a medical problem. In spite of its high-tech nature, you can wash and iron the Smart Sensing fabric normally [course: Haseltine].

The gaming industry is bigger than ever, with cinematic appeal and wow-inducing special effects. Still, the games would be more immersive with more life-like control systems. That's what the PrioVR plans to deliver.

Depending on the model, you'll attach between eight and 17 inertial sensors to your body. As you play a game, the sensors correlate your real-life movements to your on-screen character. The wearable nature of PrioVR — a gaming suit that players don for motion-capture action gaming — advertises more accurate movement than data captured from remote cameras or handheld devices, which the company hopes will mean more fun.

Desperate to improve your baseball, golf or tennis swing? Attach a small, square Zepp sensor to your glove or equipment and you'll have immediate feedback on speed, acceleration, line of sight and power. The small sensors recharge via a USB port and they work directly with both iOS and Android smartphone apps via Bluetooth. For example, if you're practicing your golf swing, the Zepp app will provide instant statistical data on club plane, hand plane, backswing distance, tempo and hip rotation. You can also watch an animated playback of your swing so you can see areas that need improvement.

One of the primary challenges of wearable technology lies in making it less visible and less, well, dorky. For starters, let's talk looks.

Whether you're a fashionista, hipster or Wall Street huckster, fashion matters. Your choice of clothing provides social cues to others about who you are as a person. And in a world where no one — no one — is cool enough to pull off a Bluetooth cellphone headset, manufacturers know that their products must have a certain amount of sex appeal, otherwise they'll draw ceaseless chortles and rolled eyes.

The Move tank top is a prime example of wearable tech being both functional and fashionable. This stretchy garment looks like a hip yoga outfit, but it's interlaced with sensors and actuators to help you improve your workout form. Bend too far for a specific yoga move, and the Move gently buzzes the offending area of your body. The end result is better form and reduced chance of injury, all combined into an outfit that draws eyes in a good way.

Function is another matter entirely. Intertwining electronics with fabrics brings to mind that horrible shirt tag itch, times 10. The skin recoils at the thought of sensors scratching away, all day long. But engineers are surmounting comfort and user-friendliness issues.

Researchers at the Polytechnic School in Montreal have built touch-sensitive controls right into clothing. They coated copper wires with polymer in a size small enough (less than a millimeter in diameter) to be woven into textiles that, notably, are made with legacy manufacturing processes.

The end result could be a shirt that changes the volume of your headphones. Or a car seat that you swipe to change the seat position, or perhaps turn the heater up or down. These fabrics wash just like any other type of material, an important trait when battling the dirt and stains of everyday life.

Of course, electronics without a power source are rather pointless. The same researchers have also found a way to make a soft, flexible lithium-ion battery that looks a lot like artificial leather. This material, too, can be woven into clothes to power a range of gadgets, providing hundreds of volts throughout the day.

For years now, engineers have been working to integrate piezoelectric components into clothing. Piezoelectricity is electricity generated by mechanical stress — in other words, bending. The minute piezoelectric parts that make this kind of energy are also sometimes called nanogenerators.

When tiny piezoelectric components bend, they generate a detectable electrical charge. Imbed these components into clothing, run several dozen miles, and you could help solve the energy crisis, right?

That idea isn't quite as far-fetched as it seems. Dance clubs have installed floors with piezoelectric parts, which bend when people dance on them. That energy is then used to power other areas of the club, such as lights or the sound system. Furthermore, a company could place the same kinds of components into, say, a soldier's boots. Each step would literally provide power to an array of battlefield devices.

One catch is that piezoelectric materials don't generally product a strong electrical discharge. Often that energy is measured in only millivolts or nanoamps. But with better ways to harvest and store the energy on a person, it could be captured, saved and funneled towards power-hungry gear in the near future.

For a soldier or adventurer stranded for days without access to electrical outlets, this kind of technology holds great potential. Suddenly, there would be a way to revive depleted batteries in a satellite phone or GPS unit. A situation that was once potentially deadly could be managed much more easily just by simply walking around for a while.

Energy-capturing clothing is still in prototype stage. Barring sudden breakthroughs in research and manufacturing, it may be years before consumer-grade shirts and shoes can turn our elbow grease into measureable electrical pulses.

With all of the obvious potential for smart devices, you might wonder why these devices haven't already taken over our tech-driven lives. There are the usual pitfalls to predicting a product's popularity, and much of the discussion circles back to expense.

Digital versions of products we already have are obviously going to cost more to make. And manufacturers aren't keen on retooling their production equipment unless they're sure they can turn a profit on the end product. Consumers, for their part, might light up at the idea of owning a pair of pants that can charge their smartphone, but the concept might not be as exciting once they see the price tag.

There's also the balance between wanting and actually needing more technology. Sure, AR glasses may instantly offer up walking directions and restaurant reviews. But is it really a necessary evolution in consumer technology? Or is it just a way to stroke your digital ego and impress your Glass-less friends?

Then there are privacy and security issues. At this point, most everyone who owns a cell phone understands that privacy is perhaps a forgotten concept. Yet a health-monitoring wearable device, hacked by a soulless offender, could expose very private information to the wider world.

Wearable devices are an enticing adventure for anyone who uses digital gadgets. Perhaps one day soon you'll never have to worry about losing your phone again — it will simply be built into your turtleneck.