This is the second half of a two-part series on technology breakthroughs that have the potential to change computing. Last week, we looked at five chip-level innovations that will make electronic devices faster, more powerful, more flexible and less expensive to manufacture. This week, we explore advances in how we access the Net, how we power our devices and how we interact with them.
From over-the-air power to neural computer control, each of these technologies has the ability to fundamentally alter the digital landscape. Put them together with the circuit advances we discussed last week, and you get a revolution in the way computers and electronics are designed, manufactured and used.
Extreme wireless: Multi-gigabit Wi-Fi
As great as it is to be able to grab data out of thin air, Wi-Fi is basically 1990s technology that's been jazzed up several times. "We want to take Wi-Fi truly into the 21st century," says Ali Sadri, president and chairman of the Wireless Gigabit Alliance. This consortium of tech companies has developed a specification known as WiGig (download PDF) that supports wireless communications at multi-gigabit speeds.
"With the emphasis on high-definition video, usage of the Web is changing," notes Sadri, who is also marketing director for Intel's wireless group. "Unfortunately, Wi-Fi hasn't kept up. Faster is always better."
Wi-Fi depends on the IEEE's 802.11 family of standards. 802.11a equipment, introduced in 1999, operates on the 5GHz radio band, while later 802.11b and g devices use the crowded 2.4GHz band. The most current dual-band 802.11n gear can operate on either band. Each 802.11 update has increased Wi-Fi's speed incrementally.
WiGig adds the 60GHz transmission band to the mix. With much more available spectrum than the 2.4GHz and 5GHz bands, the 60GHz band allows significantly faster throughput. (See Network World's informative video "How 60GHz will affect Wi-Fi" by Farpoint Group analyst Craig Mathias for details.) WiGig can operate at up to 7Gbps, more than an order of magnitude faster than today's 802.11n Wi-Fi, which can operate at up to 600Mbps.
In other words, WiGig delivers true multi-gigabit throughput -- enough to transmit an entire HD movie in a matter of seconds or smoothly stream it to a viewer. It also offers enough bandwidth to satisfy households with several data-hungry users connected at once -- such as a young child playing an online game in the den, a parent downloading a video-heavy work presentation in the kitchen and a teenager video-chatting with her boyfriend in the dining room.
WiGig could also be used to connect computers to peripherals, such as HD monitors or network hard drives, without a cable in sight. The new wireless spec is also compatible with current Wi-Fi devices.
Enhancing WiGig's speed is a cool trick called beam-forming. Unlike most wireless data systems, WiGig's signal doesn't spread out in a sphere, with most of it wasted. WiGig is smart enough to adjust the antenna parameters at both the sender and receiver to create a focused beam of data for a direct link that has minimal interference. Beam-forming technology is already being used in some Wi-Fi products, but unlike other Wi-Fi standards, WiGig actually relies on it.
"Beam-forming technology is very cool," says David Seiler, chief of the Semiconductor Electronics Division at the Commerce Department's National Institute of Standards and Technology (NIST). "It's what makes high-speed wireless like WiGig possible, and it will be used in a lot of other areas." Because WiGig is based on the same 802.11 specs as Wi-Fi, this technique can "extend the usefulness of Wi-Fi by five to 10 years," he adds.
There is a downside, though: WiGig's top speed has a range of only 45 feet. This will be a problem for home users who want to, say, connect a TV in the bedroom with a router in the basement, or for a business that wants to connect all of the employees in a small office wirelessly.
Sadri mentions two different ways to overcome WiGig's range limitation, neither of which is perfect. One possibility is to set up personal area networks (PAN) for each room or section of a home or office. That way, each PAN segment could pass along the data to the segment in the next room or section, although latency would increase each time the signal is relayed.
The other approach is a little more old-fashioned and involves installing gigabit Ethernet cables as a backbone for several WiGig transmitters placed in strategic locations throughout the building -- a solution that's likely more feasible for small businesses than it would be for home users because it requires running cables behind walls.
And, of course, WiGig will require a new generation of Wi-Fi routers and receivers that use the 60GHz transmission band. Armed with tri-band radios, these devices will also be able to operate on the 2.4GHz and 5GHz bands for interoperability with today's Wi-Fi equipment.
By the end of the year, Sadri expects four semiconductor companies, which he declined to name, to produce samples of WiGig's reference design chip for a new generation of wireless electronics. The needed chips should be in full production in 2012, he says.
By 2013, WiGig devices could be in TVs, computers, phones, tablets and other electronics, and eventually "a few uses we can't even imagine today," says Sadri.
Self-powered electronics: Power without the plug
Zhong Lin Wang dreams of electronic devices that can power themselves. If the materials science professor at the Georgia Institute of Technology's Nanoscience Research Group has his way, replacing or recharging batteries could soon seem "so 2010."
Wang's team at Georgia Tech has designed tiny generators that can produce enough energy to power very small devices. These high-output nanogenerators, HONGs for short, can produce between 2 and 10 volts from a flexible chip smaller than a fingernail.
The design starts with a microscopic array of zinc oxide (ZnO) fibers, or nanowires, each thinner than a human hair. These fiber arrays are embedded into multiple layers of metal electrodes and plastic polymers to create a flexible nanowire "sandwich."
Under an electron microscope, the strands look like the bristles of a very small brush, and they have the seemingly magical piezoelectric property of producing a tiny electrical current when moved or squeezed. Put billions of them together, and you get enough energy to power devices without using an external source of electricity.
"We turn motion into power," says Wang. So far, HONG devices have lit LED lights, run calculator LCD screens and powered rudimentary electronics in the lab. That's just the beginning.
Wang and his team are working on creating HONGs that can power complete wireless devices. Their current project is to make self-powered environmental sensors for a variety of uses.
For instance, the Georgia Tech team is working on a sensor that could be embedded in a bridge. "Surrounded by concrete, it wouldn't be easy to change the sensor's batteries," Wang quips. But with a HONG generator inside, the sensor could be powered by the vibrations of cars and trucks driving over the bridge.
The idea is that every 30 minutes, the sensor -- and dozens like it in the structure -- would send a reading to a receiving station for analysis. If the sensors showed that the bridge was in danger of collapsing, the structure could be shut down, preventing a disaster like the 2007 collapse of the Mississippi River Bridge in Minneapolis.
"This is an especially promising area," says NIST's Seiler. "It lets us think less about the device's battery running out of power and concentrate on what it's supposed to do."
While it's unlikely that nanogenerators will ever generate enough power to support large electronic devices like computers or TVs, a plethora of small devices could eventually be solely or partially powered by HONG chips. By 2013, Wang sees self-powered phones, digital music players and even a wireless keyboard powered by nothing more than the musician's keystrokes.
Wang says that the cost of adding a nanogenerator to devices would be low, because zinc oxide is a common material and HONGs are made with current semiconductor processing technology -- although some evolution of processing techniques will be needed. Additionally, HONG chips could lower the cost of certain products by partially or totally doing away with the need for a battery -- one of the most expensive components of any phone or music player.
Members of Wang's research group are also experimenting with more exotic, and potentially higher-power, piezoelectric compounds such as lead zirconate titanate, but they might be harder to process.
The bottom line is that for many of the electronic devices that surround us, the tyranny of the AC outlet and charger may end. "Motion is everywhere, waiting to be used for powering our future," says Wang. "All we need to do is harness it."
Wireless power: Electricity in the air
More than a century ago, electrical genius Nikola Tesla performed pioneering research and development on many of the things we take for granted today, from X-rays and alternating current electricity to efficient motors and generators and the precursors of radio. But when he turned his vivid imagination to sending electricity over the air with radio waves to power all sorts of devices and appliances without cords, it was an expensive failure.
Fast-forward to the present, where a company called Powercast is doing just what Tesla dreamed of: transmitting power via radio waves. "In a real sense, we're picking up where Tesla left off," says Harry Ostaffe, vice president for marketing and development at the Pittsburgh-based vendor. "We are sending power over the air for devices where it is expensive or inconvenient to change batteries."
Called power harvesting, the technique uses the company's book-size Powercaster transmitter to send either 1 or 3 watts of electricity into the air at the 915MHz radio frequency. At the receiving end, the power is pulled from the air by one of the company's Powerharvester chips, which convert RF energy to DC power.
At the moment, Powercast has two chips: One works best at close range and puts out up to 4.2 volts of continuous electricity for directly powering a very low-power device or charging a battery. The other can be used at longer distances from the transmitter to create an intermittent pulse of up to 5.25 volts for directly powering a low-power device.
These chips can grab small amounts of usable power -- from microwatts to low milliwatts -- out of thin air. That's not enough to run an MP3 player or phone, but it is sufficient for a device that uses very little power, like a Kindle e-book reader, according to Ostaffe.
Rather than developing systems for consumer electronics products, however, Powercast focuses on powering the various sensors that monitor our world, from temperature and pressure sensors in oil refineries to smoke alarms in homes and offices. The typical office today might have a door-position sensor that's part of its security system, a smoke detector, and a motion sensor to turn off the lights if nobody's in the room -- all of which could be powered wirelessly with Powercast's technology.
The company's goal is to eventually develop technology that can extract usable amounts of power from ambient sources such as Wi-Fi signals. But for now its system needs a transmitter to work, which means it's subject to range limitations, Ostaffe says.
"Our biggest enemy is the inverse square law," he jokes. This fundamental law of physics describes how energy radiating outward from a point source -- such as light or in this case radio waves -- is dissipated over distance. The energy available for the receiver falls off very quickly the farther you get from the transmitter.
"Right now, our usable range is about 40 to 45 feet," he says. That's long enough to cover part of a house or a few offices in a building. The typical office facility would probably need 10 or 15 transmitters per 40,000 square feet of floor space, set up around the building's periphery with antennas aimed toward the center.
NIST's Seiler agrees that RF-to-DC power has potential for certain kinds of devices. "It's promising but is limited by range and the amount of power an RF wave can hold. But it could power many smaller devices," he says.
Beam forming: The ability of a wireless communication device to adjust its antenna parameters and tailor its signal directly at the receiver for greater speed and reliability.
Electroencephalography (EEG): The monitoring of the electrical activity of the brain with several electrodes placed on the scalp.
Functional magnetic resonance imaging (fMRI): An offshoot of magnetic resonance imaging, this technology can pinpoint areas of the brain that are being used during an activity.
Inverse square law: A mathematical representation of how energy is dispersed over space, the inverse square law is useful in describing gravity, light, sound and all sorts of radiation. Energy falls off based on the square of the distance, so every time the distance is doubled, the energy available is one quarter of the original amount.
Piezoelectric materials: Piezoelectrics, like zinc oxide, are crystals that create electricity when squeezed or moved. They are used as sparkers in stoves, as sensors and as actuators.